这里我有两个类ClientToSendCalculable.java
import java.io.*;
import java.net.*;
public class ClientToSendCalculable implements Serializable
{
public ClientToSendCalculable(int port)
{
try
(
Socket s = new Socket("localhost", port);
ObjectOutputStream writer = new ObjectOutputStream(s.getOutputStream());
ObjectInputStream reader = new ObjectInputStream(s.getInputStream());
)
{
System.out.println("Connection was established!");
ClientToSendCalculable.Addition addition = new ClientToSendCalculable.Addition();
addition.firstAddendum = 5;
addition.secondAddendum = 7;
writer.writeObject(addition);
double res = (Double)reader.readObject();
System.out.println(res);
}
catch(Exception e)
{
e.printStackTrace();
}
}
private class Addition implements Calculable, Serializable
{
private double firstAddendum, secondAddendum;
public double calc()
{
return firstAddendum + secondAddendum;
}
}
public static void main(String[] args)
{
new ClientToSendCalculable(7777);
}
}
和ServerToGetCalculable.java
import java.io.*;
import java.net.*;
public class ServerToGetCalculable
{
public ServerToGetCalculable(int port)
{
try
(
ServerSocket ss = new ServerSocket(port);
Socket s = ss.accept();
ObjectOutputStream writer = new ObjectOutputStream(s.getOutputStream());
ObjectInputStream reader = new ObjectInputStream(s.getInputStream());
)
{
System.out.println("Got a client!");
Calculable calcObj = (Calculable)reader.readObject();
double res = calcObj.calc();
writer.writeObject(res);
}
catch(Exception e)
{
e.printStackTrace();
}
}
public static void main(String[] args)
{new ServerToGetCalculable(7777);}
}
我的问题是ClientToSendCalculable.java为什么要实现Serializable?我只通过Socket发送其内部类Addition.java,但没有单独发送ClientToSendCalculable.java。这就是为什么在我看来,仅Addition.java是可序列化的就足够了,但是如果我将ClientToSendCalculable.java设置为不是可序列化的,我将得到一个异常,试图执行以下代码行:
writer.writeObject(addition);
最佳答案
Addition.java是一个内部类(非静态)->它包含一个字段,该字段保存对封闭的ClientToSendCalculable实例的引用->该外部类的字段必须进行序列化->它必须实现Serializable接口。