控制输入流，从控制台打印到文件中，更改输出的位置

 public static void main(String[] args) throws IOException {
        PrintStream printStream = System.out;
        //在默认情况下，PrintStream 输出数据的位置 标准输出，即显示器
        printStream.print("Tom,hello");
        /*
          public void print(String s) {
              if (s == null) {
                 s = "null";
              }
               write(s);
             }
         */
        //因为print底层使用的是write，所以我们可以直接调用write进行打印/输出
 
        printStream.write("你好，元宇宙".getBytes());//write是字节流
        //我们可以修改打印流的位置/设备
        //1.输出修改成到"e:\\f1.txt"
        //2."Tom,hello" 就会输出到 "e:\\f1.txt"
        System.setOut(new PrintStream("E:\\f1.txt"));
        printStream.print("Tom,hello");
        System.out.println("打印完毕~");//已经打印到文件中
        printStream.close();
    }

便捷方式：

 public static void main(String[] args) throws IOException {
        PrintStream printStream = new PrintStream("E:\\f1.txt");
        printStream.println("Tom,hello");
        printStream.write("你好，元宇宙".getBytes());
        System.out.println("已经打印到文件中~");
        printStream.close();
    }

 

 public static void main(String[] args) throws IOException {
//        PrintWriter printWriter = new PrintWriter(System.out);
        PrintWriter printWriter = new PrintWriter(new FileWriter("E:\\f2.txt"));
        printWriter.print("hi,铜陵你好~");
        System.out.println("打印完成!");
        printWriter.close();
    }

 更改输出的位置~