Java-重定义标准输出和错误

刚接触到错误日志的时候觉得很神奇，今天学习了一番后用代码写了出来。

 package com.tj;

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.PrintStream;

 public class TeeStream extends PrintStream {
     PrintStream out;

     public TeeStream(PrintStream out1, PrintStream out2) {
         super(out1);
         this.out = out2;
     }

     public void write(byte buf[], int off, int len) {
         try {
             super.write(buf, off, len);
             out.write(buf, off, len);
         } catch (Exception e) {
         }
     }

     public void flush() {
         super.flush();
         out.flush();
     }

     public static void main(String[] args) {
         try {
             //Tee 标准输出
             PrintStream out = new PrintStream(new FileOutputStream("E:" + File.separator + "out.log"));
             PrintStream tee = new TeeStream(System.out, out);

             System.setOut(out);

             //Tee 标准错误
             PrintStream err = new PrintStream(new FileOutputStream("E:" + File.separator + "err.log"));
             tee = new TeeStream(System.err, err);

             System.setErr(tee);
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         }

         System.out.println("welcome");
         System.err.println("error");
     }
 }