上次写字符串MD5值计算器之后没多久写的。现在把代码贴上吧。
基本和前面的字符串MD5计算器一致，只对其作了小量修改。
代码如下：
界面及按钮相关功能：
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class MainPanel extends JFrame{
File file;
private String inString;
private String compareString;
private String outputString;
static JTextField inputText = new JTextField();
static JTextField outputText = new JTextField();
static JTextField compareText = new JTextField();
static JButton fileChoose = new JButton("打开文件");
static JButton compare = new JButton("比较");
static JButton empty = new JButton("清空");
static JButton freeback = new JButton("意见反馈");
// create main user interface
MainPanel() {
super("MD5校验器 V0.1");
setSize(320, 160);
setResizable(false);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
NewAction newAction = new NewAction();
JPanel jp = new JPanel();
jp.setLayout(new BorderLayout());
JPanel labels = new JPanel();
labels.setLayout(new GridLayout(3, 1));
labels.add(new JLabel(" 文件选择"));
labels.add(new JLabel(" MD5值 "));
labels.add(new JLabel(" 参考值 "));
JPanel texts = new JPanel();
GridLayout textLayout = new GridLayout(3, 1);
textLayout.setVgap(5);
texts.setLayout(textLayout);
inputText.setEditable(false);
outputText.setEditable(false);
texts.add(inputText);
texts.add(outputText);
texts.add(compareText);
JPanel buttons = new JPanel();
/*
FlowLayout buttonsLay = new FlowLayout();
buttonsLay.setHgap(5);
buttons.setLayout(buttonsLay);
*/
fileChoose.addActionListener(newAction);
compare.addActionListener(newAction);
empty.addActionListener(newAction);
freeback.addActionListener(newAction);
buttons.add(fileChoose);
buttons.add(compare);
buttons.add(empty);
buttons.add(freeback);
jp.add(labels, BorderLayout.WEST);
jp.add(texts, BorderLayout.CENTER);
jp.add(buttons, BorderLayout.SOUTH);
setContentPane(jp);
}
public static void main(String[] args) {
MainPanel panel = new MainPanel();
panel.setVisible(true);
}
// implements functions of buttons
class NewAction implements ActionListener {
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
JButton button = (JButton) e.getSource();
if ( button == fileChoose) { // 文件选择
JFileChooser chooser = new JFileChooser();
int returnVal = chooser.showOpenDialog(fileChoose);
if ( JFileChooser.APPROVE_OPTION == returnVal) {
file = chooser.getSelectedFile();
inString = file.getName();
inputText.setText(inString);
MainAlgorithm md5 = new MainAlgorithm(file);
outputString = md5.compute();
outputText.setText(outputString);
}
} else if (button == compare) { // MD5值比较
if (outputText.getText().equals("")) {
JOptionPane.showMessageDialog(null, "请先计算");
} else {
// if md5 values are the same
if (outputText.getText().equals(compareText.getText())) {
JOptionPane.showMessageDialog(null, "MD5值相同");
} else {// md5 values are different
JOptionPane.showMessageDialog(null, "MD5值不同");
}
}
} else if (button == empty) { // 重新初始化
inputText.setText(null);
outputText.setText(null);
compareText.setText(null);
file = null;
inString = null;
outputString = null;
compareString = null;
} else { // 反馈问题
try {
BareBonesBrowserLaunch.browse("http://blog.sina.com.cn/" +
"s/blog_03f9d36e0100qjqp.html");
} catch (IllegalArgumentException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (ClassNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IllegalAccessException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (InvocationTargetException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (NoSuchMethodException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
}
}
/*以下用浏览器打开指定网页的代码采用自互联网，网址没记下来，现在找不到，望原作见谅
*/
// open URL with a browser
class BareBonesBrowserLaunch {
public static void openURL(String url) {
try {
browse(url);
} catch (Exception e) {
JOptionPane.showMessageDialog(null,
"Error attempting to launch web browser:/n" +
e.getLocalizedMessage());
}
}
static void browse(String url) throws ClassNotFoundException,
IllegalAccessException, IllegalArgumentException,
InterruptedException, InvocationTargetException, IOException,
NoSuchMethodException {
String osName = System.getProperty("os.name", "");
if (osName.startsWith("Mac OS")) {
Class fileMgr = Class.forName("com.apple.eio.FileManager");
Method openURL = fileMgr.getDeclaredMethod("openURL",
new Class[] { String.class });
openURL.invoke(null, new Object[] { url });
} else if (osName.startsWith("Windows")) {
Runtime.getRuntime().exec(
"rundll32 url.dll,FileProtocolHandler " + url);
} else { // assume Unix or Linux
String[] browsers = { "firefox", "opera", "konqueror", "epiphany",
"mozilla", "netscape" };
String browser = null;
for (int count = 0; count < browsers.length && browser == null; count++)
if (Runtime.getRuntime()
.exec(new String[] { "which", browsers[count] })
.waitFor() == 0)
browser = browsers[count];
if (browser == null)
throw new NoSuchMethodException("Could not find web browser");
else
Runtime.getRuntime().exec(new String[] { browser, url });
}
}
}
计算文件MD5值的实现：
import java.io.*;
import java.security.*;
import javax.swing.JOptionPane;
public class MainAlgorithm {
MessageDigest md5;
File file;
MainAlgorithm( File inFile) {
try {
this.file = inFile;
md5 = MessageDigest.getInstance("MD5");
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
String compute () {
FileInputStream fis = null;
try {
fis = new FileInputStream(file);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
JOptionPane.showMessageDialog(null, "Couldn't find the file.");
e.printStackTrace();
}
byte[] input = new byte[1024];
int hasRead = 0;
try {
hasRead = fis.read(input);
while ( hasRead > 0) {
md5.update(input, 0, hasRead);
hasRead = fis.read(input);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
fis.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
byte[] result = md5.digest();
StringBuffer valueHex = new StringBuffer();
for ( int i = 0, tmp = 0; i < result.length; i++) {
tmp = result[i] & 0xff;
if ( tmp < 16) {
valueHex.append(0);
}
valueHex.append(Integer.toHexString(tmp));
}
return valueHex.toString();
}
}