Java服务器客户端连接问题

我已经为此工作了一段时间，但似乎无法让它工作。我有一个服务器，当客户端发送请求时，它会向客户端发送响应。但是，即使服务器接收并处理请求，它似乎也没有发送响应

服务器类

import java.io.*;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;

import com.sun.net.httpserver.*;

public class Server implements HttpHandler
{

    Server()
    {
    }

    public static void main(String[] args) throws Exception 
    {
        //starts server
        HttpServer server = HttpServer.create(new InetSocketAddress(8000), 0);

        server.createContext("/", new Server());
        server.setExecutor(null); // creates a default executor
        server.start();
    }

    public void handle(HttpExchange exchange) throws IOException 
    {
        //request info
        Headers requestHeaders = exchange.getRequestHeaders();

        boolean getItems = requestHeaders.get("RequestType").get(0).equals("getItems");

        //calls the handler method for getItems
        if(getItems)
        {
            try {
                handleGetItemsRequest(exchange);
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    //handle a request to get all points
    public void handleGetItemsRequest(HttpExchange exchange) throws IOException, ClassNotFoundException
    {
        System.out.println("Get Items");

        String response = "Here's all of the items";

        ByteArrayOutputStream b = new ByteArrayOutputStream();
        ObjectOutputStream o = new ObjectOutputStream(b);
        o.writeObject(response);
        o.close();
    }

    /*public static byte[] serialize(Object obj) throws IOException {
        ByteArrayOutputStream b = new ByteArrayOutputStream();
        ObjectOutputStream o = new ObjectOutputStream(b);
        o.writeObject(obj);
        return b.toByteArray();
    }*/

    public static Object deserialize(byte[] bytes) throws IOException, ClassNotFoundException {
        ByteArrayInputStream b = new ByteArrayInputStream(bytes);
        ObjectInputStream o = new ObjectInputStream(b);
        return o.readObject();
    }

}

import java.awt.List;
import java.io.*;
import java.net.*;
import java.util.ArrayList;

public class GetItems {

    public static void main(String [] args) throws ClassNotFoundException{
        try {
            URL url = new URL("http://localhost:8000/");
            HttpURLConnection connection = (HttpURLConnection)url.openConnection();
            connection.setRequestProperty("RequestType", "getItems");
            connection.connect();


            BufferedReader in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String inputLine;

            inputLine = in.readLine();
            System.out.println(inputLine);
            in.close();

        }catch(MalformedURLException e){
            e.printStackTrace();
        }catch(IOException e){
            e.printStackTrace();
        }

    }

    public static Object deserialize(byte[] string) throws IOException, ClassNotFoundException {
        ByteArrayInputStream b = new ByteArrayInputStream(string);
        ObjectInputStream o = new ObjectInputStream(b);
        return o.readObject();
 }
}

客户端类

import java.io.*;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;

import com.sun.net.httpserver.*;

public class Server implements HttpHandler
{

    Server()
    {
    }

    public static void main(String[] args) throws Exception 
    {
        //starts server
        HttpServer server = HttpServer.create(new InetSocketAddress(8000), 0);

        server.createContext("/", new Server());
        server.setExecutor(null); // creates a default executor
        server.start();
    }

    public void handle(HttpExchange exchange) throws IOException 
    {
        //request info
        Headers requestHeaders = exchange.getRequestHeaders();

        boolean getItems = requestHeaders.get("RequestType").get(0).equals("getItems");

        //calls the handler method for getItems
        if(getItems)
        {
            try {
                handleGetItemsRequest(exchange);
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    //handle a request to get all points
    public void handleGetItemsRequest(HttpExchange exchange) throws IOException, ClassNotFoundException
    {
        System.out.println("Get Items");

        String response = "Here's all of the items";

        ByteArrayOutputStream b = new ByteArrayOutputStream();
        ObjectOutputStream o = new ObjectOutputStream(b);
        o.writeObject(response);
        o.close();
    }

    /*public static byte[] serialize(Object obj) throws IOException {
        ByteArrayOutputStream b = new ByteArrayOutputStream();
        ObjectOutputStream o = new ObjectOutputStream(b);
        o.writeObject(obj);
        return b.toByteArray();
    }*/

    public static Object deserialize(byte[] bytes) throws IOException, ClassNotFoundException {
        ByteArrayInputStream b = new ByteArrayInputStream(bytes);
        ObjectInputStream o = new ObjectInputStream(b);
        return o.readObject();
    }

}

import java.awt.List;
import java.io.*;
import java.net.*;
import java.util.ArrayList;

public class GetItems {

    public static void main(String [] args) throws ClassNotFoundException{
        try {
            URL url = new URL("http://localhost:8000/");
            HttpURLConnection connection = (HttpURLConnection)url.openConnection();
            connection.setRequestProperty("RequestType", "getItems");
            connection.connect();


            BufferedReader in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String inputLine;

            inputLine = in.readLine();
            System.out.println(inputLine);
            in.close();

        }catch(MalformedURLException e){
            e.printStackTrace();
        }catch(IOException e){
            e.printStackTrace();
        }

    }

    public static Object deserialize(byte[] string) throws IOException, ClassNotFoundException {
        ByteArrayInputStream b = new ByteArrayInputStream(string);
        ObjectInputStream o = new ObjectInputStream(b);
        return o.readObject();
 }
}

---

问题在于，在服务器类中，handleGetItemRequest创建了一个新的outputStream，而不是使用HttpExchange对象提供的outputStream。 请参阅，您可以使用exchange.getResponseBody（），它提供了一个OutputStream，您可以在创建ObjectOutputStream时将其用作参数

ObjectOutputStream o = new ObjectOutputStream(exchange.getResponseBody());