byte[] buf = new byte[1024];
        int len = is.read(buf);
        String getStr = new String(buf, 0, len);//String getStr = new String(buf, 0, is.read(buf));
        System.out.println(getStr);

        ss.close();
        s.close();
我在复习TCP传输客户端的时候发现，如果红色的代码，用注释后的代码就会报错！read（）是读buf并且将所读的保存在缓冲数字buf中，那么在写read（buf），编译不会报错？但是运行时是会报错的，因为buf不在是byte数组，但是byte数组跟缓冲行数组又有什么区别？为什么会报错？

贴完整的代码出来看看

public class ServerDemo {

    public static void main(String[] args) throws IOException {
        
        
        ServerSocket ss = new ServerSocket(8888);
        Socket s = ss.accept();
        String ip = s.getInetAddress().getHostAddress();
        
        InputStream is = s.getInputStream();
        
        byte[] buf = new byte[1024];
        int len = is.read(buf);
        String message = new String(buf,0,len);
        System.out.println("客户端为："+ip+" 的 发来信息：  "+message);
    }

}

试试强制类型转换
String getStr = new String(buf, 0, (int)(is.read(buf)));

没报错啊
import
import
import
import
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(8888);
        Socket s = ss.accept();
        String ip = s.getInetAddress().getHostAddress();
        InputStream is = s.getInputStream();
        byte[] buf = new byte[1024];
        /*int len = is.read(buf);
        String message = new String(buf,0,len);*/
        String message = new String(buf,0,is.read(buf));
        System.out.println("客户端为："+ip+" 的 发来信息：  "+message);
    }
}

import
import
import
import


public class ClientDemo {
    public static void main(String[] args) throws UnknownHostException, IOException{        
        Socket client=new Socket("192.168.1.101",8888);        
        OutputStream out=client.getOutputStream();        
        byte[] b="hello".getBytes();
        out.write(b, 0, b.length);
        out.close();
        client.close();
    }
}

我转了，也错

我讲的不够好，你可能没理解我的意思

这是服务端：
ublic class ServerDemo {

    public static void main(String[] args) throws IOException {
        
        
        ServerSocket ss = new ServerSocket(8887);
        Socket s = ss.accept();
        String ip = s.getInetAddress().getHostAddress();
        
        InputStream is = s.getInputStream();
        
        byte[] buf = new byte[1024];
        //is.read(buf)
        String message = new String(buf,0,is.read(buf));
        System.out.println("客户端为："+ip+" 的 发来信息：  "+message);
    }

}
客户端：
public class ClientDemo {


    public static void main(String[] args) throws UnknownHostException, IOException {
        
        Socket s = new Socket("127.0.0.1",8887);
        OutputStream os = s.getOutputStream();
        os.write(" 你妹啊  ".getBytes() );
        
        
        

    }

}
注释部分的代码如果写上去，运行客户端就会报错！不写就不会报错，好难理解原有！

好了，转换就没有报错了，看来是这样的！刚才弄错了！还以为报错了！

String message = new String(buf,0,is.read(buf));
string构造中的第三个参数应该是用来给长度的，可是为什么要用is.read(buf)呢？
可不可以个解释一下