【发布时间】：2019-08-15 20:03:58
【问题描述】：
我正在编写（测试）一个简单的客户端-服务器应用程序，我需要通过套接字的 ObjectOutputStream 发送一些对象，然后通过套接字的 ObjectInputStream 读取它。问题是 ObjectOutputStream writeObject 方法不能正常工作（或者我做错了什么......）。我正在用同样的方法写作和阅读。
java-版本：
java version "1.8.0_201"
Java(TM) SE Runtime Environment (build 1.8.0_201-b09)
Java HotSpot(TM) 64-Bit Server VM (build 25.201-b09, mixed mode)
这是我的代码：
ServerTest.java
ExecutorService tp = Executors.newFixedThreadPool(2);
public ServerTest(String info) {
System.out.println("SERVER TEST HAVE BEEN STARTED FROM " + info);
try {
System.out.println("Starting server ...");
tp.submit(new ServerTask());
System.out.println("Server started ...");
Thread.sleep(1000);
System.out.println("Starting client ...");
tp.submit(new Client(new Socket("localhost", 3333)));
System.out.println("Client started at localhost on port 3333 ...");
} catch (IOException | InterruptedException ex) {
Logger.getLogger(ServerTest.class.getName()).log(Level.SEVERE, null, ex);
}
}
public static void main(String[] args) {
try {
new ServerTest("SERVER TEST MAIN STATIC METHOD");
Thread.sleep(100000);
} catch (InterruptedException ex) {
Logger.getLogger(ServerTest.class.getName()).log(Level.SEVERE, null, ex);
}
}
ClientTask.java（实现 Runnable）
private Socket socket;
private ObjectOutputStream oos;
private ObjectInputStream ois;
public ClientTask(Socket socket) {
System.out.println("CLIENT TASK SOCKET : " + socket);
this.socket = socket;
try {
oos = new ObjectOutputStream(socket.getOutputStream());
oos.flush();
ois = new ObjectInputStream(socket.getInputStream());
} catch (IOException ex) {
Logger.getLogger(ClientTask.class.getName()).log(Level.SEVERE, null, ex);
}
}
@Override
public void run() {
System.out.println("client task running ...");
for (int i = 0; i < 1; i++) {
try {
Thread.sleep(1000);
SimpleObject so = new SimpleObject(100, "test_str");
System.out.println("Trying to serialize object into output stream...");
System.out.println("Object to be written " + so.toString());
oos.writeObject(so);
oos.flush();
System.out.println("Check if the object had been serialized properly ...");
System.out.println("Bytes in stream : " + ois.available());
if (ois.available() <= 0) {
System.out.println("Object had not been serialized ...");
continue;
}
System.out.println("Trying to deserialize object from input stream ...");
SimpleObject desObj = (SimpleObject) ois.readObject();
System.out.println("Read object: " + desObj.toString());
System.out.println("Aborting from method ...");
} catch (InterruptedException ex) {
Logger.getLogger(ClientTask.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(ClientTask.class.getName()).log(Level.SEVERE, null, ex);
} catch (ClassNotFoundException ex) {
Logger.getLogger(ClientTask.class.getName()).log(Level.SEVERE, null, ex);
} finally {
try {
ois.close();
oos.close();
} catch (IOException ex) {
Logger.getLogger(ClientTask.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
System.out.println("Exiting client task ...");
}
ServerTask.java（实现可运行）
ExecutorService tp = Executors.newFixedThreadPool(10);
@Override
public void run() {
System.out.println("Server task run start ...");
try {
ServerSocket ss = new ServerSocket(3333);
for (;;) {
System.out.println("Server socket start ...");
Socket s = ss.accept();
s.setSoTimeout(0);
System.out.println("Connection: " + s.getInetAddress().toString() + " " + s.getPort());
System.out.println("Starting client task ...");
tp.submit(new ClientTask(s));
System.out.println("Client task started ...");
System.out.println("Server socket end ...");
}
} catch (IOException ex) {
ex.printStackTrace();
}
System.out.println("Server task run end ...");
}
Client.java（实现可运行）
private Socket socket;
private ObjectOutputStream oos;
private ObjectInputStream ois;
public Client(Socket socket) {
System.out.println("CLIENT SOCKET : " + socket.toString());
this.socket = socket;
try {
oos = new ObjectOutputStream(socket.getOutputStream());
oos.flush();
ois = new ObjectInputStream(socket.getInputStream());
} catch (IOException ex) {
Logger.getLogger(ClientTask.class.getName()).log(Level.SEVERE, null, ex);
}
}
@Override
public void run() {
for (int i = 0; i < 10; i++) {
//System.out.println("client running ...");
try {
Thread.sleep(1000);
} catch (InterruptedException ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
SimpleObject.java（实现可序列化）
private static final long serialVersionUID = 4L;
private Integer integer;
private String string;
public SimpleObject(Integer integer, String string) {
this.integer = integer;
this.string = string;
}
//getters,setters, toString method ...
输出是
run:
SERVER TEST HAVE BEEN STARTED FROM SERVER TEST MAIN STATIC METHOD
Starting server ...
Server started ...
Server task run start ...
Server socket start ...
Starting client ...
CLIENT SOCKET : Socket[addr=localhost/127.0.0.1,port=3333,localport=57703]
Connection: /127.0.0.1 57703
Starting client task ...
CLIENT TASK SOCKET : Socket[addr=/127.0.0.1,port=57703,localport=3333]
Client started at localhost on port 3333 ...
Client task started ...
Server socket end ...
Server socket start ...
client task running ...
Trying to serialize object into output stream...
Object to be written SimpleObject{integer=100, string=test_str}
Check if the object had been serialized properly ...
Bytes in stream : 0
Object had not been serialized ...
Exiting client task ...
这是一个简单的应用程序，但它不起作用......我不明白为什么。请帮帮我。
【问题讨论】：
-
你的对象
SimpleObject是否实现了Serializable接口。 -
@VinayAvasthi 是的。
-
System.out.println("Bytes in stream : " + ois.available()); 行，显示的是客户端任务的 Socket 输入流的字节数。这将显示服务器发送的可用字节数，这与写入套接字输出流的内容无关。
-
另外，您是否希望客户端和服务器都使用相同的输入流？我希望客户端和服务器位于不同的线程上（或者，在不同的 java 进程中），在这种情况下，客户端输出流将映射到服务器输入流，而客户端输入流将映射到服务器输出流。这是一个很好的例子：baeldung.com/a-guide-to-java-sockets（注意：这并不意味着支持 Baeldun。但这个例子很好。）
-
@ThomasBitonti 我将对象的写入和读取都写到了一种方法中，只是为了便于测试……但是现在，我尝试将其拆分为不同的线程（和类）并且它可以工作。非常感谢您，如果您将您的评论作为答案发表，我会将其标记为已接受的答案。
标签： java sockets objectoutputstream