Question

我已经按照一些教程创建了一个可以同时处理多个客户端的基本服务器。它正确地接收数据，但它会占用越来越多的内存，直到它耗尽堆空间。我相信这是因为我的循环不能识别我的结束角色而离开for循环。

以下是接收数据的线程的代码：

 while (true){

            try {
                is = new BufferedInputStream(s.getInputStream());
                InputStreamReader isr = new InputStreamReader(is);
                int character;
                StringBuilder process = new StringBuilder();

                try {
                    while((character = isr.read()) != 13) {
                        process.append((char)character); //here is the issue - it just continues to append until it runs out of memory
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                parent.parent.writeToLog("Client " + Integer.toString(num) + " sent a message: " + process.toString());
                System.out.println(process);

                is = null;

            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }

            BufferedOutputStream os;
            try {
                os = new BufferedOutputStream(s.getOutputStream());
                OutputStreamWriter osw = new OutputStreamWriter(os);
                osw.write("Response from server at client socket " + Integer.toString(num) + " at " + (new java.util.Date()).toString());
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

我在代码中添加了注释，它向我显示了堆栈跟踪上的错误。这是客户端，它只是Java教程中的EchoClient：

  import java.io.*;
import java.net.*;
import java.util.Random;

public class EchoClient {
    public static void main(String[] args) throws IOException {

        Socket echoSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;

        try {
            echoSocket = new Socket("localhost", 2405);
            out = new PrintWriter(echoSocket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(echoSocket.getInputStream()));
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: taranis.");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for "
                    + "the connection to: taranis.");
            System.exit(1);
        }

        BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));

        out.println("Message to host: hello" + (char) 13);

        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        out.println(Integer.toString((new Random()).nextInt()) + (char) 13);

        out.close();
        in.close();
        stdIn.close();
        echoSocket.close();
    }
}

你可以看到我将字符13附加到输出的位置，这就是结束循环的意思但是根据我的理解，这不起作用。任何人都可以帮我解决这个问题吗？

Answer 1

我认为问题在于以下代码：

                while((character = isr.read()) != 13) {
                    process.append((char)character); //here is the issue - it just continues to append until it runs out of memory
                }

即使到达流的末尾，isr.read()也会返回-1而不是13.您可能永远不会收到13退出循环的输入字符。

Answer 2

这可能是问题所在：while((character = isr.read()) != 13)

你为什么要检查13？如果到达流的末尾，InputStreamReader.read()将返回-1。

我的猜测是你正在点击流的末尾并用垃圾填充你的StringBuilder。请注意，(char)-1实际上代表unicode字符65535。

从套接字读取数据并将其附加到stringbuilder的问题

2 个答案: