这是我连接两个Socket而没有任何ServerSocket的代码：
package primary;
import java.awt.FlowLayout;
import java.io.EOFException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.concurrent.*;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class Client extends JFrame implements Runnable {
private final String myName;
private ServerSocket listener;
private Socket connection1;
private Socket connection2;
private ObjectOutputStream output1;
private ObjectOutputStream output2;
private ObjectInputStream input1;
private ObjectInputStream input2;
private Object receiveObject;
private Object1 sendObject1;
private Object2 sendObject2;
private final int[] myLocalPort;
private final int[] connectionPort;
private ExecutorService service;
private Future<Boolean> future1;
private Future<Boolean> future2;
public Client(final String myName, int[] myLocalPort, int[] connectionPort) {
super(myName);
this.myName = myName;
this.myLocalPort = myLocalPort;
this.connectionPort = connectionPort;
sendObject1 = new Object1("string1", "string2", myName);
sendObject2 = new Object2("string1", 2.5, 2, true, myName);
initComponents();
}
public void exe() {
ExecutorService eService = Executors.newCachedThreadPool();
eService.execute(this);
}
@Override
public void run() {
try {
displayMessage("Attempting connection\n");
try {
connection1 = new Socket(InetAddress.getByName("localhost"), connectionPort[0],
InetAddress.getByName("localhost"), myLocalPort[0]);
displayMessage(myName + " connection1\n");
} catch (Exception e) {
displayMessage("failed1\n");
System.err.println("1" + myName + e.getMessage() + "\n");
}
try {
connection2 = new Socket(InetAddress.getByName("localhost"), connectionPort[1],
InetAddress.getByName("localhost"), myLocalPort[1]);
displayMessage(myName + " connection2\n");
} catch (Exception e) {
displayMessage("failed2\n");
System.err.println("2" + myName + e.getMessage() + "\n");
}
displayMessage("Connected to: " + connection1.getInetAddress().getHostName() + "\n\tport: "
+ connection1.getPort() + "\n\tlocal port: " + connection1.getLocalPort() + "\n"
+ connection2.getInetAddress().getHostName() + "\n\tport: " + connection2.getPort()
+ "\n\tlocal port: " + connection2.getLocalPort() + "\n\n");
output1 = new ObjectOutputStream(connection1.getOutputStream());
output1.flush();
output2 = new ObjectOutputStream(connection2.getOutputStream());
output2.flush();
input1 = new ObjectInputStream(connection1.getInputStream());
input2 = new ObjectInputStream(connection2.getInputStream());
displayMessage("Got I/O stream\n");
setTextFieldEditable(true);
service = Executors.newFixedThreadPool(2);
future1 = service.submit(
new Callable<Boolean>() {
@Override
public Boolean call() throws Exception {
try {
processConnection(input1);
displayMessage("input1 finished");
} catch (IOException e) {
displayMessage("blah");
}
return true;
}
});
future2 = service.submit(
new Callable<Boolean>() {
@Override
public Boolean call() throws Exception {
try {
processConnection(input2);
displayMessage("input2 finished");
} catch (IOException e) {
displayMessage("foo");
}
return true;
}
});
} catch (UnknownHostException e) {
displayMessage("UnknownHostException\n");
e.printStackTrace();
} catch (EOFException e) {
displayMessage("EOFException\n");
e.printStackTrace();
} catch (IOException e) {
displayMessage("IOException\n");
e.printStackTrace();
} catch(NullPointerException e) {
System.err.println("asdf " + e.getMessage());
} finally {
try {
displayMessage("i'm here\n");
if((future1 != null && future1.get()) && (future2 != null && future2.get())) {
displayMessage(future1.get() + " " + future2.get() + "\n");
displayMessage("Closing Connection\n");
setTextFieldEditable(false);
if(!connection1.isClosed()) {
output1.close();
input1.close();
connection1.close();
}
if(!connection2.isClosed()) {
output2.close();
input2.close();
connection2.close();
}
displayMessage("connection closed\n");
}
} catch (IOException e) {
displayMessage("IOException on closing");
} catch (InterruptedException e) {
displayMessage("InterruptedException on closing");
} catch (ExecutionException e) {
displayMessage("ExecutionException on closing");
}
}
}//method run ends
private void processConnection(ObjectInputStream input) throws IOException {
String message = "";
do {
try {
receiveObject = input.readObject();
if(receiveObject instanceof String) {
message = (String) receiveObject;
displayMessage(message + "\n");
} else if (receiveObject instanceof Object1) {
Object1 receiveObject1 = (Object1) receiveObject;
displayMessage(receiveObject1.getString1() + " " + receiveObject1.getString2()
+ " " + receiveObject1.toString() + "\n");
} else if (receiveObject instanceof Object2) {
Object2 receiveObject2 = (Object2) receiveObject;
displayMessage(receiveObject2.getString1() + " " + receiveObject2.getD()
+ " " + receiveObject2.getI() + " " + receiveObject2.toString() + "\n");
}
} catch (ClassNotFoundException e) {
displayMessage("Unknown object type received.\n");
}
displayMessage(Boolean.toString(message.equals("terminate\n")));
} while(!message.equals("terminate"));
displayMessage("finished\n");
input = null;
}
private void initComponents() {
dataField = new javax.swing.JTextField();
sendButton1 = new javax.swing.JButton();
sendButton2 = new javax.swing.JButton();
jScrollPane1 = new javax.swing.JScrollPane();
resultArea = new javax.swing.JTextArea();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setLayout(new FlowLayout());
dataField.setEditable(false);
dataField.setColumns(20);
dataField.addActionListener(new java.awt.event.ActionListener() {
@Override
public void actionPerformed(java.awt.event.ActionEvent evt) {
dataFieldActionPerformed(evt);
}
});
sendButton1.setText("Send Object 1");
sendButton1.addActionListener(new java.awt.event.ActionListener() {
@Override
public void actionPerformed(java.awt.event.ActionEvent evt) {
sendButton1ActionPerformed(evt);
}
});
sendButton2.setText("Send Object 2");
sendButton2.addActionListener(new java.awt.event.ActionListener() {
@Override
public void actionPerformed(java.awt.event.ActionEvent evt) {
sendButton2ActionPerformed(evt);
}
});
resultArea.setColumns(25);
resultArea.setRows(15);
resultArea.setEditable(false);
resultArea.setRows(5);
jScrollPane1.setViewportView(resultArea);
add(dataField);
add(sendButton1);
add(sendButton2);
add(jScrollPane1);
pack();
}
private void dataFieldActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
sendData(evt.getActionCommand());
dataField.setText("");
}
private void sendButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
sendData(sendObject1);
}
private void sendButton2ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
sendData(sendObject2);
}
private void displayMessage(final String messageToDisplay) {
SwingUtilities.invokeLater(
new Runnable() {
@Override
public void run() {
resultArea.append(messageToDisplay);
}
});
}
private void setTextFieldEditable(final boolean editable) {
SwingUtilities.invokeLater(
new Runnable() {
@Override
public void run() {
dataField.setEditable(editable);
}
});
}
private void sendData(final Object object) {
try {
output1.writeObject(object);
output1.flush();
output2.writeObject(object);
output2.flush();
displayMessage(myName + ": " + object.toString() + "\n");
} catch (IOException e) {
displayMessage("Error writing object\n");
}
}
private javax.swing.JTextField dataField;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextArea resultArea;
private javax.swing.JButton sendButton1;
private javax.swing.JButton sendButton2;
}
主要：
package primary;
import javax.swing.SwingUtilities;
public class Main {
private static Object locker;
public static void main(String[] args) {
locker = new Object();
final int[][] a = new int[6][];
final int[][] b = new int[6][];
final int[][] c;
a[0] = new int[] {12340, 12341};
a[1] = new int[] {12342, 12344};
a[2] = new int[] {12342, 12343};
a[3] = new int[] {12340, 12345};
a[4] = new int[] {12344, 12345};
a[5] = new int[] {12341, 12343};
b[0] = new int[] {22340, 22341};
b[1] = new int[] {22342, 22344};
b[2] = new int[] {22342, 22343};
b[3] = new int[] {22340, 22345};
b[4] = new int[] {22344, 22345};
b[5] = new int[] {22341, 22343};
c = a;
SwingUtilities.invokeLater(
new Runnable() {
@Override
public void run() {
Client client1 = new Client("client1", c[0], c[1]);
client1.exe();
client1.setLocation(0, 0);
client1.setVisible(true);
}
});
SwingUtilities.invokeLater(
new Runnable() {
@Override
public void run() {
Client client2 = new Client("client2", c[2], c[3]);
client2.exe();
client2.setLocation(0, 200);
client2.setVisible(true);
}
});
SwingUtilities.invokeLater(
new Runnable() {
@Override
public void run() {
Client client3 = new Client("client3", c[4], c[5]);
client3.exe();
client3.setLocation(0, 400);
client3.setVisible(true);
}
});
}
}
此处Object1和Object2只是两个可序列化对象。似乎所有插座都完美连接。如果我退出系统而不调用套接字及其输入的close（）方法，输出流并重新运行，它仍然可以正常工作。但是如果我确保调用close（）方法后退出系统，并且我再次重新运行，我得到这个：
1client2Address已在使用中：connect
1client3Address already in use: connect
2client3Address already in use: connect
asdf null
1client1Connection refused: connect
2client2Connection refused: connect
asdf null
2client1Connection refused: connect
asdf null
我一次又一次地重复奔跑，我不断得到这个，除非，我等了一段时间再重新跑步，它第一次运作得很好。
为什么会发生这样的事情？为什么如果我关闭套接字而不关闭套接字需要花费这么多时间？当我不关闭套接字时，它们是真的关闭还是仅仅连接现有连接？但是当使用ServerSocket时，在我关闭时似乎不会发生这种情况。究竟发生了什么？
另一个问题，ServerSocket据说将Socket的连接发送到一个本地端口，而不是它正在侦听的端口。如果是真的，为什么我在调用Socket.getLocalPort（）时，为它接受的所有套接字获取监听localport？
答案 0 :(得分：1)
创建Socket时，请勿使用第3和第4个参数。没有真正需要指定本地地址，缺少VPN，除了作为netadmin的想象力之外，没有真正需要指定本地端口。
ServerSocket应该将其Socket连接的结尾发送到一个本地端口而不是它正在侦听的端口。
不，不。所有接受的套接字都使用与侦听端口相同的本地端口。