java网络编程在发送文件再字符串遇到不能正常运行

Question

想着用java的网络编程，客户端先发送文件，服务端接收，客户端在发送一条语句，服务端已接受
但结果是文件没有完全接受（已保存，但是打不开），语句发出去却显示null
服务端代码

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
 
public class Test_Server {
    public static void main(String[] args) throws IOException {
        ServerSocket sockets=new ServerSocket(8899);
        Socket socket = sockets.accept();
        BufferedInputStream bufferedInputStream = new BufferedInputStream(socket.getInputStream());
        FileOutputStream fileOutputStream = new FileOutputStream("D:\\null2.jpg");
 
 
        int i=0;
        byte[] bytes=new byte[1024];
        while((i=bufferedInputStream.read(bytes))!=-1){
            fileOutputStream.write(bytes,0 ,i);
        }
        System.out.println("已接受文件");
 
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        String s = bufferedReader.readLine();
        System.out.println(s);
 
//        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(socket.getOutputStream());
//        bufferedOutputStream.write("copyRightNow".getBytes());
 
//        bufferedOutputStream.close();
        bufferedReader.close();
        fileOutputStream.close();
        bufferedInputStream.close();
 
    }
}
 

客户端代码

import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
 
public class Test_Client {
    public static void main(String[] args) throws IOException {
        Socket socket=new Socket(InetAddress.getLocalHost(),8899);
        OutputStream outputStream = socket.getOutputStream();
        BufferedOutputStream bufferedOutputStream=new BufferedOutputStream(outputStream);
//
//
        byte[] bytes=getBytes();
        bufferedOutputStream.write(bytes);
        System.out.println("已发送文件");
 
        //发送语句
        BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream));
        bufferedWriter.write("helloWorld");
        bufferedWriter.newLine();
        bufferedWriter.flush();
        socket.shutdownOutput();
        System.out.println("已发送语句");
 
        bufferedWriter.close();
        socket.close();
 
    }
    //获取二进制文件保存在bytes数组中
    public static byte[] getBytes() throws IOException {
        File file = new File("D:\\null.jpg");
        FileInputStream fileInputStream = new FileInputStream(file);
        int len=(int)file.length();
        byte[] bytes=new byte[len];
        int readLine;
        while((readLine= fileInputStream.read(bytes))!=-1){}
        fileInputStream.close();
        return bytes;
 
    }
}

Answer 1

• 这个问题的回答你可以参考下: https://ask.csdn.net/questions/7770797
• 这篇博客也不错, 你可以看下java小知识：把对象里的为null字符串转为空，给字段设置默认值
• 除此之外, 这篇博客: 120个java最常见的面试题，（上）中的 39. 如果对象的引用被置为 null，垃圾收集器是否会立即释放对象占用的内存？ 部分也许能够解决你的问题, 你可以仔细阅读以下内容或跳转源博客中阅读:
  

• 不会，在下一个垃圾回收周期中，这个对象将是可被回收的。