Java 用于发送和接收用户定义对象的套接字程序不工作
我有一个用户定义的类消息,我想在客户端和服务器之间传递它的对象 消息类如下所示:Java 用于发送和接收用户定义对象的套接字程序不工作,java,sockets,object,serializable,Java,Sockets,Object,Serializable,我有一个用户定义的类消息,我想在客户端和服务器之间传递它的对象 消息类如下所示: import java.io.Serializable; public class Message implements Serializable { String CorS; int data_id; int status_id; Integer value; boolean withdraw; public Message() { Co
import java.io.Serializable;
public class Message implements Serializable
{
String CorS;
int data_id;
int status_id;
Integer value;
boolean withdraw;
public Message()
{
CorS = null;
data_id = 0;
status_id = 0;
value = 0;
withdraw = false;
}
public Message(String CorS, int data_id, int status_id, Integer value)
{
this.CorS = CorS;
this.data_id = data_id;
this.status_id = status_id;
this.value = value;
}
public Message(boolean withdraw)
{
this.withdraw = withdraw;
}
}
Socket s = null;
ObjectInputStream in = null;
ObjectOutputStream out = null;
String hostname = null;
int port_no = 0;
HashMap<String, Integer> map = null;
Message m = null;
map = servers.get("Server" + server);
for(String key : map.keySet())
{
hostname = key;
port_no = map.get(key);
}
//System.out.println(hostname + " " + port_no);
s = new Socket(hostname, port_no);
in = new ObjectInputStream(new BufferedInputStream(s.getInputStream()));
out = new ObjectOutputStream(new BufferedOutputStream(s.getOutputStream()));
s_now = s;
m = new Message(client, data, 0, 0);
out.writeObject(m);
out.flush();
System.out.println("Sent obj");
while (true)
{
try
{
System.out.println("Waiting for client on port " + serverSocket.getLocalPort() + "...");
Socket server = serverSocket.accept();
System.out.println("Just connected to " + server.getRemoteSocketAddress());
ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(server.getInputStream()));
//ObjectOutputStream out = new ObjectOutputStream(server.getOutputStream());
Message m = (Message) in.readObject();
System.out.println(m.value);
}
catch (IOException e)
{
e.printStackTrace();
break;
}
catch (ClassNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Waiting for client on port 1051...
Just connected to /127.0.0.1:59216
将对象发送到服务器的客户端中的代码如下:
import java.io.Serializable;
public class Message implements Serializable
{
String CorS;
int data_id;
int status_id;
Integer value;
boolean withdraw;
public Message()
{
CorS = null;
data_id = 0;
status_id = 0;
value = 0;
withdraw = false;
}
public Message(String CorS, int data_id, int status_id, Integer value)
{
this.CorS = CorS;
this.data_id = data_id;
this.status_id = status_id;
this.value = value;
}
public Message(boolean withdraw)
{
this.withdraw = withdraw;
}
}
Socket s = null;
ObjectInputStream in = null;
ObjectOutputStream out = null;
String hostname = null;
int port_no = 0;
HashMap<String, Integer> map = null;
Message m = null;
map = servers.get("Server" + server);
for(String key : map.keySet())
{
hostname = key;
port_no = map.get(key);
}
//System.out.println(hostname + " " + port_no);
s = new Socket(hostname, port_no);
in = new ObjectInputStream(new BufferedInputStream(s.getInputStream()));
out = new ObjectOutputStream(new BufferedOutputStream(s.getOutputStream()));
s_now = s;
m = new Message(client, data, 0, 0);
out.writeObject(m);
out.flush();
System.out.println("Sent obj");
while (true)
{
try
{
System.out.println("Waiting for client on port " + serverSocket.getLocalPort() + "...");
Socket server = serverSocket.accept();
System.out.println("Just connected to " + server.getRemoteSocketAddress());
ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(server.getInputStream()));
//ObjectOutputStream out = new ObjectOutputStream(server.getOutputStream());
Message m = (Message) in.readObject();
System.out.println(m.value);
}
catch (IOException e)
{
e.printStackTrace();
break;
}
catch (ClassNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Waiting for client on port 1051...
Just connected to /127.0.0.1:59216
问题是对象没有打印出来。我得到的结果如下:
import java.io.Serializable;
public class Message implements Serializable
{
String CorS;
int data_id;
int status_id;
Integer value;
boolean withdraw;
public Message()
{
CorS = null;
data_id = 0;
status_id = 0;
value = 0;
withdraw = false;
}
public Message(String CorS, int data_id, int status_id, Integer value)
{
this.CorS = CorS;
this.data_id = data_id;
this.status_id = status_id;
this.value = value;
}
public Message(boolean withdraw)
{
this.withdraw = withdraw;
}
}
Socket s = null;
ObjectInputStream in = null;
ObjectOutputStream out = null;
String hostname = null;
int port_no = 0;
HashMap<String, Integer> map = null;
Message m = null;
map = servers.get("Server" + server);
for(String key : map.keySet())
{
hostname = key;
port_no = map.get(key);
}
//System.out.println(hostname + " " + port_no);
s = new Socket(hostname, port_no);
in = new ObjectInputStream(new BufferedInputStream(s.getInputStream()));
out = new ObjectOutputStream(new BufferedOutputStream(s.getOutputStream()));
s_now = s;
m = new Message(client, data, 0, 0);
out.writeObject(m);
out.flush();
System.out.println("Sent obj");
while (true)
{
try
{
System.out.println("Waiting for client on port " + serverSocket.getLocalPort() + "...");
Socket server = serverSocket.accept();
System.out.println("Just connected to " + server.getRemoteSocketAddress());
ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(server.getInputStream()));
//ObjectOutputStream out = new ObjectOutputStream(server.getOutputStream());
Message m = (Message) in.readObject();
System.out.println(m.value);
}
catch (IOException e)
{
e.printStackTrace();
break;
}
catch (ClassNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Waiting for client on port 1051...
Just connected to /127.0.0.1:59216
在这方面的任何帮助都将不胜感激。谢谢:)您需要在两端的
ObjectInputStream
之前创建ObjectOutputStream
原因是,正如Javadoc中所描述的,相应的构造函数写入和读取流头。因此,在对等方的输出流构造函数执行之前,输入流构造函数无法返回。因此,如果您先构造两个输入流,就会出现死锁。谢谢。成功了。但是你能告诉我为什么会这样吗?有什么合理的解释吗?