使用Java的输入输出流将一个文本文件的内容按行读出，每读出一行，就顺序添加行号，并写入到另一个文件中。
```java
import java.io.*;
public class E {
public static void main(String args[]) {
File file = new File("E.java");
File tempFile = new File("temp.txt");
try {
FileReader inOne = new FileReader(file);
BufferedReader inTwo = new BufferedReader(inOne);
FileWriter tofile = new FileWriter(tempFile);
BufferedWriter out = new BufferedWriter(tofile);
String s = null;
int i = 0;
s = inTwo.readLine();
while (s != null) {
i++;
out.write(i + " " + s);