Question

Java从命令行读取输入然后输出到文本文件的问题

import java.io.*;

public class InputName {
public static void main (String [] args)throws IOException{
System.out.println("请输入姓名（结束请敲两次回车键）：");//提示语
InputStreamReader keyBoard = new InputStreamReader(System.in);//读入用户输入，并将其转换为字符流
BufferedReader br = new BufferedReader(keyBoard);//建立输入缓冲区
File f = new File("name.txt");//创建name.txt文件
f.createNewFile();//若该文件原来不存在，则新建文件
FileWriter writer = new FileWriter(f,true);//新建输出器
String s;//用作输出的临时字符串

while((s=br.readLine())!=""){
writer.write(s);
}
writer.close();
keyBoard.close();
br.close();
}
}

请问为什么没法输出到name.txt？

Answer 1

import java.io.*;
public class InputName {
    public static void main(String[] args) throws IOException {
        System.out.println("请输入姓名（结束请敲两次回车键）：");
        InputStreamReader keyBoard = new InputStreamReader(System. in );
        BufferedReader br = new BufferedReader(keyBoard);
        FileWriter writer = new FileWriter("name.txt", true);
        String s;
        while ((s = br.readLine()) != null) {
            writer.write(s);
        }
        writer.flush();
        writer.close();
        keyBoard.close();
        br.close();
    }
}

追问

我试过了，还是没法输出到文件呀？

追答

import java.io.*;
public class InputName {
    public static void main(String[] args) throws IOException {
        System.out.println("请输入姓名 ：");
        InputStreamReader keyBoard = new InputStreamReader(System. in );
        BufferedReader br = new BufferedReader(keyBoard);
        FileWriter writer = new FileWriter("name.txt", true);
        String s;
        while (true) {
            s = br.readLine();
            if (!"".equals(s)) {
                writer.write(s);
                writer.flush();
            } else {
                writer.close();
                keyBoard.close();
                br.close();
                break;
            }
        }
    }
}