Java/Development Class/Console
Версия от 18:01, 31 мая 2010; (обсуждение)
Содержание
- 1 A representation of the command line arguments passed to a Java class" main(String[]) method
- 2 Command line input
- 3 How to deal with the console parameters
- 4 How to read from standard input
- 5 Java program to calculate the area of a circle
- 6 Java program to demonstrate menu selection
- 7 Output to standard output and standard error; and input from standard input.
- 8 Processing the command line
- 9 Read an int from Standard Input
- 10 Read an int from Standard Input, using 1.5
- 11 Read input from console
- 12 Show use of Argv to get an integer value from command line
- 13 SimpleCalc -- simple calculator using 1.5 java.util.Scanner
- 14 Turn System.out into a PrintWriter
- 15 Utility class for printing aligned columns of text
- 16 VarArgsDemo - show 1.5 variable arguments
A representation of the command line arguments passed to a Java class" main(String[]) method
/*
* 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.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
*
* CommandLine is a representation of the command line arguments passed to
* a Java class" main(String[]) method. It parses the arguments for flags
* (tokens prefixed with a dash ("-")), flag-value pairs, and an ordered
* list of argument values.
*
* @author Dan Jemiolo (danj)
*
*/
public class CommandLine
{
//
// all non-flag values
//
private String[] _arguments = null;
//
// the flags (-foo) that were found on the command line
//
private Map _flags = new HashMap();
//
// the flag values that are expected to be followed with a value
// that allows the application to process the flag.
//
private Set _flagsWithValues = new HashSet();
/**
*
* @return All of the values specified on the command line that were
* not a flag or associated with a flag.
*
*/
public String[] getArguments()
{
return _arguments;
}
/**
*
* @param flagName
*
* @return The value that was specified after the flag, or null if
* the flag was not specified.
*
* @see #hasFlag(String)
*
*/
public String getFlagValue(String flagName)
{
return (String)_flags.get(flagName);
}
public int getNumberOfArguments()
{
return _arguments.length;
}
public int getNumberOfFlags()
{
return _flags.size();
}
/**
*
* @param flagName
*
* @return True if the flag was specified on the command line.
*
*/
public boolean hasFlag(String flagName)
{
return _flags.containsKey(flagName);
}
/**
*
* Reads through each argument in the given array, picking out the
* flags (and optionally,their values) from the regular arguments.
* Users should use the saveFlagValue(String) method before this one
* in order to have their command line parsed correctly.
*
* @param args
* The command line arguments given to the application.
*
*/
public void parse(String[] args)
{
List regularArgs = new ArrayList();
for (int n = 0; n < args.length; ++n)
{
if (args[n].charAt(0) == "-")
{
String name = args[n];
String value = null;
if (_flagsWithValues.contains(args[n]) &&
n < args.length - 1)
value = args[++n];
_flags.put(name, value);
}
else
regularArgs.add(args[n]);
}
int size = regularArgs.size();
_arguments = (String[])regularArgs.toArray(new String[size]);
}
/**
*
* Tells the command line parser to associate the given flag with the
* value that comes after it in the list of arguments (if the flag is
* found). This will allow the user to retrieve the flag-value pair
* later and prevent the flag value from being lumped in with the
* regular arguments.
*
* @param flagName
*
*/
public void saveFlagValue(String flagName)
{
_flagsWithValues.add(flagName);
}
}
Command line input
/*
* Copyright (c) 2000 David Flanagan. All rights reserved.
* This code is from the book Java Examples in a Nutshell, 2nd Edition.
* It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
* You may study, use, and modify it for any non-commercial purpose.
* You may distribute it non-commercially as long as you retain this notice.
* For a commercial use license, or to purchase the book (recommended),
* visit http://www.davidflanagan.ru/javaexamples2.
*/
/**
* This program prints out all its command-line arguments.
*/
public class Echo1 {
public static void main(String[] args) {
int i = 0; // Initialize the loop variable
while (i < args.length) { // Loop until the end of array
System.out.print(args[i] + " "); // Print each argument out
i++; // Increment the loop variable
}
System.out.println(); // Terminate the line
}
}
How to deal with the console parameters
public class ConsoleArguments {
public static void main(String[] args) {
if (args.length == 0) {
System.out.println("No arguments");
} else {
System.out.println("Arguments:");
for (int i = 0; i < args.length; i++) {
System.out.println(args[i]);
}
}
}
}
How to read from standard input
// : c12:Echo.java
// How to read from standard input.
// {RunByHand}
// From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002
// www.BruceEckel.ru. See copyright notice in CopyRight.txt.
import java.io.*;
public class Echo {
public static void main(String[] args) throws IOException {
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
String s;
while ((s = in.readLine()) != null && s.length() != 0)
System.out.println(s);
// An empty line or Ctrl-Z terminates the program
}
} ///:~
Java program to calculate the area of a circle
/*
Java Programming for Engineers
Julio Sanchez
Maria P. Canton
ISBN: 0849308100
Publisher: CRC Press
*/
// File name: Area.java
//Reference: Chapter 5
//
//Java program to calculate the area of a circle
//Topics:
// 1. Using numeric variables and constants
// 2. Obtaining keyboard input
// 3. Displaying program data
// 4. Performing simple numeric calculations
//
//Requires:
// 1. Keyin class in the current directory
public class Area {
// Constant PI is defined at the class level
static final double PI = 3.141592653589793;
public static void main(String[] args) {
// Local variables
double radius, area;
// Input radius from keyboard
radius = Keyin.inDouble("Enter radius: ");
// Perform calculations and display result
area = PI * (radius * radius);
System.out.println("The area is: " + area);
}
}
//**********************************************************
//**********************************************************
//Program: Keyin
//Reference: Session 20
//Topics:
// 1. Using the read() method of the ImputStream class
// in the java.io package
// 2. Developing a class for performing basic console
// input of character and numeric types
//**********************************************************
//**********************************************************
class Keyin {
//*******************************
// support methods
//*******************************
//Method to display the user"s prompt string
public static void printPrompt(String prompt) {
System.out.print(prompt + " ");
System.out.flush();
}
//Method to make sure no data is available in the
//input stream
public static void inputFlush() {
int dummy;
int bAvail;
try {
while ((System.in.available()) != 0)
dummy = System.in.read();
} catch (java.io.IOException e) {
System.out.println("Input error");
}
}
//********************************
// data input methods for
//string, int, char, and double
//********************************
public static String inString(String prompt) {
inputFlush();
printPrompt(prompt);
return inString();
}
public static String inString() {
int aChar;
String s = "";
boolean finished = false;
while (!finished) {
try {
aChar = System.in.read();
if (aChar < 0 || (char) aChar == "\n")
finished = true;
else if ((char) aChar != "\r")
s = s + (char) aChar; // Enter into string
}
catch (java.io.IOException e) {
System.out.println("Input error");
finished = true;
}
}
return s;
}
public static int inInt(String prompt) {
while (true) {
inputFlush();
printPrompt(prompt);
try {
return Integer.valueOf(inString().trim()).intValue();
}
catch (NumberFormatException e) {
System.out.println("Invalid input. Not an integer");
}
}
}
public static char inChar(String prompt) {
int aChar = 0;
inputFlush();
printPrompt(prompt);
try {
aChar = System.in.read();
}
catch (java.io.IOException e) {
System.out.println("Input error");
}
inputFlush();
return (char) aChar;
}
public static double inDouble(String prompt) {
while (true) {
inputFlush();
printPrompt(prompt);
try {
return Double.valueOf(inString().trim()).doubleValue();
}
catch (NumberFormatException e) {
System.out
.println("Invalid input. Not a floating point number");
}
}
}
}
/*
Java Programming for Engineers
Julio Sanchez
Maria P. Canton
ISBN: 0849308100
Publisher: CRC Press
*/
// File name: MenuDemo.java
//Reference: Chapter 9
//
//Java program to demonstrate menu selection
//Topics:
// 1. Using the switch construct
//
//Requires:
// 1. Keyin class in the current directory
public class ConsoleMenuDemo {
public static void main(String[] args) {
// Local variable
int swValue;
// Display menu graphics
System.out.println("============================");
System.out.println("| MENU SELECTION DEMO |");
System.out.println("============================");
System.out.println("| Options: |");
System.out.println("| 1. Option 1 |");
System.out.println("| 2. Option 2 |");
System.out.println("| 3. Exit |");
System.out.println("============================");
swValue = Keyin.inInt(" Select option: ");
// Switch construct
switch (swValue) {
case 1:
System.out.println("Option 1 selected");
break;
case 2:
System.out.println("Option 2 selected");
break;
case 3:
System.out.println("Exit selected");
break;
default:
System.out.println("Invalid selection");
break; // This break is not really necessary
}
}
}
//**********************************************************
//**********************************************************
//Program: Keyin
//Reference: Session 20
//Topics:
// 1. Using the read() method of the ImputStream class
// in the java.io package
// 2. Developing a class for performing basic console
// input of character and numeric types
//**********************************************************
//**********************************************************
class Keyin {
//*******************************
// support methods
//*******************************
//Method to display the user"s prompt string
public static void printPrompt(String prompt) {
System.out.print(prompt + " ");
System.out.flush();
}
//Method to make sure no data is available in the
//input stream
public static void inputFlush() {
int dummy;
int bAvail;
try {
while ((System.in.available()) != 0)
dummy = System.in.read();
} catch (java.io.IOException e) {
System.out.println("Input error");
}
}
//********************************
// data input methods for
//string, int, char, and double
//********************************
public static String inString(String prompt) {
inputFlush();
printPrompt(prompt);
return inString();
}
public static String inString() {
int aChar;
String s = "";
boolean finished = false;
while (!finished) {
try {
aChar = System.in.read();
if (aChar < 0 || (char) aChar == "\n")
finished = true;
else if ((char) aChar != "\r")
s = s + (char) aChar; // Enter into string
}
catch (java.io.IOException e) {
System.out.println("Input error");
finished = true;
}
}
return s;
}
public static int inInt(String prompt) {
while (true) {
inputFlush();
printPrompt(prompt);
try {
return Integer.valueOf(inString().trim()).intValue();
}
catch (NumberFormatException e) {
System.out.println("Invalid input. Not an integer");
}
}
}
public static char inChar(String prompt) {
int aChar = 0;
inputFlush();
printPrompt(prompt);
try {
aChar = System.in.read();
}
catch (java.io.IOException e) {
System.out.println("Input error");
}
inputFlush();
return (char) aChar;
}
public static double inDouble(String prompt) {
while (true) {
inputFlush();
printPrompt(prompt);
try {
return Double.valueOf(inString().trim()).doubleValue();
}
catch (NumberFormatException e) {
System.out
.println("Invalid input. Not a floating point number");
}
}
}
}
Output to standard output and standard error; and input from standard input.
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class InputOutputDemoStandardInputOutput {
public static void main(String[] a) throws Exception {
//Write characters to standard output and standard error:
System.out.println("std output");
System.err.println("std error");
//Read characters from standard input (the keyboard):
System.out.print("Type some characters and press Enter: ");
BufferedReader bisr = new BufferedReader(new InputStreamReader(
System.in));
String response = bisr.readLine();
System.out.println("You typed: "" + response + """);
//Read a byte from standard input (the keyboard):
System.out.print("Type one character and press Enter: ");
byte b = (byte) System.in.read();
System.out.println("First byte of your input is: " + b);
}
}
Processing the command line
/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
* statements and notices. Redistributions must also contain a
* copy of this document.
*
* 2. 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.
*
* 3. The name "Exolab" must not be used to endorse or promote
* products derived from this Software without prior written
* permission of Exoffice Technologies. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Exoffice Technologies. Exolab is a registered
* trademark of Exoffice Technologies.
*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
* ``AS IS"" AND ANY EXPRESSED 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
* EXOFFICE TECHNOLOGIES OR ITS 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.
*
* Copyright 1999 (C) Exoffice Technologies Inc. All Rights Reserved.
*
* $Id: CommandLine.java,v 1.1 2004/11/26 01:51:02 tanderson Exp $
*
* Date Author Changes
* 1/6/2000 jima Created
* 1/9/2000 jima changed package name from com.ruware to org.exolab
* 7/1/2000 jima removed the CW prefix from the class name
* 1/8/2001 jima Removed it from jtf library and imported it into
* the openjms library
*/
import java.util.Hashtable;
import java.util.Vector;
/**
* This core class is responsible for processing the command line and
* storing away the list of options and parameters specified. The
* difference between an option and a command line is that an option
* is a boolean value (true if it is specified and false otherwise)
* and a parameter always has an associated value.
*
* @version $version$
* @author jima
**/
public class CommandLine {
/**
* A list of option of switches on the command line. A switch
* is either set or not
*/
private Vector _switches = new Vector();
/**
* A dictionary of all the options and their associated values
*/
private Hashtable _options = new Hashtable();
/**
* Construct an instance of this class with the specified string
* array.
*
* @param args command line argument
*/
public CommandLine(String[] args) {
processCommandLine(args);
}
/**
* Default constructor which simply initialised the class
*/
public CommandLine() {
}
/**
* Check if the following option or command has been specified
*
* @param name name of option or command
* @return boolean true if it has been specified
*/
public boolean exists(String name) {
return _switches.contains(name) || _options.containsKey(name);
}
/**
* Check if the following option has been specified.
*
* @param name name of the option
* @return boolean true if it has been specified
*/
public boolean isSwitch(String name) {
return _switches.contains(name);
}
/**
* Check if the following parameter has been specified.
*
* @param name name of the parameter
* @return boolean true if it has been specified
*/
public boolean isParameter(String name) {
return _options.containsKey(name);
}
/**
* Return the value of the parameter or option. If the string nominates
* an option then return null
*
* @param name name of option or parameter
* @return String value of parameter or null
*/
public String value(String name) {
String result = null;
if (_options.containsKey(name)) {
result = (String) _options.get(name);
}
return result;
}
/**
* Return the value of the parameter or option, returning a default
* value if none is specified
*
* @param name name of option or parameter
* @param defaultValue the default value
* @return String value of parameter
*/
public String value(String name, String defaultValue) {
String result = value(name);
return (result != null) ? result : defaultValue;
}
/**
* Add the following option or parameter to the list. An option will
* have a null value, whereas a parameter will have a non-null value.
* <p>
* This will automatically overwrite the previous value, if one has been
* specified.
*
* @param name name of option or parameter
* @param value value of name
* @return boolean true if it was successfully added
*/
public boolean add(String name, String value) {
return add(name, value, true);
}
/**
* Add the following option or parameter to the list. An option will
* have a null value, whereas a parameter will have a non-null value.
* <p>
* If the overwrite flag is true then this value will overwrite the
* previous value. If the overwrite flag is false and the name already
* exists then it will not overwrite it and the function will return
* false. In all other circumstances it will return true.
*
* @param name name of option or parameter
* @param value value of name
* @param overwrite true to overwrite previous value
* @return boolean true if it was successfully added
*/
public boolean add(String name, String value, boolean overwrite) {
boolean result = false;
if (value == null) {
// it is an option
if ((_switches.contains(name)) &&
(overwrite)) {
_switches.addElement(name);
result = true;
} else if (!_switches.contains(name)) {
_switches.addElement(name);
result = true;
}
} else {
// parameter
if ((_options.containsKey(name)) &&
(overwrite)) {
_options.put(name, value);
result = true;
} else if (!_options.containsKey(name)) {
_options.put(name, value);
result = true;
}
}
return result;
}
/**
* This method processes the command line and extracts the list of
* options and command lines. It doesn"t intepret the meaning of the
* entities, which is left to the application.
*
* @param args command line as a collection of tokens
*/
private void processCommandLine(String[] args) {
boolean prev_was_hyphen = false;
String prev_key = null;
for (int index = 0; index < args.length; index++) {
if (args[index].startsWith("-")) {
// if the previous string started with a hyphen then
// it was an option store store it, without the hyphen
// in the _switches vector. Otherwise if the previous was
// not a hyphen then store key and value in the _options
// hashtable
if (prev_was_hyphen) {
add(prev_key, null);
}
prev_key = args[index].substring(1);
prev_was_hyphen = true;
// check to see whether it is the last element in the
// arg list. If it is then assume it is an option and
// break the processing
if (index == args.length - 1) {
add(prev_key, null);
break;
}
} else {
// it does not start with a hyphen. If the prev_key is
// not null then set the value to the prev_value.
if (prev_key != null) {
add(prev_key, args[index]);
prev_key = null;
}
prev_was_hyphen = false;
}
}
}
}
Read an int from Standard Input
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
import java.io.*;
/**
* Read an int from Standard Input
* @author Ian F. Darwin, http://www.darwinsys.ru/
* @version $Id: ReadStdinInt.java,v 1.2 2004/02/08 23:57:29 ian Exp $
*/
public class ReadStdinInt {
public static void main(String[] ap) {
String line = null;
int val = 0;
try {
BufferedReader is = new BufferedReader(
new InputStreamReader(System.in));
line = is.readLine();
val = Integer.parseInt(line);
} catch (NumberFormatException ex) {
System.err.println("Not a valid number: " + line);
} catch (IOException e) {
System.err.println("Unexpected IO ERROR: " + e);
}
System.out.println("I read this number: " + val);
}
}
Read an int from Standard Input, using 1.5
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
import java.util.Scanner;
/**
* Read an int from Standard Input, using 1.5
* @author Ian F. Darwin, http://www.darwinsys.ru/
* @version $Id: ReadStdinInt15.java,v 1.2 2004/03/07 16:31:58 ian Exp $
*/
public class ReadStdinInt15 {
public static void main(String[] ap) {
int val;
try {
Scanner sc = Scanner.create(System.in); // Requires J2SE 1.5
val = sc.nextInt();
} catch (NumberFormatException ex) {
System.err.println("Not a valid number: " + ex);
return;
}
System.out.println("I read this number: " + val);
}
}
Read input from console
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.DecimalFormat;
import java.text.ParseException;
public class ReadDoubleFromConsole {
public static void main(String[] args) {
System.out.println("Enter a number.");
double numberFromConsole;
try {
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
String s = br.readLine();
DecimalFormat df = new DecimalFormat();
Number n = df.parse(s);
numberFromConsole = n.doubleValue();
} catch (IOException e) {
numberFromConsole = 0;
} catch (ParseException e) {
numberFromConsole = 0;
}
System.out.println(numberFromConsole );
}
}
Show use of Argv to get an integer value from command line
/** Show use of Argv to get an integer value from command line */
public class AddException {
/** Main program */
public static void main(String[] argv) {
int number = 0;
System.out.println("The number of words in argv is " + argv.length);
if (argv.length == 0) {
number = 1234;
} else if (argv.length == 1) {
try {
number = Integer.parseInt(argv[0]);
} catch(NumberFormatException e) {
System.err.println("Number " + argv[0] + " invalid (" + e.getMessage() + ").");
System.exit(1);
}
} else {
System.err.println("usage: UseArgv number");
System.exit(1);
}
System.out.println("OK, number is " + number);
}
}
SimpleCalc -- simple calculator using 1.5 java.util.Scanner
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.util.Scanner;
import java.util.Stack;
/**
* SimpleCalc -- simple calculator using 1.5 java.util.Scanner
* @version $Id: SimpleCalcScanner.java,v 1.3 2004/03/10 18:01:35 ian Exp $
*/
public class SimpleCalcScanner {
/** The Scanner */
protected Scanner scan;
/** The output */
protected PrintWriter out = new PrintWriter(System.out);
/** The variable name (not used in this version) */
protected String variable;
/** The operand stack */
protected Stack s = new Stack();
/* Driver - main program */
public static void main(String[] av) throws IOException {
if (av.length == 0)
new SimpleCalcScanner(
new InputStreamReader(System.in)).doCalc();
else
for (int i=0; i<av.length; i++)
new SimpleCalcScanner(av[i]).doCalc();
}
/** Construct a SimpleCalcScanner by name */
public SimpleCalcScanner(String fileName) throws IOException {
this(new FileReader(fileName));
}
/** Construct a SimpleCalcScanner from an open Reader */
public SimpleCalcScanner(Reader rdr) throws IOException {
scan = new Scanner(rdr);
// Control the input character set:
scan.slashSlashComments(true); // treat "//" as comments
scan.ordinaryChar("-"); // used for subtraction
scan.ordinaryChar("/"); // used for division
}
/** Construct a SimpleCalcScanner from a Reader and a PrintWriter */
public SimpleCalcScanner(Reader rdr, PrintWriter pw) throws IOException {
this(rdr);
setWriter(pw);
}
/** Change the output to go to a new PrintWriter */
public void setWriter(PrintWriter pw) {
out = pw;
}
protected void doCalc() throws IOException {
int iType;
double tmp;
while (scan.hasNext()) {
if (scan.hasNextDouble()) {
push(scan.nextDouble());
} else {
String token = scan.next().toString();
if (token.equals("+")) {
// Found + operator, perform it immediately.
push(pop() + pop());
} else if (token.equals("-")) {
// Found - operator, perform it (order matters).
tmp = pop();
push(pop() - tmp);
} else if (token.equals("*")) {
// Multiply is commutative
push(pop() * pop());
} else if (token.equals("/")) {
// Handle division carefully: order matters!
tmp = pop();
push(pop() / tmp);
} else if (token.equals("=")) {
out.println(peek());
} else {
out.println("What"s this? " + token);
}
}
}
}
void push(double val) {
s.push(new Double(val));
}
double pop() {
return ((Double)s.pop()).doubleValue();
}
double peek() {
return ((Double)s.peek()).doubleValue();
}
void clearStack() {
s.removeAllElements();
}
}
Turn System.out into a PrintWriter
// : c12:ChangeSystemOut.java
// Turn System.out into a PrintWriter.
// From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002
// www.BruceEckel.ru. See copyright notice in CopyRight.txt.
import java.io.PrintWriter;
public class ChangeSystemOut {
public static void main(String[] args) {
PrintWriter out = new PrintWriter(System.out, true);
out.println("Hello, world");
}
} ///:~
Utility class for printing aligned columns of text
/*
* @(#)VMMetrics.java 1.3 04/01/05
*
* Copyright (c) 2000-2003 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* modify and redistribute this software in source and binary code form,
* provided that i) this copyright notice and license appear on all copies of
* the software; and ii) Licensee does not utilize the software in a manner
* which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
* NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
* LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
* LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
* OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control of
* aircraft, air traffic, aircraft navigation or aircraft communications; or in
* the design, construction, operation or maintenance of any nuclear
* facility. Licensee represents and warrants that it will not use or
* redistribute the Software for such purposes.
*/
/*
* @(#)MultiColumnPrinter.java 1.3 04/09/15
*
* Copyright 2003 Sun Microsystems, Inc. All Rights Reserved
* SUN PROPRIETARY/CONFIDENTIAL
* Use is subject to license terms.
*
*/
import java.util.Enumeration;
import java.util.Vector;
import java.util.Map;
import java.util.TreeMap;
import java.util.Iterator;
/**
* Utility class for printing aligned collumns of text. How/where
* the text is printed is determined by the abstract methods
* doPrint(String) and doPrintln(String). The typical case is to
* create a subclass and make these methods print the string to standard
* out or error.
* <P>
* This class allows you to specify:
* <UL>
* <LI>The number of collumns in the output. This will determine
* the dimension of the string arrays passed to add(String[])
* or addTitle(String[]).
* <LI>spacing/gap between columns
* <LI>character to use for title border (null means no border)
* <LI>column alignment. Only LEFT/CENTER is supported for now.
* </UL>
*
* <P>
* Example usage:
* <PRE>
* MyPrinter mp = new MyPrinter(3, 2, "-");
* String oneRow[] = new String [ 3 ];
* oneRow[0] = "User Name";
* oneRow[1] = "Email Address";
* oneRow[2] = "Phone Number";
* mp.addTitle(oneRow);
*
* oneRow[0] = "Bob";
* oneRow[1] = "bob@foo.ru";
* oneRow[2] = "123-4567";
* mp.add(oneRow);
*
* oneRow[0] = "John";
* oneRow[1] = "john@foo.ru";
* oneRow[2] = "456-7890";
* mp.add(oneRow);
* mp.print();
* </PRE>
*
* <P>
* The above would print:
* <P>
* <PRE>
* --------------------------------------
* User Name Email Address Phone Number
* --------------------------------------
* Bob bob@foo.ru 123-4567
* John john@foo.ru 456-7890
* </PRE>
*
*<P>
* This class also supports multi-row titles and having title
* strings spanning multiple collumns. Example usage:
* <PRE>
* TestPrinter tp = new TestPrinter(4, 2, "-");
* String oneRow[] = new String [ 4 ];
* int[] span = new int[ 4 ];
*
* span[0] = 2; // spans 2 collumns
* span[1] = 0; // spans 0 collumns
* span[2] = 2; // spans 2 collumns
* span[3] = 0; // spans 0 collumns
*
* tp.setTitleAlign(CENTER);
* oneRow[0] = "Name";
* oneRow[1] = "";
* oneRow[2] = "Contact";
* oneRow[3] = "";
* tp.addTitle(oneRow, span);
*
* oneRow[0] = "First";
* oneRow[1] = "Last";
* oneRow[2] = "Email";
* oneRow[3] = "Phone";
* tp.addTitle(oneRow);
*
* oneRow[0] = "Bob";
* oneRow[1] = "Jones";
* oneRow[2] = "bob@foo.ru";
* oneRow[3] = "123-4567";
* tp.add(oneRow);
*
* oneRow[0] = "John";
* oneRow[1] = "Doe";
* oneRow[2] = "john@foo.ru";
* oneRow[3] = "456-7890";
* tp.add(oneRow);
*
* tp.println();
* </PRE>
*
* <P>
* The above would print:
* <P>
* <PRE>
* ------------------------------------
* Name Contact
* First Last Email Phone
* ------------------------------------
* Bob Jones bob@foo.ru 123-4567
* John Doe john@foo.ru 456-7890
* </PRE>
*
*/
public abstract class MultiColumnPrinter {
final public static int LEFT = 0;
final public static int CENTER = 1;
/*
* Sets the default sorting behavior.
* When set to true, the table entries are sorted unless otherwise
* specified in a constructor.
*/
final private static boolean DEFAULT_SORT = true;
private int numCol = 2;
private int gap = 4;
private int align = CENTER;
private int titleAlign = CENTER;
private String border = null;
private Vector table = null;
private Vector titleTable = null;
private Vector titleSpanTable = null;
private int curLength[];
private boolean sortNeeded = DEFAULT_SORT;
private int[] keyCriteria = null;
/**
* Creates a new MultiColumnPrinter class.
*
* @param numCol number of columns
* @param gap gap between each column
* @param border character used to frame the titles
* @param align type of alignment within columns
* @param sort true if the output is sorted; false otherwise
*
* REVISIT: Possibly adding another argument that specifies which ones can
* be truncated (xxx...)
*/
public MultiColumnPrinter(int numCol, int gap, String border,
int align, boolean sort) {
table = new Vector();
titleTable = new Vector();
titleSpanTable = new Vector();
curLength = new int[numCol];
this.numCol = numCol;
this.gap = gap;
this.border = border;
this.align = align;
this.titleAlign = LEFT;
this.sortNeeded = sort;
}
/**
* Creates a new sorted MultiColumnPrinter class.
*
* @param numCol number of columns
* @param gap gap between each column
* @param border character used to frame the titles
* @param align type of alignment within columns
*/
public MultiColumnPrinter(int numCol, int gap, String border, int align) {
this(numCol, gap, border, align, DEFAULT_SORT);
}
/**
* Creates a sorted new MultiColumnPrinter class using LEFT alignment.
*
* @param numCol number of columns
* @param gap gap between each column
* @param border character used to frame the titles
*/
public MultiColumnPrinter(int numCol, int gap, String border) {
this(numCol, gap, border, LEFT);
}
/**
* Creates a sorted new MultiColumnPrinter class using LEFT alignment
* and with no title border.
*
* @param numCol number of columns
* @param gap gap between each column
*/
public MultiColumnPrinter(int numCol, int gap) {
this(numCol, gap, null, LEFT);
}
/**
* Adds to the row of strings to be used as the title for the table.
*
* @param row Array of strings to print in one row of title.
*/
public void addTitle(String[] row) {
if (row == null)
return;
int[] span = new int [ row.length ];
for (int i = 0; i < row.length; i++) {
span[i] = 1;
}
addTitle(row, span);
}
/**
* Adds to the row of strings to be used as the title for the table.
* Also allows for certain title strings to span multiple collumns
* The span parameter is an array of integers which indicate how
* many collumns the corresponding title string will occupy.
* For a row that is 4 collumns wide, it is possible to have some
* title strings in a row to "span" multiple collumns:
*
* <P>
* <PRE>
* ------------------------------------
* Name Contact
* First Last Email Phone
* ------------------------------------
* Bob Jones bob@foo.ru 123-4567
* John Doe john@foo.ru 456-7890
* </PRE>
*
* In the example above, the title row has a string "Name" that
* spans 2 collumns. The string "Contact" also spans 2 collumns.
* The above is done by passing in to addTitle() an array that
* contains:
*
* <PRE>
* span[0] = 2; // spans 2 collumns
* span[1] = 0; // spans 0 collumns, ignore
* span[2] = 2; // spans 2 collumns
* span[3] = 0; // spans 0 collumns, ignore
* </PRE>
* <P>
* A span value of 1 is the default.
* The method addTitle(String[] row) basically does:
*
* <PRE>
* int[] span = new int [ row.length ];
* for (int i = 0; i < row.length; i++) {
* span[i] = 1;
* }
* addTitle(row, span);
* </PRE>
*
* @param row Array of strings to print in one row of title.
* @param span Array of integers that reflect the number of collumns
* the corresponding title string will occupy.
*/
public void addTitle(String[] row, int span[]) {
// Need to create a new instance of it, otherwise the new values will
// always overwrite the old values.
String[] rowInstance = new String[(row.length)];
for (int i = 0; i < row.length; i++) {
rowInstance[i] = row[i];
}
titleTable.addElement(rowInstance);
titleSpanTable.addElement(span);
}
/**
* Set alignment for title strings
*
* @param titleAlign
*/
public void setTitleAlign(int titleAlign) {
this.titleAlign = titleAlign;
}
/**
* Adds one row of text to output.
*
* @param row Array of strings to print in one row.
*/
public void add(String[] row) {
// Need to create a new instance of it, otherwise the new values will
// always overwrite the old values.
String[] rowInstance = new String[(row.length)];
for (int i = 0; i < row.length; i++) {
rowInstance[i] = row[i];
}
table.addElement(rowInstance);
}
/**
* Clears title strings.
*/
public void clearTitle() {
titleTable.clear();
titleSpanTable.clear();
}
/**
* Clears strings.
*/
public void clear() {
table.clear();
if (curLength != null) {
for (int i = 0; i < curLength.length; ++i) {
curLength[i] = 0;
}
}
}
/**
* Prints the multi-column table, including the title.
*/
public void print() {
print(true);
}
/**
* Prints the multi-column table.
*
* @param printTitle Specifies if the title rows should be printed.
*/
public void print(boolean printTitle) {
// REVISIT:
// Make sure you take care of curLength and row being null value cases.
// Get the longest string for each column and store in curLength[]
// Scan through title rows
Enumeration elm = titleTable.elements();
Enumeration spanEnum = titleSpanTable.elements();
int rowNum = 0;
while (elm.hasMoreElements()) {
String[] row = (String[])elm.nextElement();
int[] curSpan = (int[])spanEnum.nextElement();
for (int i = 0; i < numCol; i++) {
// Fix for 4627901: NullPtrException seen when
// execute "jmqcmd list dur"
// This happens when a field to be listed is null.
// None of the fields should be null, but if it
// happens to be so, replace it with "-".
if (row[i] == null)
row[i] = "-";
int len = row[i].length();
/*
* If a title string spans multiple collumns, then
* the space it occupies in each collumn is at most
* len/span (since we have gap to take into account
* as well).
*/
int span = curSpan[i], rem = 0;
if (span > 1) {
rem = len % span;
len = len/span;
}
if (curLength[i] < len) {
curLength[i] = len;
if ((span > 1) && ((i+span) <= numCol)) {
for (int j=i+1; j<(i+span); ++j) {
curLength[j] = len;
}
/*
* Add remainder to last collumn in span
* to avoid round-off errors.
*/
curLength[(i+span)-1] += rem;
}
}
}
++rowNum;
}
// Scan through rest of rows
elm = table.elements();
while (elm.hasMoreElements()) {
String[] row = (String[])elm.nextElement();
for (int i = 0; i < numCol; i++) {
// Fix for 4627901: NullPtrException seen when
// execute "jmqcmd list dur"
// This happens when a field to be listed is null.
// None of the fields should be null, but if it
// happens to be so, replace it with "-".
if (row[i] == null)
row[i] = "-";
if (curLength[i] < row[i].length())
curLength[i] = row[i].length();
}
}
/*
* Print title
*/
if (printTitle) {
printBorder();
elm = titleTable.elements();
spanEnum = titleSpanTable.elements();
while (elm.hasMoreElements()) {
String[] row = (String[])elm.nextElement();
int[] curSpan = (int[])spanEnum.nextElement();
for (int i = 0; i < numCol; i++) {
int availableSpace = 0, span = curSpan[i];
if (span == 0)
continue;
availableSpace = curLength[i];
if ((span > 1) && ((i+span) <= numCol)) {
for (int j=i+1; j<(i+span); ++j) {
availableSpace += gap;
availableSpace += curLength[j];
}
}
if (titleAlign == CENTER) {
int space_before, space_after;
space_before = (availableSpace-row[i].length())/2;
space_after = availableSpace-row[i].length() - space_before;
printSpaces(space_before);
doPrint(row[i]);
printSpaces(space_after);
if (i < numCol-1) printSpaces(gap);
} else {
doPrint(row[i]);
if (i < numCol-1) printSpaces(availableSpace-row[i].length()+gap);
}
}
doPrintln("");
}
printBorder();
}
if (sortNeeded)
printSortedTable();
else
printUnsortedTable();
}
/*
* Prints the table entries in the sorted order.
*/
private void printSortedTable() {
// Sort the table entries
TreeMap sortedTable = new TreeMap();
Enumeration elm = table.elements();
while (elm.hasMoreElements()) {
String[] row = (String[])elm.nextElement();
// If keyCriteria contains valid info use that
// to create the key; otherwise, use the default row[0]
// for the key.
if (keyCriteria != null && keyCriteria.length > 0) {
String key = getKey(row);
if (key != null)
sortedTable.put(key, row);
else
sortedTable.put(row[0], row);
} else {
sortedTable.put(row[0], row);
}
}
// Iterate through the table entries
Iterator iterator = sortedTable.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry entry = (Map.Entry)iterator.next();
String[] row = ((String[])entry.getValue());
printRow(row);
}
}
/*
* Creates the key for the current row based on the
* criteria specified by setKeyCriteria().
* If key cannot be created by the criteria, it simply returns
* null.
*
* Examples:
* String[] row = {"foo", "bar", "hello");
*
* int[] keyCriteria = {0};
* key = "foo";
*
* int[] keyCriteria = {0, 1};
* key = "foobar";
*
* int[] keyCriteria = {2, 1};
* key = "hellobar";
*
* int[] keyCriteria = {4};
* key = null;
*/
private String getKey(String[] row) {
String key = "";
for (int i = 0; i < keyCriteria.length; i++) {
int content = keyCriteria[i];
try {
key = key + row[content];
} catch (ArrayIndexOutOfBoundsException ae) {
// Happens when keyCriteria[] contains an index that
// does not exist in "row".
return null;
}
}
return key;
}
/*
* Prints the table entries in the order they were entered.
*/
private void printUnsortedTable() {
Enumeration elm = table.elements();
while (elm.hasMoreElements()) {
String[] row = (String[])elm.nextElement();
printRow(row);
}
}
private void printRow(String[] row) {
for (int i = 0; i < numCol; i++) {
if (align == CENTER) {
int space1, space2;
space1 = (curLength[i]-row[i].length())/2;
space2 = curLength[i]-row[i].length() - space1;
printSpaces(space1);
doPrint(row[i]);
printSpaces(space2);
if (i < numCol-1) printSpaces(gap);
} else {
doPrint(row[i]);
if (i < numCol-1) printSpaces(curLength[i]-row[i].length()+gap);
}
}
doPrintln("");
}
/**
* Prints the multi-column table, with a carriage return.
*/
public void println() {
print();
doPrintln("");
}
private void printSpaces(int count) {
for (int i = 0; i < count; ++i) {
doPrint(" ");
}
}
private void printBorder() {
int colNum = 1;
if (border == null) return;
// For the value in each column
for (int i = 0; i < numCol; i++) {
for (int j = 0; j < curLength[i]; j++) {
doPrint(border);
}
}
// For the gap between each column
for (int i = 0; i < numCol-1; i++) {
for (int j = 0; j < gap; j++) {
doPrint(border);
}
}
doPrintln("");
}
/*
* Sets the criteria for the key.
* new int[] {0, 1} means use the first and the second
* elements of the array.
*/
public void setKeyCriteria(int[] criteria) {
this.keyCriteria = criteria;
}
/**
* Method that does the actual printing. Override this method to
* print to your destination of choice (stdout, stream, etc).
*
* @param str String to print.
*/
public abstract void doPrint(String str);
/**
* Method that does the actual printing. Override this method to
* print to your destination of choice (stdout, stream, etc).
*
* This method also prints a newline at the end of the string.
*
* @param str String to print.
*/
public abstract void doPrintln(String str);
}
VarArgsDemo - show 1.5 variable arguments
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
import java.io.PrintStream;
import java.util.Date;
/**
* VarArgsDemo - show 1.5 variable arguments
*
* @author ian
* @version $Id: VarArgsDemo.java,v 1.1 2004/03/07 16:35:13 ian Exp $
*/
public class VarArgsDemo {
public static void main(String[] args) {
process(System.out, "Hello", "Goodbye");
process(System.out, 42, 1066, 1776);
process(System.out, "Foo", new Date(), new Object());
}
static void process(PrintStream out, Object ... args) {
line();
for (int i = 0; i < args.length; i++){
out.println("Argument " + i + " is " + args[i]);
}
}
static void process(PrintStream out, int ... args) {
for (int i = 0; i < args.length; i++){
out.println("Argument " + i + " is " + args[i]);
}
}
private static void line() {
System.out.println("--------------------------");
}
}
