Java/File Input Output/FileWriter
Содержание
BufferedWriter out of FileWriter
<source lang="java">
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. 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 Sun Microsystems 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 THE COPYRIGHT OWNER 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.BufferedReader; import java.io.BufferedWriter; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; public class BufferedCopy {
public static void main(String[] args) throws IOException {
BufferedReader inputStream = null;
BufferedWriter outputStream = null;
try {
inputStream = new BufferedReader(new FileReader("xanadu.txt"));
outputStream = new BufferedWriter(new FileWriter("characteroutput.txt"));
int c;
while ((c = inputStream.read()) != -1) {
outputStream.write(c);
}
} finally {
if (inputStream != null) {
inputStream.close();
}
if (outputStream != null) {
outputStream.close();
}
}
}
}
</source>
Copy Characters between FileReader and FileWriter
<source lang="java">
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. 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 Sun Microsystems 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 THE COPYRIGHT OWNER 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.FileReader; import java.io.FileWriter; import java.io.IOException; public class CopyCharacters {
public static void main(String[] args) throws IOException {
FileReader inputStream = null;
FileWriter outputStream = null;
try {
inputStream = new FileReader("xanadu.txt");
outputStream = new FileWriter("characteroutput.txt");
int c;
while ((c = inputStream.read()) != -1) {
outputStream.write(c);
}
} finally {
if (inputStream != null) {
inputStream.close();
}
if (outputStream != null) {
outputStream.close();
}
}
}
}
</source>
Copy file character by character with FileReader and FileWriter
<source lang="java">
import java.io.FileReader; import java.io.FileWriter; class FileCopy {
public static void main(String args[]) throws Exception {
FileReader fr = new FileReader(args[0]);
// Create a file writer
FileWriter fw = new FileWriter(args[1]);
// Read and copy characters
int i;
while ((i = fr.read()) != -1) {
fw.write(i);
}
fw.close();
fr.close();
}
}
</source>
extends FilterWriter and extends FilterReader
<source lang="java">
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. 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 Sun Microsystems 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 THE COPYRIGHT OWNER 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.FileReader; import java.io.FileWriter; import java.io.FilterReader; import java.io.FilterWriter; import java.io.IOException; import java.io.Reader; import java.io.Writer; public class CounterDemo {
public static void main(String[] args) throws IOException {
CountReader cr = new CountReader(new FileReader("xanadu.txt"), "e");
CountWriter cw = new CountWriter(new FileWriter("outagain.txt"), "e");
int c = 0;
while ((c = cr.read()) != -1) {
cw.write(c);
}
System.out.println(cr.getCount());
System.out.println(cw.getCount());
cr.close();
cw.close();
}
} /*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. 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 Sun Microsystems 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 THE COPYRIGHT OWNER 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. */
class CountWriter extends FilterWriter {
private int count = 0;
private char lookFor = 0;
public CountWriter(Writer in, char lookFor) {
super(in);
this.lookFor = lookFor;
}
public void write(int character) throws IOException {
super.write(character);
if ((char) character == lookFor) {
count++;
}
}
public void write(char[] cbuf) throws IOException {
super.write(cbuf);
int length = cbuf.length;
for (int i = 0; i < length; i++) {
if (cbuf[i] == lookFor) {
count++;
}
}
}
public void write(char[] cbuf, int off, int len) throws IOException {
super.write(cbuf, off, len);
int length = cbuf.length;
for (int i = 0; i < length; i++) {
if (cbuf[i] == lookFor) {
count++;
}
}
}
public void write(String str) throws IOException {
super.write(str);
int length = str.length();
for (int i = 0; i < length; i++) {
if (str.charAt(i) == lookFor) {
count++;
}
}
}
public void write(String str, int off, int len) throws IOException {
super.write(str, off, len);
int length = str.length();
for (int i = 0; i < length; i++) {
if (str.charAt(i) == lookFor) {
count++;
}
}
}
public int getCount() {
return count;
}
} /*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. 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 Sun Microsystems 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 THE COPYRIGHT OWNER 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. */
class CountReader extends FilterReader {
private int count = 0;
private char lookFor = 0;
public CountReader(Reader in, char lookFor) {
super(in);
this.lookFor = lookFor;
}
public int read() throws IOException {
int character = super.read();
if ((char) character == lookFor) {
count++;
}
return character;
}
public int read(char[] cbuf) throws IOException {
int numChars = super.read(cbuf);
int length = cbuf.length;
for (int i = 0; i < length; i++) {
if (cbuf[i] == lookFor) {
count++;
}
}
return numChars;
}
public int read(char[] cbuf, int off, int len) throws IOException {
int numChars = super.read(cbuf, off, len);
int length = cbuf.length;
for (int i = 0; i < length; i++) {
if (cbuf[i] == lookFor) {
count++;
}
}
return numChars;
}
public void reset() throws IOException {
super.reset();
count = 0;
}
public boolean markSupported() {
return false;
}
public void mark(int readAheadLimit) throws IOException {
throw new IOException("CountReader does not support the mark() operation.");
}
public int getCount() {
return count;
}
}
</source>
Write string to file with FileWriter
<source lang="java">
import java.io.FileWriter; class FileWriterDemo {
public static void main(String args[]) throws Exception {
FileWriter fw = new FileWriter(args[0]);
// Write strings to the file
for (int i = 0; i < 12; i++) {
fw.write("Line " + i + "\n");
}
// Close file writer
fw.close();
}
}
</source>
