Java/File Input Output/InputStream
Содержание
- 1 An input stream which reads sequentially from multiple sources
- 2 An limited-data-size input stream
- 3 A trace of the data that is being retrieved from an input stream
- 4 Combined InputStream
- 5 Compare two InputStream
- 6 Convert InputStream to String
- 7 Convert Reader to InputStream
- 8 Creating a Manifest for a JAR File
- 9 Creating an input or output stream on a ByteBuffer
- 10 Deserializes an object from an input stream.
- 11 EOLConvertingInputStream: InputStream which converts \r bytes not followed by \n and \n not preceded by \r to \r\n.
- 12 Minimal InputStream subclass to fetch bytes form a String
- 13 Read and return the entire contents of the supplied InputStream.
- 14 Read and return the entire contents of the supplied InputStream. This method always closes the stream when finished reading.
- 15 Reads at most certain bytes from input stream and returns them as a byte array.
- 16 Size Limit InputStream
An input stream which reads sequentially from multiple sources
<source lang="java">
/*
* Copyright (C) 2004 Stephen Ostermiller * http://ostermiller.org/contact.pl?regarding=Java+Utilities * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * See COPYING.TXT for details. */
import java.io.*; import java.util.ArrayList; /**
* An input stream which reads sequentially from multiple sources. * More information about this class is available from . * * @author Stephen Ostermiller http://ostermiller.org/contact.pl?regarding=Java+Utilities * @since ostermillerutils 1.04.00 */
public class ConcatInputStream extends InputStream {
/** * Current index to inputStreamQueue * * @since ostermillerutils 1.04.01 */ private int inputStreamQueueIndex = 0; /** * Queue of inputStreams that have yet to be read from. * * @since ostermillerutils 1.04.01 */ private ArrayList<InputStream> inputStreamQueue = new ArrayList<InputStream>(); /** * A cache of the current inputStream from the inputStreamQueue * to avoid unneeded access to the queue which must * be synchronized. * * @since ostermillerutils 1.04.01 */ private InputStream currentInputStream = null; /** * true iff the client may add more inputStreams. * * @since ostermillerutils 1.04.01 */ private boolean doneAddingInputStreams = false; /** * Causes the addInputStream method to throw IllegalStateException * and read() methods to return -1 (end of stream) * when there is no more available data.*
* Calling this method when this class is no longer accepting
* more inputStreams has no effect.
*
* @since ostermillerutils 1.04.01
*/
public void lastInputStreamAdded(){
doneAddingInputStreams = true;
}
/**
* Add the given inputStream to the queue of inputStreams from which to
* concatenate data.
*
* @param in InputStream to add to the concatenation.
* @throws IllegalStateException if more inputStreams can"t be added because lastInputStreamAdded() has been called, close() has been called, or a constructor with inputStream parameters was used.
*
* @since ostermillerutils 1.04.01
*/
public void addInputStream(InputStream in){
synchronized(inputStreamQueue){
if (in == null) throw new NullPointerException();
if (closed) throw new IllegalStateException("ConcatInputStream has been closed");
if (doneAddingInputStreams) throw new IllegalStateException("Cannot add more inputStreams - the last inputStream has already been added.");
inputStreamQueue.add(in);
}
}
/**
* Add the given inputStream to the queue of inputStreams from which to
* concatenate data.
*
* @param in InputStream to add to the concatenation.
* @throws IllegalStateException if more inputStreams can"t be added because lastInputStreamAdded() has been called, close() has been called, or a constructor with inputStream parameters was used.
* @throws NullPointerException the array of inputStreams, or any of the contents is null.
*
* @since ostermillerutils 1.04.01
*/
public void addInputStreams(InputStream[] in){
for (InputStream element: in) {
addInputStream(element);
}
}
/**
* Gets the current inputStream, looking at the next
* one in the list if the current one is null.
*
* @since ostermillerutils 1.04.01
*/
private InputStream getCurrentInputStream(){
if (currentInputStream == null && inputStreamQueueIndex < inputStreamQueue.size()){
synchronized(inputStreamQueue){
// inputStream queue index is advanced only by the nextInputStream()
// method. Don"t do it here.
currentInputStream = inputStreamQueue.get(inputStreamQueueIndex);
}
}
return currentInputStream;
}
/**
* Indicate that we are done with the current inputStream and we should
* advance to the next inputStream.
*
* @since ostermillerutils 1.04.01
*/
private void advanceToNextInputStream(){
currentInputStream = null;
inputStreamQueueIndex++;
}
/**
* True iff this the close() method has been called on this stream.
*
* @since ostermillerutils 1.04.00
*/
private boolean closed = false;
/**
* Create a new input stream that can dynamically accept new sources.
* <p>
* New sources should be added using the addInputStream() method.
* When all sources have been added the lastInputStreamAdded() should
* be called so that read methods can return -1 (end of stream).
* <p>
* Adding new sources may by interleaved with read calls.
*
* @since ostermillerutils 1.04.01
*/
public ConcatInputStream(){
// Empty constructor
}
/**
* Create a new InputStream with one source.
*
* @param in InputStream to use as a source.
*
* @throws NullPointerException if in is null
*
* @since ostermillerutils 1.04.00
*/
public ConcatInputStream(InputStream in){
addInputStream(in);
lastInputStreamAdded();
}
/**
* Create a new InputStream with two sources.
*
* @param in1 first InputStream to use as a source.
* @param in2 second InputStream to use as a source.
*
* @throws NullPointerException if either source is null.
*
* @since ostermillerutils 1.04.00
*/
public ConcatInputStream(InputStream in1, InputStream in2){
addInputStream(in1);
addInputStream(in2);
lastInputStreamAdded();
}
/**
* Create a new InputStream with an arbitrary number of sources.
*
* @param in InputStreams to use as a sources.
*
* @throws NullPointerException if the input array on any element is null.
*
* @since ostermillerutils 1.04.00
*/
public ConcatInputStream(InputStream[] in){
addInputStreams(in);
lastInputStreamAdded();
}
/**
* Reads the next byte of data from the underlying streams. The value byte is
* returned as an int in the range 0 to 255. If no byte is available because
* the end of the stream has been reached, the value -1 is returned. This method
* blocks until input data is available, the end of the stream is detected, or
* an exception is thrown.
* <p>
* If this class in not done accepting inputstreams and the end of the last known
* stream is reached, this method will block forever unless another thread
* adds an inputstream or interrupts.
*
* @return the next byte of data, or -1 if the end of the stream is reached.
*
* @throws IOException if an I/O error occurs.
*/
@Override public int read() throws IOException {
if (closed) throw new IOException("InputStream closed");
int r = -1;
while (r == -1){
InputStream in = getCurrentInputStream();
if (in == null){
if (doneAddingInputStreams) return -1;
try {
Thread.sleep(100);
} catch (InterruptedException iox){
throw new IOException("Interrupted");
}
} else {
r = in.read();
if (r == -1) advanceToNextInputStream();
}
}
return r;
}
/**
* Reads some number of bytes from the underlying streams and stores them into
* the buffer array b. The number of bytes actually read is returned as an
* integer. This method blocks until input data is available, end of file is
* detected, or an exception is thrown.
* <p>
* If the length of b is zero,
* then no bytes are read and 0 is returned; otherwise, there is an attempt
* to read at least one byte.
* <p>
* The read(b) method for class InputStream has the same effect as:
* read(b, 0, b.length)
* <p>
* If this class in not done accepting inputstreams and the end of the last known
* stream is reached, this method will block forever unless another thread
* adds an inputstream or interrupts.
*
* @param b - Destination buffer
* @return The number of bytes read, or -1 if the end of the stream has been reached
*
* @throws IOException - If an I/O error occurs
* @throws NullPointerException - If b is null.
*
* @since ostermillerutils 1.04.00
*/
@Override public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
/**
* Reads up to length bytes of data from the underlying streams into an array of bytes.
* An attempt is made to read as many as length bytes, but a smaller number may be read,
* possibly zero. The number of bytes actually read is returned as an integer.
* <p>
* If length is zero,
* then no bytes are read and 0 is returned; otherwise, there is an attempt
* to read at least one byte.
* <p>
* This method blocks until input data is available
* <p>
* If this class in not done accepting inputstreams and the end of the last known
* stream is reached, this method will block forever unless another thread
* adds an inputstream or interrupts.
*
* @param b Destination buffer
* @param off Offset at which to start storing bytes
* @param len Maximum number of bytes to read
* @return The number of bytes read, or -1 if the end of the stream has been reached
*
* @throws IOException - If an I/O error occurs
* @throws NullPointerException - If b is null.
* @throws IndexOutOfBoundsException - if length or offset are not possible.
*/
@Override public int read(byte[] b, int off, int len) throws IOException {
if (off < 0 || len < 0 || off + len > b.length) throw new IllegalArgumentException();
if (closed) throw new IOException("InputStream closed");
int r = -1;
while (r == -1){
InputStream in = getCurrentInputStream();
if (in == null){
if (doneAddingInputStreams) return -1;
try {
Thread.sleep(100);
} catch (InterruptedException iox){
throw new IOException("Interrupted");
}
} else {
r = in.read(b, off, len);
if (r == -1) advanceToNextInputStream();
}
}
return r;
}
/**
* Skips over and discards n bytes of data from this input stream. The skip method
* may, for a variety of reasons, end up skipping over some smaller number of bytes,
* possibly 0. This may result from any of a number of conditions; reaching end of
* file before n bytes have been skipped is only one possibility. The actual number
* of bytes skipped is returned. If n is negative, no bytes are skipped.
* <p>
* If this class in not done accepting inputstreams and the end of the last known
* stream is reached, this method will block forever unless another thread
* adds an inputstream or interrupts.
*
* @param n he number of characters to skip
* @return The number of characters actually skipped
*
* @throws IOException If an I/O error occurs
*
* @since ostermillerutils 1.04.00
*/
@Override public long skip(long n) throws IOException {
if (closed) throw new IOException("InputStream closed");
if (n <= 0) return 0;
long s = -1;
while (s <= 0){
InputStream in = getCurrentInputStream();
if (in == null){
if (doneAddingInputStreams) return 0;
try {
Thread.sleep(100);
} catch (InterruptedException iox){
throw new IOException("Interrupted");
}
} else {
s = in.skip(n);
// When nothing was skipped it is a bit of a puzzle.
// The most common cause is that the end of the underlying
// stream was reached. In which case calling skip on it
// will always return zero. If somebody were calling skip
// until it skipped everything they needed, there would
// be an infinite loop if we were to return zero here.
// If we get zero, let us try to read one character so
// we can see if we are at the end of the stream. If so,
// we will move to the next.
if (s <= 0) {
// read() will advance to the next stream for us, so don"t do it again
s = ((read()==-1)?-1:1);
}
}
}
return s;
}
/**
* Returns the number of bytes that can be read (or skipped over) from this input
* stream without blocking by the next caller of a method for this input stream.
* The next caller might be the same thread or or another thread.
*
* @throws IOException If an I/O error occurs
*
* @since ostermillerutils 1.04.00
*/
@Override public int available() throws IOException {
if (closed) throw new IOException("InputStream closed");
InputStream in = getCurrentInputStream();
if (in == null) return 0;
return in.available();
}
/**
* Closes this input stream and releases any system resources associated with the stream.
*
* @since ostermillerutils 1.04.00
*/
@Override public void close() throws IOException {
if (closed) return;
for (Object element: inputStreamQueue) {
((InputStream)element).close();
}
closed = true;
}
/**
* Mark not supported
*
* @since ostermillerutils 1.04.00
*/
@Override public void mark(int readlimit){
// Mark not supported -- do nothing
}
/**
* Reset not supported.
*
* @throws IOException because reset is not supported.
*
* @since ostermillerutils 1.04.00
*/
@Override public void reset() throws IOException {
throw new IOException("Reset not supported");
}
/**
* Does not support mark.
*
* @return false
*
* @since ostermillerutils 1.04.00
*/
@Override public boolean markSupported(){
return false;
}
}
</source>
An limited-data-size input stream
<source lang="java">
/*
* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */
import java.io.FilterInputStream; import java.io.IOException; import java.io.InputStream;
/**
* An input stream, which limits its data size. This stream is * used, if the content length is unknown. */
public abstract class LimitedInputStream
extends FilterInputStream {
/**
* The maximum size of an item, in bytes.
*/
private long sizeMax;
/**
* The current number of bytes.
*/
private long count;
/**
* Whether this stream is already closed.
*/
private boolean closed;
/**
* Creates a new instance.
* @param pIn The input stream, which shall be limited.
* @param pSizeMax The limit; no more than this number of bytes
* shall be returned by the source stream.
*/
public LimitedInputStream(InputStream pIn, long pSizeMax) {
super(pIn);
sizeMax = pSizeMax;
}
/**
* Called to indicate, that the input streams limit has
* been exceeded.
* @param pSizeMax The input streams limit, in bytes.
* @param pCount The actual number of bytes.
* @throws IOException The called method is expected
* to raise an IOException.
*/
protected abstract void raiseError(long pSizeMax, long pCount)
throws IOException;
/** Called to check, whether the input streams
* limit is reached.
* @throws IOException The given limit is exceeded.
*/
private void checkLimit() throws IOException {
if (count > sizeMax) {
raiseError(sizeMax, count);
}
}
/**
* Reads the next byte of data from this input stream. The value
* byte is returned as an int in the range
* 0 to 255. If no byte is available
* because the end of the stream has been reached, the value
* -1 is returned. This method blocks until input data
* is available, the end of the stream is detected, or an exception
* is thrown.
* <p>
* This method
* simply performs in.read() and returns the result.
*
* @return the next byte of data, or -1 if the end of the
* stream is reached.
* @exception IOException if an I/O error occurs.
* @see java.io.FilterInputStream#in
*/
public int read() throws IOException {
int res = super.read();
if (res != -1) {
count++;
checkLimit();
}
return res;
}
/**
* Reads up to len bytes of data from this input stream
* into an array of bytes. If len is not zero, the method
* blocks until some input is available; otherwise, no
* bytes are read and 0 is returned.
* <p>
* This method simply performs in.read(b, off, len)
* and returns the result.
*
* @param b the buffer into which the data is read.
* @param off The start offset in the destination array
* b.
* @param len the maximum number of bytes read.
* @return the total number of bytes read into the buffer, or
* -1 if there is no more data because the end of
* the stream has been reached.
* @exception NullPointerException If b is null.
* @exception IndexOutOfBoundsException If off is negative,
* len is negative, or len is greater than
* b.length - off
* @exception IOException if an I/O error occurs.
* @see java.io.FilterInputStream#in
*/
public int read(byte[] b, int off, int len) throws IOException {
int res = super.read(b, off, len);
if (res > 0) {
count += res;
checkLimit();
}
return res;
}
/**
* Returns, whether this stream is already closed.
* @return True, if the stream is closed, otherwise false.
* @throws IOException An I/O error occurred.
*/
public boolean isClosed() throws IOException {
return closed;
}
/**
* Closes this input stream and releases any system resources
* associated with the stream.
* This
* method simply performs in.close().
*
* @exception IOException if an I/O error occurs.
* @see java.io.FilterInputStream#in
*/
public void close() throws IOException {
closed = true;
super.close();
}
}
</source>
A trace of the data that is being retrieved from an input stream
<source lang="java">
/*
* The contents of this file are subject to the terms * of the Common Development and Distribution License * (the "License"). You may not use this file except * in compliance with the License. * * You can obtain a copy of the license at * glassfish/bootstrap/legal/CDDLv1.0.txt or * https://glassfish.dev.java.net/public/CDDLv1.0.html. * See the License for the specific language governing * permissions and limitations under the License. * * When distributing Covered Code, include this CDDL * HEADER in each file and include the License file at * glassfish/bootstrap/legal/CDDLv1.0.txt. If applicable, * add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your * own identifying information: Portions Copyright [yyyy] * [name of copyright owner] */
/*
* @(#)TraceInputStream.java 1.7 05/08/29 * * Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved. */
//Revised from sun mail util import java.io.*; /**
* This class is a FilterInputStream that writes the bytes * being read from the given input stream into the given output * stream. This class is typically used to provide a trace of * the data that is being retrieved from an input stream. * * @author John Mani */
public class TraceInputStream extends FilterInputStream {
private boolean trace = false;
private boolean quote = false;
private OutputStream traceOut;
/**
* Creates an input stream filter built on top of the specified
* input stream.
*
* @param in the underlying input stream.
* @param out the trace stream
*/
public TraceInputStream(InputStream in, OutputStream traceOut) {
super(in);
this.traceOut = traceOut;
}
/**
* Set trace mode.
* @param trace the trace mode
*/
public void setTrace(boolean trace) {
this.trace = trace;
}
/**
* Set quote mode.
* @param quote the quote mode
*/
public void setQuote(boolean quote) {
this.quote = quote;
}
/**
* Reads the next byte of data from this input stream. Returns
* -1 if no data is available. Writes out the read
* byte into the trace stream, if trace mode is true
*/
public int read() throws IOException {
int b = in.read();
if (trace && b != -1) {
if (quote)
writeByte(b);
else
traceOut.write(b);
}
return b;
}
/**
* Reads up to len bytes of data from this input stream
* into an array of bytes. Returns -1 if no more data
* is available. Writes out the read bytes into the trace stream, if
* trace mode is true
*/
public int read(byte b[], int off, int len) throws IOException {
int count = in.read(b, off, len);
if (trace && count != -1) {
if (quote) {
for (int i = 0; i < count; i++)
writeByte(b[off + i]);
} else
traceOut.write(b, off, count);
}
return count;
}
/**
* Write a byte in a way that every byte value is printable ASCII.
*/
private final void writeByte(int b) throws IOException {
b &= 0xff;
if (b > 0x7f) {
traceOut.write("M");
traceOut.write("-");
b &= 0x7f;
}
if (b == "\r") {
traceOut.write("\\");
traceOut.write("r");
} else if (b == "\n") {
traceOut.write("\\");
traceOut.write("n");
traceOut.write("\n");
} else if (b == "\t") {
traceOut.write("\\");
traceOut.write("t");
} else if (b < " ") {
traceOut.write("^");
traceOut.write("@" + b);
} else {
traceOut.write(b);
}
}
}
</source>
Combined InputStream
<source lang="java">
/**
* Project pack:tag >> http://packtag.sf.net * * This software is published under the terms of the LGPL * License version 2.1, a copy of which has been included with this * distribution in the "lgpl.txt" file. * * Creation date: 15.04.2007 - 18:27:26 * Last author: $Author: danielgalan $ * Last modified: $Date: 2008/02/10 20:03:21 $ * Revision: $Revision: 1.4 $ * * $Log: CombinedInputStream.java,v $ * Revision 1.4 2008/02/10 20:03:21 danielgalan * Fix for IE - if after a closing bracket a var keyword is, IE can"t interpret this, eg "varx={}var y ={}" mus be seperated: "varx={}\nvar y ={}" * * Revision 1.3 2007/05/02 21:38:38 danielgalan * alias to name * * Revision 1.2 2007/05/02 21:29:18 danielgalan * last fixes for 2.0, attribute media * * Revision 1.1 2007/04/22 19:04:24 danielgalan * pack.tag moved from subversion to good old CVS */
import java.io.IOException; import java.io.InputStream;
/**
* Reads multiple Inputstreams as one * * @author Daniel Galán y Martins * @version $Revision: 1.4 $ */
public class CombinedInputStream extends InputStream {
/** The current Stream to read from */ private int current; boolean isNextLineFeed = false; /** The Streams to combine */ private final InputStream[] streams;
/**
* Constructs an combined InputStream, that reads from array stream per stream, till the last stream
*
* @param streams All Streams that will be combined
*/
public CombinedInputStream(final InputStream[] streams) {
current = 0;
this.streams = streams;
}
/**
* Reads from the list of streams, when the last stream is over, -1 will be returned (as usual)
*/
public int read() throws IOException {
if (isNextLineFeed) {
isNextLineFeed = false;
return "\n";
}
int i = -1;
if (current < streams.length) {
i = streams[current].read();
if (i == -1) {
isNextLineFeed = true;
// the current stream has been finished, use the next one
current++;
return read();
}
}
return i;
}
/** Closes all streams */
public void close() throws IOException {
for (int i = 0; i < streams.length; i++) {
streams[i].close();
}
}
/** Is there more data to read */
public int available() throws IOException {
return current < streams.length ? streams[current].available() : 0;
}
}
</source>
Compare two InputStream
<source lang="java">
/*
* JBoss DNA (http://www.jboss.org/dna) * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. Some portions may be licensed * to Red Hat, Inc. under one or more contributor license agreements. * See the AUTHORS.txt file in the distribution for a full listing of * individual contributors. * * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA * is licensed to you under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * JBoss DNA is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */
import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.Reader; import java.io.Writer; import java.util.Arrays; /**
* @author Randall Hauch */
public class Main {
/**
* Compare two input stream
*
* @param input1 the first stream
* @param input2 the second stream
* @return true if the streams contain the same content, or false otherwise
* @throws IOException
* @throws IllegalArgumentException if the stream is null
*/
public static boolean isSame( InputStream input1,
InputStream input2 ) throws IOException {
boolean error = false;
try {
byte[] buffer1 = new byte[1024];
byte[] buffer2 = new byte[1024];
try {
int numRead1 = 0;
int numRead2 = 0;
while (true) {
numRead1 = input1.read(buffer1);
numRead2 = input2.read(buffer2);
if (numRead1 > -1) {
if (numRead2 != numRead1) return false;
// Otherwise same number of bytes read
if (!Arrays.equals(buffer1, buffer2)) return false;
// Otherwise same bytes read, so continue ...
} else {
// Nothing more in stream 1 ...
return numRead2 < 0;
}
}
} finally {
input1.close();
}
} catch (IOException e) {
error = true; // this error should be thrown, even if there is an error closing stream 2
throw e;
} catch (RuntimeException e) {
error = true; // this error should be thrown, even if there is an error closing stream 2
throw e;
} finally {
try {
input2.close();
} catch (IOException e) {
if (!error) throw e;
}
}
}
}
</source>
Convert InputStream to String
<source lang="java">
import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; public class Main {
public static void main(String[] args) throws Exception {
InputStream is = Main.class.getResourceAsStream("/data.txt");
System.out.println(convertStreamToString(is));
}
public static String convertStreamToString(InputStream is) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
return sb.toString();
}
}
</source>
Convert Reader to InputStream
<source lang="java">
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common
* Development and Distribution License("CDDL") (collectively, the
* "License"). You may not use this file except in compliance with the
* License. You can obtain a copy of the License at
* http://www.netbeans.org/cddl-gplv2.html
* or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
* specific language governing permissions and limitations under the
* License. When distributing the software, include this License Header
* Notice in each file and include the License file at
* nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the
* License Header, with the fields enclosed by brackets [] replaced by
* your own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
*
* Contributor(s):
*
* The Original Software is NetBeans. The Initial Developer of the Original
* Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
* Microsystems, Inc. All Rights Reserved.
*
* If you wish your version of this file to be governed by only the CDDL
* or only the GPL Version 2, indicate your decision by adding
* "[Contributor] elects to include this software in this distribution
* under the [CDDL or GPL Version 2] license." If you do not indicate a
* single choice of license, a recipient has the option to distribute
* your version of this file under either the CDDL, the GPL Version 2 or
* to extend the choice of license to its licensees as provided above.
* However, if you add GPL Version 2 code and therefore, elected the GPL
* Version 2 license, then the option applies only if the new code is
* made subject to such option by the copyright holder.
*/
import java.io.*;
/**
- This class convert Reader to InputStream. It works by converting
- the characters to the encoding specified in constructor parameter.
- @author Petr Hamernik, David Strupl
- /
public class ReaderInputStream extends InputStream {
/** Input Reader class. */
private Reader reader;
private PipedOutputStream pos;
private PipedInputStream pis;
private OutputStreamWriter osw;
/** Creates new input stream from the given reader.
* Uses the platform default encoding.
* @param reader Input reader
*/
public ReaderInputStream(Reader reader) throws IOException {
this.reader = reader;
pos = new PipedOutputStream();
pis = new PipedInputStream(pos);
osw = new OutputStreamWriter(pos);
}
/** Creates new input stream from the given reader and encoding.
* @param reader Input reader
* @param encoding
*/
public ReaderInputStream(Reader reader, String encoding)
throws IOException {
this.reader = reader;
pos = new PipedOutputStream();
pis = new PipedInputStream(pos);
osw = new OutputStreamWriter(pos, encoding);
}
public int read() throws IOException {
if (pis.available() > 0) {
return pis.read();
}
int c = reader.read();
if (c == -1) {
return c;
}
osw.write(c);
osw.flush();
pos.flush();
return pis.read();
}
public int read(byte[] b, int off, int len) throws IOException {
if (len == 0) {
return 0;
}
int c = read();
if (c == -1) {
return -1;
}
b[off] = (byte) c;
int i = 1;
// Don"t try to fill up the buffer if the reader is waiting.
for (; (i < len) && reader.ready(); i++) {
c = read();
if (c == -1) {
return i;
}
b[off + i] = (byte) c;
}
return i;
}
public int available() throws IOException {
int i = pis.available();
if (i > 0) {
return i;
}
if (reader.ready()) {
// Char must produce at least one byte.
return 1;
} else {
return 0;
}
}
public void close() throws IOException {
reader.close();
osw.close();
pis.close();
}
}
</source>
Creating a Manifest for a JAR File
<source lang="java">
import java.io.ByteArrayInputStream; import java.io.FileInputStream; import java.io.InputStream; import java.util.jar.Manifest; public class Main {
public static void main(String[] argv) throws Exception {
// Create a manifest from a file
InputStream fis = new FileInputStream("manifestfile");
Manifest manifest = new Manifest(fis);
// Construct a string version of a manifest
StringBuffer sbuf = new StringBuffer();
sbuf.append("Manifest-Version: 1.0\n");
sbuf.append("\n");
sbuf.append("Name: javax/swing/JScrollPane.class\n");
sbuf.append("Java-Bean: True\n");
// Convert the string to a input stream
InputStream is = new ByteArrayInputStream(sbuf.toString().getBytes("UTF-8"));
// Create the manifest
manifest = new Manifest(is);
}
}
</source>
Creating an input or output stream on a ByteBuffer
<source lang="java">
import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.nio.ByteBuffer; public class Main {
public static void main(String[] argv) throws Exception {
ByteBuffer buf = ByteBuffer.allocate(10);
OutputStream os = new ByteBufferBackedOutputStream(buf);
InputStream is = new ByteBufferBackedInputStream(buf);
}
} class ByteBufferBackedInputStream extends InputStream{
ByteBuffer buf;
ByteBufferBackedInputStream( ByteBuffer buf){
this.buf = buf;
}
public synchronized int read() throws IOException {
if (!buf.hasRemaining()) {
return -1;
}
return buf.get();
}
public synchronized int read(byte[] bytes, int off, int len) throws IOException {
len = Math.min(len, buf.remaining());
buf.get(bytes, off, len);
return len;
}
} class ByteBufferBackedOutputStream extends OutputStream{
ByteBuffer buf;
ByteBufferBackedOutputStream( ByteBuffer buf){
this.buf = buf;
}
public synchronized void write(int b) throws IOException {
buf.put((byte) b);
}
public synchronized void write(byte[] bytes, int off, int len) throws IOException {
buf.put(bytes, off, len);
}
}
</source>
Deserializes an object from an input stream.
<source lang="java">
/*
* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */
import java.io.BufferedInputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.ObjectInputStream;
public class Main {
/**
* This method deserializes an object from an input stream.
*
* @param file The input file
* @return The deserialized object
* @exception IOException IOError
*/
public static Object deserializeObject(File file)
throws IOException, ClassNotFoundException {
FileInputStream fis = new FileInputStream(file);
Object object = null;
try {
ObjectInputStream ois = new ObjectInputStream(new BufferedInputStream(fis));
object = ois.readObject();
} finally {
fis.close();
}
return object;
}
}
</source>
EOLConvertingInputStream: InputStream which converts \r bytes not followed by \n and \n not preceded by \r to \r\n.
<source lang="java">
/****************************************************************
* Licensed to the Apache Software Foundation (ASF) under one * * or more contributor license agreements. See the NOTICE file * * distributed with this work for additional information * * regarding copyright ownership. The ASF licenses this file * * to you under the Apache License, Version 2.0 (the * * "License"); you may not use this file except in compliance * * with the License. You may obtain a copy of the License at * * * * http://www.apache.org/licenses/LICENSE-2.0 * * * * Unless required by applicable law or agreed to in writing, * * software distributed under the License is distributed on an * * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * * KIND, either express or implied. See the License for the * * specific language governing permissions and limitations * * under the License. * ****************************************************************/
import java.io.IOException; import java.io.InputStream; import java.io.PushbackInputStream; /**
* InputStream which converts\r* bytes not followed by\nand\nnot * preceded by\rto\r\n. */
public class EOLConvertingInputStream extends InputStream {
/** Converts single "\r" to "\r\n" */
public static final int CONVERT_CR = 1;
/** Converts single "\n" to "\r\n" */
public static final int CONVERT_LF = 2;
/** Converts single "\r" and "\n" to "\r\n" */
public static final int CONVERT_BOTH = 3;
private PushbackInputStream in = null;
private int previous = 0;
private int flags = CONVERT_BOTH;
/**
* Creates a new EOLConvertingInputStream
* instance converting bytes in the given InputStream.
* The flag CONVERT_BOTH is the default.
*
* @param in the InputStream to read from.
*/
public EOLConvertingInputStream(InputStream in) {
this(in, CONVERT_BOTH);
}
/**
* Creates a new EOLConvertingInputStream
* instance converting bytes in the given InputStream.
*
* @param in the InputStream to read from.
* @param flags one of CONVERT_CR, CONVERT_LF or
* CONVERT_BOTH.
*/
public EOLConvertingInputStream(InputStream in, int flags) {
super();
this.in = new PushbackInputStream(in, 2);
this.flags = flags;
}
/**
* Closes the underlying stream.
*
* @throws IOException on I/O errors.
*/
@Override
public void close() throws IOException {
in.close();
}
/**
* @see java.io.InputStream#read()
*/
@Override
public int read() throws IOException {
int b = in.read();
if (b == -1) {
return -1;
}
if ((flags & CONVERT_CR) != 0 && b == "\r") {
int c = in.read();
if (c != -1) {
in.unread(c);
}
if (c != "\n") {
in.unread("\n");
}
} else if ((flags & CONVERT_LF) != 0 && b == "\n" && previous != "\r") {
b = "\r";
in.unread("\n");
}
previous = b;
return b;
}
}
</source>
Minimal InputStream subclass to fetch bytes form a String
<source lang="java">
/* Copyright (c) 2001-2009, The HSQL Development Group
* All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the HSQL Development Group nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG, * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
import java.io.IOException; import java.io.InputStream; /**
* minimal InputStream subclass to fetch bytes form a String * * @author Fred Toussi (fredt@users dot sourceforge.net) * @version 1.7.0 */
public class StringInputStream extends InputStream {
protected int strOffset = 0;
protected int charOffset = 0;
protected int available;
protected String str;
public StringInputStream(String s) {
str = s;
available = s.length() * 2;
}
public int read() throws java.io.IOException {
if (available == 0) {
return -1;
}
available--;
char c = str.charAt(strOffset);
if (charOffset == 0) {
charOffset = 1;
return (c & 0x0000ff00) >> 8;
} else {
charOffset = 0;
strOffset++;
return c & 0x000000ff;
}
}
public int available() throws IOException {
return available;
}
}
</source>
Read and return the entire contents of the supplied InputStream.
<source lang="java">
/*
* JBoss DNA (http://www.jboss.org/dna) * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. Some portions may be licensed * to Red Hat, Inc. under one or more contributor license agreements. * See the AUTHORS.txt file in the distribution for a full listing of * individual contributors. * * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA * is licensed to you under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * JBoss DNA is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; /**
* @author Randall Hauch */
public class Main {
/**
* Read and return the entire contents of the supplied {@link InputStream stream}. This method always closes the stream when
* finished reading.
*
* @param stream the stream to the contents; may be null
* @return the contents, or an empty byte array if the supplied reader is null
* @throws IOException if there is an error reading the content
*/
public static byte[] readBytes( InputStream stream ) throws IOException {
if (stream == null) return new byte[] {};
byte[] buffer = new byte[1024];
ByteArrayOutputStream output = new ByteArrayOutputStream();
boolean error = false;
try {
int numRead = 0;
while ((numRead = stream.read(buffer)) > -1) {
output.write(buffer, 0, numRead);
}
} catch (IOException e) {
error = true; // this error should be thrown, even if there is an error closing stream
throw e;
} catch (RuntimeException e) {
error = true; // this error should be thrown, even if there is an error closing stream
throw e;
} finally {
try {
stream.close();
} catch (IOException e) {
if (!error) throw e;
}
}
output.flush();
return output.toByteArray();
}
}
</source>
Read and return the entire contents of the supplied InputStream. This method always closes the stream when finished reading.
<source lang="java">
/*
* JBoss DNA (http://www.jboss.org/dna) * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. Some portions may be licensed * to Red Hat, Inc. under one or more contributor license agreements. * See the AUTHORS.txt file in the distribution for a full listing of * individual contributors. * * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA * is licensed to you under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * JBoss DNA is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */
import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.Reader; /**
* @author Randall Hauch */
public class Main {
/**
* Read and return the entire contents of the supplied {@link InputStream}. This method always closes the stream when finished
* reading.
*
* @param stream the streamed contents; may be null
* @return the contents, or an empty string if the supplied stream is null
* @throws IOException if there is an error reading the content
*/
public static String read( InputStream stream ) throws IOException {
return stream == null ? "" : read(new InputStreamReader(stream));
}
/**
* Read and return the entire contents of the supplied {@link Reader}. This method always closes the reader when finished
* reading.
*
* @param reader the reader of the contents; may be null
* @return the contents, or an empty string if the supplied reader is null
* @throws IOException if there is an error reading the content
*/
public static String read( Reader reader ) throws IOException {
if (reader == null) return "";
StringBuilder sb = new StringBuilder();
boolean error = false;
try {
int numRead = 0;
char[] buffer = new char[1024];
while ((numRead = reader.read(buffer)) > -1) {
sb.append(buffer, 0, numRead);
}
} catch (IOException e) {
error = true; // this error should be thrown, even if there is an error closing reader
throw e;
} catch (RuntimeException e) {
error = true; // this error should be thrown, even if there is an error closing reader
throw e;
} finally {
try {
reader.close();
} catch (IOException e) {
if (!error) throw e;
}
}
return sb.toString();
}
}
</source>
Reads at most certain bytes from input stream and returns them as a byte array.
<source lang="java">
/*
* Copyright Aduna (http://www.aduna-software.ru/) (c) 1997-2006. * * Licensed under the Aduna BSD-style license. */
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; public class Main {
/**
* Reads at most maxBytes bytes from the supplied input stream and
* returns them as a byte array.
*
* @param in The InputStream supplying the bytes.
* @param maxBytes The maximum number of bytes to read from the input
* stream.
* @return A byte array of size maxBytes if the input stream can
* produce that amount of bytes, or a smaller byte containing all available
* bytes from the stream otherwise.
*/
public static final byte[] readBytes(InputStream in, int maxBytes)
throws IOException
{
byte[] result = new byte[maxBytes];
int bytesRead = in.read(result);
int totalBytesRead = bytesRead;
while (totalBytesRead < maxBytes && bytesRead >= 0) {
// Read more bytes
bytesRead = in.read(result, bytesRead, maxBytes - bytesRead);
if (bytesRead > 0) {
totalBytesRead += bytesRead;
}
}
if (totalBytesRead < 0) {
// InputStream at end-of-file
result = new byte[0];
}
else if (totalBytesRead < maxBytes) {
// Create smaller byte array
byte[] tmp = new byte[totalBytesRead];
System.arraycopy(result, 0, tmp, 0, totalBytesRead);
result = tmp;
}
return result;
}
}
</source>
Size Limit InputStream
<source lang="java">
/*
* Input stream wrapper with a byte limit. * Copyright (C) 2004 Stephen Ostermiller * http://ostermiller.org/contact.pl?regarding=Java+Utilities * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * See COPYING.TXT for details. */
import java.io.*; /**
* An input stream wrapper that will read only a set number of bytes from the * underlying stream. * * @author Stephen Ostermiller http://ostermiller.org/contact.pl?regarding=Java+Utilities * @since ostermillerutils 1.04.00 */
public class SizeLimitInputStream extends InputStream {
/**
* The input stream that is being protected.
* All methods should be forwarded to it,
* after checking the size that has been read.
*
* @since ostermillerutils 1.04.00
*/
protected InputStream in;
/**
* The number of bytes to read at most from this
* Stream. Read methods should
* check to ensure that bytesRead never
* exceeds maxBytesToRead.
*
* @since ostermillerutils 1.04.00
*/
protected long maxBytesToRead = 0;
/**
* The number of bytes that have been read
* from this stream. Read methods should
* check to ensure that bytesRead never
* exceeds maxBytesToRead.
*
* @since ostermillerutils 1.04.00
*/
protected long bytesRead = 0;
/**
* The number of bytes that have been read
* from this stream since mark() was called.
*
* @since ostermillerutils 1.04.00
*/
protected long bytesReadSinceMark = 0;
/**
* The number of bytes the user has request
* to have been marked for reset.
*
* @since ostermillerutils 1.04.00
*/
protected long markReadLimitBytes = -1;
/**
* Get the number of bytes actually read
* from this stream.
*
* @return number of bytes that have already been taken from this stream.
*
* @since ostermillerutils 1.04.00
*/
public long getBytesRead(){
return bytesRead;
}
/**
* Get the maximum number of bytes left to read
* before the limit (set in the constructor) is reached.
*
* @return The number of bytes that (at a maximum) are left to be taken from this stream.
*
* @since ostermillerutils 1.04.00
*/
public long getBytesLeft(){
return maxBytesToRead - bytesRead;
}
/**
* Tell whether the number of bytes specified
* in the constructor have been read yet.
*
* @return true iff the specified number of bytes have all been read.
*
* @since ostermillerutils 1.04.00
*/
public boolean allBytesRead(){
return getBytesLeft() == 0;
}
/**
* Get the number of total bytes (including bytes already read)
* that can be read from this stream (as set in the constructor).
* @return Maximum bytes that can be read until the size limit runs out
*
* @since ostermillerutils 1.04.00
*/
public long getMaxBytesToRead(){
return maxBytesToRead;
}
/**
* Create a new size limit input stream from
* another stream given a size limit.
*
* @param in The input stream.
* @param maxBytesToRead the max number of bytes to allow to be read from the underlying stream.
*
* @since ostermillerutils 1.04.00
*/
public SizeLimitInputStream(InputStream in, long maxBytesToRead){
this.in = in;
this.maxBytesToRead = maxBytesToRead;
}
/**
* {@inheritDoc}
*/
@Override public int read() throws IOException {
if (bytesRead >= maxBytesToRead){
return -1;
}
int b = in.read();
if(b != -1){
bytesRead++;
bytesReadSinceMark++;
}
return b;
}
/**
* {@inheritDoc}
*/
@Override public int read(byte[] b) throws IOException {
return this.read(b, 0, b.length);
}
/**
* {@inheritDoc}
*/
@Override public int read(byte[] b, int off, int len) throws IOException {
if (bytesRead >= maxBytesToRead){
return -1;
}
long bytesLeft = getBytesLeft();
if (len > bytesLeft){
len = (int)bytesLeft;
}
int bytesJustRead = in.read(b, off, len);
bytesRead += bytesJustRead;
bytesReadSinceMark += bytesJustRead;
return bytesJustRead;
}
/**
* {@inheritDoc}
*/
@Override public long skip(long n) throws IOException {
if (bytesRead >= maxBytesToRead){
return -1;
}
long bytesLeft = getBytesLeft();
if (n > bytesLeft){
n = bytesLeft;
}
return in.skip(n);
}
/**
* {@inheritDoc}
*/
@Override public int available() throws IOException {
int available = in.available();
long bytesLeft = getBytesLeft();
if (available > bytesLeft){
available = (int)bytesLeft;
}
return available;
}
/**
* Close this stream and underlying streams.
* Calling this method may make data on the
* underlying stream unavailable.
* <p>
* Consider wrapping this stream in a NoCloseStream
* so that clients can
* call close() with no effect.
*
* @since ostermillerutils 1.04.00
*/
@Override public void close() throws IOException {
in.close();
}
/**
* {@inheritDoc}
*/
@Override public void mark(int readlimit){
if (in.markSupported()){
markReadLimitBytes = readlimit;
bytesReadSinceMark = 0;
in.mark(readlimit);
}
}
/**
* {@inheritDoc}
*/
@Override public void reset() throws IOException {
if (in.markSupported() && bytesReadSinceMark <= markReadLimitBytes){
bytesRead -= bytesReadSinceMark;
in.reset();
bytesReadSinceMark = 0;
}
}
/**
* {@inheritDoc}
*/
@Override public boolean markSupported(){
return in.markSupported();
}
}
</source>
