我查看了所有BuffedReader“未准备好”的问题,甚至与我正在寻找的内容略有关系,但我找不到解决问题的方法。
我有一个客户端和服务器使用适当的方法(即BufferedReader,PrintWriter)发送/接收字符串,但我的BufferedReader不起作用。当它遇到if循环,它检查BufferedReader是否准备就绪时,它将转到else语句并执行它的操作。老实说,我不知道如何解决这个问题。
总是感谢帮助,感谢您花时间阅读本文。
客户端代码:
import java.net.*;
import java.util.Scanner;
import java.io.*;
public class clientServer
{
public static void main (String [] args) throws IOException
{
//Opening Statement
System.out.println("Client/Server Program Utilizing Sockets!");
System.out.println();
//Opening/connected socket
String serverAddress = "127.0.0.1";
Socket socket = new Socket(serverAddress, 13000);
//Checks if connection is working
System.out.print("Connection: ");
if(socket.isConnected()== true)
{
System.out.println("Working...");
System.out.println();
}
else
{
System.err.println("Connection failed. Restart Program.");
System.exit(0);
}
//PrintWriter/BufferedReader instance/declaration to input/outputstream
PrintWriter out = new PrintWriter(socket.getOutputStream());
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
//User input statement
Scanner input = new Scanner (System.in);
System.out.print("Enter any greeting[s]: ");
String greetingInput = input.nextLine();
out.println(greetingInput); //Sends greetingInput to outputstream
out.flush(); //Did not turn on autoflush
System.out.println();
//Extra Statement
System.out.println("Sending Data...");
//Checking if PrintWriter has error
System.out.println("PrintWriter: " + out.checkError());
//Checks if BufferedReader is ready.
System.err.println("BufferedReader: " + in.ready());
System.out.println();
//If BufferedReader is ready, code will compute whatever mainServer sends
String serverResponse = null;
while((serverResponse = in.readLine()) != null )
{
if(in.ready() == true)
{
serverResponse += in.readLine();
System.out.println(serverResponse);
}
else
System.err.println("Buffer not ready!");
}
}
}
服务器端:
import java.net.*;
import java.io.*;
import java.util.*;
public class mainServer
{
public static void main (String [] args)throws IOException
{
ServerSocket echoServer = null;
try
{
echoServer = new ServerSocket (13000);
Socket socket = echoServer.accept();
try
{
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
String clientInput = in.readLine();
out.println("Client Input: " + clientInput);
out.println("Server Responese: Salutations, today's a wonderfully frosty day.");
out.flush();
}
catch(IOException e)
{
System.err.println("There was problem with BufferedReader/PrintWriter: " + e);
}
finally
{
socket.close();
}
}
catch(IOException e)
{
System.err.println("Error with Sockets: " + e);
}
finally
{
echoServer.close();
}
}
}
结果:
Client/Server Program Utilizing Sockets!
Connection: Working...
Enter any greeting[s]: Hi
Sending Data...
PrintWriter: false
BufferedReader: false
Buffer not ready!
Buffer not ready!
BUILD SUCCESSFUL (total time: 2 seconds)
答案 0 :(得分:3)
大部分代码没有意义。
Socket socket = new Socket(serverAddress, 13000);
//Checks if connection is working
System.out.print("Connection: ");
if(socket.isConnected()== true)
此测试无法失败。如果套接字没有连接,则会抛出异常,您将无法访问此部分代码。
//Checks if BufferedReader is ready.
为什么?
//If BufferedReader is ready, code will compute whatever mainServer sends
String serverResponse = null;
while((serverResponse = in.readLine()) != null )
{
if(in.ready() == true)
{
serverResponse += in.readLine();
System.out.println(serverResponse);
}
else
System.err.println("Buffer not ready!");
}
}
这都是胡说八道。进入循环后,已经在serverResponse
中有服务器响应的一行。然后,您正在检查更多输入,并将其下一行添加到serverResponse
,如果没有更多输入,则表示您正在处理整个好像根本没有任何数据的情况。鉴于您的服务器发送了两行响应,您需要在循环内执行的操作是打印serverResponse
并删除所有其余代码。 readLine()
将阻塞,直到数据到达,流结束或抛出异常。
您的客户端还需要在退出之前关闭套接字。
NB == true
和!= false
在遇到任何地方都是多余的。不要写这样的代码。
答案 1 :(得分:1)
@ EJP的回答是现货。我只想添加试图使用输入流和读者的ready()
方法的代码通常以这种或那种方式被破坏。
在这种情况下,ready()
调用没有实现任何有用的功能。最好只需调用readLine()
并让它阻塞,直到有一条线可用。