system.out输出到文件上

public class SayInFile {
    public SayInFile(){
        try {
            //文件生成路径
            PrintStream ps=new PrintStream("D:\\role.txt");
            System.setOut(ps);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) {
        System.out.println("我在文件里了！");
    }
}