Java 如何将输出流设置为TextArea
我正在尝试为一个程序创建一个GUI面板,我想将所有通常打印到命令提示符的内容打印到TextArea对象。我的GUI面板大部分已格式化,但无法将文本打印到文本区域,以下是我的文件:Java 如何将输出流设置为TextArea,java,swing,user-interface,jframe,jtextarea,Java,Swing,User Interface,Jframe,Jtextarea,我正在尝试为一个程序创建一个GUI面板,我想将所有通常打印到命令提示符的内容打印到TextArea对象。我的GUI面板大部分已格式化,但无法将文本打印到文本区域,以下是我的文件: package guipanel; import javax.swing.*; import java.awt.*; import java.io.*; /** * * @author Dan */ public class GUIPanel extends JFrame { public GUI
package guipanel;
import javax.swing.*;
import java.awt.*;
import java.io.*;
/**
*
* @author Dan
*/
public class GUIPanel extends JFrame {
public GUIPanel() {
initComponents();
}
private void setOutputStream(boolean catchErrors) {
System.setOut(aPrintStream);
setVisible(true);
requestFocus();
if (catchErrors) {
System.setErr(aPrintStream);
}
}
private void addTabs(JTabbedPane jTabbedPane1) {
JPanel jPanel1 = new JPanel();
JPanel jPanel2 = new JPanel();
JPanel jPanel3 = new JPanel();
JPanel jPanel4 = new JPanel();
jTabbedPane1.add("Main", textArea1);
jTabbedPane1.add("Commands", jPanel);
jTabbedPane1.add("Rules", jPanel1);
jTabbedPane1.add("Links", jPanel2);
jTabbedPane1.add("Information", jPanel3);
jTabbedPane1.add("Shutdown", jPanel4);
setOutputStream(true);
}
@SuppressWarnings("unchecked")
private void initComponents() {
textArea1 = new java.awt.TextArea();
jTabbedPane1 = new javax.swing.JTabbedPane();
jMenuBar1 = new javax.swing.JMenuBar();
jMenu1 = new javax.swing.JMenu();
jMenu2 = new javax.swing.JMenu();
textArea1.setPreferredSize(new java.awt.Dimension(432, 343));
textArea1.getAccessibleContext().setAccessibleParent(jTabbedPane1);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Evolution-X 639");
setBounds(new java.awt.Rectangle(0, 0, 400, 450));
setResizable(false);
getContentPane().setLayout(new java.awt.FlowLayout());
addTabs(jTabbedPane1);
getContentPane().add(jTabbedPane1);
jMenu1.setText("File");
jMenuBar1.add(jMenu1);
jMenu2.setText("Edit");
jMenuBar1.add(jMenu2);
setJMenuBar(jMenuBar1);
pack();
}
public static void main(String args[]) {
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(GUIPanel.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(GUIPanel.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(GUIPanel.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(GUIPanel.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new GUIPanel().setVisible(true);
}
});
}
private JMenu jMenu1;
private JMenu jMenu2;
private JMenuBar jMenuBar1;
private JTabbedPane jTabbedPane1;
private TextArea textArea1;
private JPanel jPanel = new JPanel();
private PrintStream aPrintStream =
new PrintStream(
new FilterOutputStream(
new ByteArrayOutputStream()));
}
您需要将打印流重定向到可以控制的输出流 这是我为一个我正在为工作而开发的应用程序开发的概念示例。当输出控制台在用户站点上运行时,我们使用它来打开输出控制台,这样我们就可以查看发送到standard out的内容……直到我们修复了日志记录(即;) 基本上,它在打印流和控制台之间放置一个定制的
OutputStream
,以捕获输出,但仍然允许将内容打印到控制台。如果您是从命令行或IDE运行程序,这将非常有用。如果你想的话,你可以用开关来阻止这一切
public class TestRedirect {
public static void main(String[] args) {
new TestRedirect();
}
public TestRedirect() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
CapturePane capturePane = new CapturePane();
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(capturePane);
frame.setSize(200, 200);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
PrintStream ps = System.out;
System.setOut(new PrintStream(new StreamCapturer("STDOUT", capturePane, ps)));
System.out.println("Hello, this is a test");
System.out.println("Wave if you can see me");
}
});
}
public class CapturePane extends JPanel implements Consumer {
private JTextArea output;
public CapturePane() {
setLayout(new BorderLayout());
output = new JTextArea();
add(new JScrollPane(output));
}
@Override
public void appendText(final String text) {
if (EventQueue.isDispatchThread()) {
output.append(text);
output.setCaretPosition(output.getText().length());
} else {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
appendText(text);
}
});
}
}
}
public interface Consumer {
public void appendText(String text);
}
public class StreamCapturer extends OutputStream {
private StringBuilder buffer;
private String prefix;
private Consumer consumer;
private PrintStream old;
public StreamCapturer(String prefix, Consumer consumer, PrintStream old) {
this.prefix = prefix;
buffer = new StringBuilder(128);
buffer.append("[").append(prefix).append("] ");
this.old = old;
this.consumer = consumer;
}
@Override
public void write(int b) throws IOException {
char c = (char) b;
String value = Character.toString(c);
buffer.append(value);
if (value.equals("\n")) {
consumer.appendText(buffer.toString());
buffer.delete(0, buffer.length());
buffer.append("[").append(prefix).append("] ");
}
old.print(c);
}
}
}
更新了工作示例。在Windows 7、Java 6和Mac OS Lion Java 7上测试我喜欢MadProgrammer的答案,但我认为这对UTF-8字符不起作用 相反,我会让StreamCapturer通过TearrayOutputStream进行扩展,并将其用作写实现
@Override
public void write(int b){
if ('\n' == (char) b) {
consumer.appendText(toString());
reset();
}
else {
super.write(b);
}
old.write(b);
}
我跳过前缀部分,因为我的实现中不需要它。不过谢谢你的代码,它帮了大忙 MadProgrammer的解决方案真的很棒,我的基于他的。 然而,正如Loopkin所指出的,它不处理特殊字符(准确地说,它在每个非ASCII字符上都失败) Loopkin的解决方案对我不起作用,但我最终想出了两个解决方案 解决方案1:处理每个1字节字符(最多U+00FF) 这个简单的解决方案处理U+00FF(每个1字节字符)以下的每个字符。 除了
write()
定义为:
@Override
public void write(int b) throws IOException {
buffer.append(Character.toChars((b + 256) % 256));
if ((char) b == '\n') {
textArea.append(str);
textArea.setCaretPosition(textArea.getDocument().getLength());
buffer.delete(0, buffer.length());
}
old.write(b);
}
我没有把前缀的东西,因为我不需要它
解决方案2:像处理标准输出一样处理每个对象
最后,我决定包含所有字符,因此我直接扩展了PrintStream
,并将前缀/缩进放回原处。问题是我无法重写私有方法write(String s)
,因此我重写了所有print()
方法:
public class PrintStreamCapturer extends PrintStream {
private JTextArea text;
private boolean atLineStart;
private String indent;
public PrintStreamCapturer(JTextArea textArea, PrintStream capturedStream, String indent) {
super(capturedStream);
this.text = textArea;
this.indent = indent;
this.atLineStart = true;
}
public PrintStreamCapturer(JTextArea textArea, PrintStream capturedStream) {
this(textArea, capturedStream, "");
}
private void writeToTextArea(String str) {
if (text != null) {
synchronized (text) {
text.setCaretPosition(text.getDocument().getLength());
text.append(str);
}
}
}
private void write(String str) {
String[] s = str.split("\n", -1);
if (s.length == 0)
return;
for (int i = 0; i < s.length - 1; i++) {
writeWithPotentialIndent(s[i]);
writeWithPotentialIndent("\n");
atLineStart = true;
}
String last = s[s.length - 1];
if (!last.equals("")) {
writeWithPotentialIndent(last);
}
}
private void writeWithPotentialIndent(String s) {
if (atLineStart) {
writeToTextArea(indent + s);
atLineStart = false;
} else {
writeToTextArea(s);
}
}
private void newLine() {
write("\n");
}
@Override
public void print(boolean b) {
synchronized (this) {
super.print(b);
write(String.valueOf(b));
}
}
@Override
public void print(char c) {
synchronized (this) {
super.print(c);
write(String.valueOf(c));
}
}
@Override
public void print(char[] s) {
synchronized (this) {
super.print(s);
write(String.valueOf(s));
}
}
@Override
public void print(double d) {
synchronized (this) {
super.print(d);
write(String.valueOf(d));
}
}
@Override
public void print(float f) {
synchronized (this) {
super.print(f);
write(String.valueOf(f));
}
}
@Override
public void print(int i) {
synchronized (this) {
super.print(i);
write(String.valueOf(i));
}
}
@Override
public void print(long l) {
synchronized (this) {
super.print(l);
write(String.valueOf(l));
}
}
@Override
public void print(Object o) {
synchronized (this) {
super.print(o);
write(String.valueOf(o));
}
}
@Override
public void print(String s) {
synchronized (this) {
super.print(s);
if (s == null) {
write("null");
} else {
write(s);
}
}
}
@Override
public void println() {
synchronized (this) {
newLine();
super.println();
}
}
@Override
public void println(boolean x) {
synchronized (this) {
print(x);
newLine();
super.println();
}
}
@Override
public void println(char x) {
synchronized (this) {
print(x);
newLine();
super.println();
}
}
@Override
public void println(int x) {
synchronized (this) {
print(x);
newLine();
super.println();
}
}
@Override
public void println(long x) {
synchronized (this) {
print(x);
newLine();
super.println();
}
}
@Override
public void println(float x) {
synchronized (this) {
print(x);
newLine();
super.println();
}
}
@Override
public void println(double x) {
synchronized (this) {
print(x);
newLine();
super.println();
}
}
@Override
public void println(char x[]) {
synchronized (this) {
print(x);
newLine();
super.println();
}
}
@Override
public void println(String x) {
synchronized (this) {
print(x);
newLine();
super.println();
}
}
@Override
public void println(Object x) {
String s = String.valueOf(x);
synchronized (this) {
print(s);
newLine();
super.println();
}
}
}
只需更新NOOBS的原始程序员代码-将JTextArea参数传递给构造函数,例如
new RedirectText(Main.window.textArea1);
aPrintStream在哪里?我也不会对错误流和输出流使用相同的打印流,您可能需要区分私有打印流aPrintStream=new PrintStream(new FilterOutputStream(new ByteArrayOutputStream());感谢大家的提醒,我已经纠正了这个错误,并在Windows(Java 6和7)和Mac OS Lion(Java 7)上进行了测试。很抱歉出现了这个错误,尝试变得聪明:在运行时显示控制台输出怎么样?你能举个例子吗?@BilalHasan这将输出程序输出到标准输出的任何东西。你想做什么?嗨,我已经告诉你如何显示System.out.println(“控制台打印”);在文本区域,但我面临一个问题。我有一个功能,这是我的应用程序中的主要工作。它从一些网站上截取数据并解析它们,在这个方法中,我有几个控制台输出。现在的问题是,如果我尝试打印控制台输出(仅用于测试),而不调用此方法,则textarea会显示每个测试打印。但是如果我调用这个方法并测试打印,我会看到空白文本区域。需要帮助。您只需更改
JTextArea
new RedirectText(Main.window.textArea1);