我有这个虚拟程序：
package com.company;
import javax.net.ssl.*;
import java.io.*;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketTimeoutException;
import java.security.*;
import java.security.cert.CertificateException;
class MyClass implements Serializable
{
private int i,j;
public MyClass(int i, int j)
{
this.i = i;
this.j = j;
}
public int getJ()
{
return j;
}
public void setJ(int j)
{
this.j = j;
}
public int getI()
{
return i;
}
public void setI(int i)
{
this.i = i;
}
}
class SSLContextHelper
{
static SSLContext createSSLContext(String path) throws KeyStoreException, UnrecoverableKeyException, NoSuchAlgorithmException, IOException, KeyManagementException, CertificateException
{
KeyStore keyStore = KeyStore.getInstance("PKCS12");
keyStore.load(new FileInputStream(path),"DSL2137976".toCharArray());
// Create key manager
KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("SunX509");
keyManagerFactory.init(keyStore, "DSL2137976".toCharArray());
KeyManager[] km = keyManagerFactory.getKeyManagers();
// Create trust manager
TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance("SunX509");
trustManagerFactory.init(keyStore);
TrustManager[] tm = trustManagerFactory.getTrustManagers();
// Initialize SSLContext
SSLContext sslContext = SSLContext.getInstance("TLSv1.2");
sslContext.init(km, tm, new SecureRandom());
return sslContext;
}
}
class ServerThread extends Thread
{
ServerSocket server;
Socket client;
ObjectOutputStream out;
ObjectInputStream in;
boolean issecure;
SSLContext sslContext;
public ServerThread(int port, boolean issecure) throws IOException, UnrecoverableKeyException, CertificateException, NoSuchAlgorithmException, KeyStoreException, KeyManagementException
{
this.issecure=issecure;
client=null;
if(issecure)
{
sslContext = SSLContextHelper.createSSLContext("/usr/lib/jvm/java-8-openjdk/jre/lib/security/ssltest");
SSLServerSocketFactory sslServerSocketFactory = sslContext.getServerSocketFactory();
server = sslServerSocketFactory.createServerSocket(port);
server.setSoTimeout(200);
}
else
server=new ServerSocket(port);
}
@Override
public void run()
{
while (true)
{
try
{
if(client==null)
{
if (issecure)
{
SSLSocket clientssl = (SSLSocket) server.accept();
clientssl.setEnabledCipherSuites(clientssl.getSupportedCipherSuites());
clientssl.startHandshake();
client = clientssl;
}
else
client = server.accept();
in = new ObjectInputStream(client.getInputStream());
out = new ObjectOutputStream(client.getOutputStream());
client.setSoTimeout(200);
}
String[] req = in.readUTF().split("\n");
out.writeUTF("hello I'm the server");
out.flush();
req = in.readUTF().split("\n");
out.writeUTF("I mean I'll serve you");
out.flush();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
}
public class Main
{
public static void main(String... args) throws IOException, ClassNotFoundException, UnrecoverableKeyException, CertificateException, NoSuchAlgorithmException, KeyStoreException, KeyManagementException
{
ServerThread serverThread=new ServerThread(14200, true);
serverThread.setDaemon(true);
serverThread.start();
ServerThread mail=new ServerThread(14201, false);
mail.setDaemon(true);
mail.start();
try
{
Thread.sleep(5000);
}
catch (InterruptedException e)
{
e.printStackTrace();
}
SSLSocket client=(SSLSocket)SSLContextHelper.createSSLContext("/usr/lib/jvm/java-8-openjdk/jre/lib/security/ssltest").getSocketFactory().createSocket();
client.connect(new InetSocketAddress("localhost",14200),5000);
Socket mailclient = new Socket();
mailclient.connect(new InetSocketAddress("localhost", 14201), 5000);
client.startHandshake();
client.setSoTimeout(5000);
ObjectOutputStream out = new ObjectOutputStream(client.getOutputStream());
ObjectInputStream in = new ObjectInputStream(client.getInputStream());
out.writeUTF("hello\nhow are you");
out.flush();
System.out.println(in.readUTF());
out.writeUTF("what\nI didn't understand");
out.flush();
System.out.println(in.readUTF());
int i=0;
while (i<=1)
{
try
{
try
{
Thread.sleep(10000);
}
catch (InterruptedException e)
{
e.printStackTrace();
}
out.writeUTF("hello\nhow are you");
out.flush();
System.out.println(in.readUTF());
out.writeUTF("what\nI didn't understand");
out.flush();
System.out.println(in.readUTF());
i++;
}
catch (SocketTimeoutException ignored)
{
}
}
}
}
它只是我所拥有的真实程序的模拟，客户端的Thread.sleep模拟用户在点击按钮之前与系统进行一些交互（第一次睡眠是模拟用户将登录信息，第二个睡眠是用户打开选项卡，点击链接，回答对话框等）。
不幸的是，在server.accept成功之后（即客户端连接时），我在服务器端获得了EOFException。
我知道当没有数据可以获得此异常时，即使在客户端这两行（while循环之前的第一行）之后也会发生这种情况：
out.writeUTF("hello\nhow are you");
out.flush();
在这两行之后，客户端等待5秒（我放置的超时），在此5秒内服务器保持其EOFException，当超时完成时，客户端获得SocketTimeoutException并退出程序。
原始程序在服务器端获得相同的EOFException，它在我移动到SSLSockets时开始。
那么这里的问题是什么？
我发现当我删除超时（读取超时而不是接受超时）时，它可以完美地工作。
使用超时，将其设置为不同的值会给我带来奇怪的NullPointerExceptions（in为空!!!!!!!!!!）。
我需要超时，因为在我的真实程序中，服务器不会永远等待客户端，它还有其他客户端也可以服务。
为什么超时导致这个？