System.out输出到文件
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintStream;

public class 打印输出到文件 {
public static void main(String[] args){
try {
FileOutputStream fos = new FileOutputStream("d://xxx.txt");

PrintStream ps = new PrintStream(fos);
System.setOut(ps);
int c = 0;
while (c <= 100) {
System.out.println(c++);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}