標籤：cmd
郭嘉
郵箱：[email protected]
部落格：http://blog.csdn.net/allenwells
github：https://github.com/AllenWell
原理：
Process process = Runtime.getRuntime().exec("cmd order");注意：
如果exec()中只有CMD命令，則命令會直接被執行，而不會開啟命令列視窗；
舉例：
下面例子實現了執行解壓JAR包，並把命令列資訊輸到Java的圖形介面的功能：
Process process = null;try{ process = Runtime.getRuntime().exec("jar xvf " + jarInputFile.getPath()) ;}catch (IOException e){ e.printStackTrace();}InputStream inputStream = process.getInputStream();Reader reader = new InputStreamReader(inputStream);BufferedReader bufferedReader = new BufferedReader(reader);try{ for(String s = ""; ( s = bufferedReader.readLine()) != null;) { consoleInfo.append(s + "<br>"); } bufferedReader.close(); reader.close(); JLabel consoleLabel = new JLabel(); consoleLabel.setText("<html>" + consoleInfo.toString() + "</html>"); }}catch (/ e){ e.printStackTrace();}注意：Java Swing的文字顯示不支援直接“\n”換行，所以使用“”標籤的形式來實現換行。
二 CMD輸出資訊重新導向以上程式展示的是把執行一條命令後，把命令列上的資訊輸出到Java的圖形介面上，那麼如何?即時的檢測Windows的命令列列印資訊並進行輸出呢？
實現方法：
Java的System類中有個out成員變數，稱為標準輸出資料流，用來把列印輸出到螢幕上。上面所述的問題其實就是System.out的輸出重新導向問題。
System.out在Java中源碼實現如下所示：
/** * Default input stream. */ public static final InputStream in; /** * Default output stream. */ public static final PrintStream out; /** * Default error output stream. */ public static final PrintStream err; private static final String lineSeparator; private static Properties systemProperties; static { err = new PrintStream(new FileOutputStream(FileDescriptor.err)); out = new PrintStream(new FileOutputStream(FileDescriptor.out)); in = new BufferedInputStream(new FileInputStream(FileDescriptor.in)); lineSeparator = System.getProperty("line.separator"); }從上面可以看出，System.out是一個PrintStream。只需要把它重新導向到我們需要的地方就可以了，具體代碼實現如下所示：
package com.allenwells.ui;import java.awt.Color;import java.awt.Dimension;import java.io.OutputStream;import java.io.PrintStream;import javax.swing.JScrollPane;import javax.swing.JTextPane;import javax.swing.SwingUtilities;import javax.swing.text.AbstractDocument;import javax.swing.text.BadLocationException;import javax.swing.text.Document;import javax.swing.text.Element;import javax.swing.text.Style;import javax.swing.text.StyleConstants;import javax.swing.text.StyledDocument;public class ConsolePane extends JScrollPane{ private static final long serialVersionUID = 1L; private JTextPane textPane = new JTextPane(); private static ConsolePane console = null; public static synchronized ConsolePane getInstance() { if (console == null) { console = new ConsolePane(); } return console; } private ConsolePane() { setViewportView(textPane); // Set up System.out PrintStream mySystemOut = new MyPrintStream(System.out, Color.black); System.setOut(mySystemOut); // Set up System.err PrintStream mySystemErr = new MyPrintStream(System.err, Color.red); System.setErr(mySystemErr); textPane.setEditable(true); setPreferredSize(new Dimension(640, 120)); } /** * Returns the number of lines in the document. */ private final int getLineCount() { return textPane.getDocument().getDefaultRootElement().getElementCount(); } /** * Returns the start offset of the specified line. * * @param line * The line * @return The start offset of the specified line, or -1 if the line is * invalid */ private int getLineStartOffset(int line) { Element lineElement = textPane.getDocument().getDefaultRootElement() .getElement(line); if (lineElement == null) return -1; else return lineElement.getStartOffset(); } /** * 清除超過行數時前面多出行的字元 */ private void replaceRange(String str, int start, int end) { if (end < start) { throw new IllegalArgumentException("end before start"); } Document doc = textPane.getDocument(); if (doc != null) { try { if (doc instanceof AbstractDocument) { ((AbstractDocument) doc).replace(start, end - start, str, null); } else { doc.remove(start, end - start); doc.insertString(start, str, null); } } catch (BadLocationException e) { throw new IllegalArgumentException(e.getMessage()); } } } class MyPrintStream extends PrintStream { private Color foreground; // 輸出時所用字型顏色 /** * 構造自己的 PrintStream * * @param out * 可傳入 System.out 或 System.err, 實際不起作用 * @param foreground * 顯示字型顏色 */ MyPrintStream(OutputStream out, Color foreground) { super(out, true); // 使用自動重新整理 this.foreground = foreground; } /** * 在這裡重截,所有的列印方法都要調用最底一層的方法 */ public void write(byte[] buf, int off, int len) { final String message = new String(buf, off, len); /** SWING非介面線程訪問組件的方式 */ SwingUtilities.invokeLater(new Runnable() { public void run() { try { StyledDocument doc = (StyledDocument) textPane .getDocument(); // Create a style object and then set the style // attributes Style style = doc.addStyle("StyleName", null); // Foreground color StyleConstants.setForeground(style, foreground); doc.insertString(doc.getLength(), message, style); } catch (BadLocationException e) { // e.printStackTrace(); } // Make sure the last line is always visible textPane.setCaretPosition(textPane.getDocument() .getLength()); // Keep the text area down to a certain line count int idealLine = 150; int maxExcess = 50; int excess = getLineCount() - idealLine; if (excess >= maxExcess) { replaceRange("", 0, getLineStartOffset(excess)); } } }); } }}使用方法
JPanel contentPanel = new JPanel();ConsolePane consolePane = ConsolePane.getInstance();contentPanel.add(consolePane);如下所示：
附錄：這裡給出常見的CMD命令：
著作權聲明：本文為博主原創文章，未經博主允許不得轉載。
【Java基礎】Java與Windows系統的互動
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