package test;import java.io.ObjectOutputStream;import java.net.HttpURLConnection;import java.net.URL;public class Test {public static void main(String[] args) {    URL url;    try {        url = new URL("http://localhost:8081/Projectt/ServletTest");        HttpURLConnection conn = (HttpURLConnection) url.openConnection();        conn.setDoOutput(true);        conn.setRequestMethod("POST");        ObjectOutputStream out = new ObjectOutputStream(conn.getOutputStream());        out.writeObject("test");        out.flush();        System.out.println("------------");    } catch (Exception e) {        // TODO Auto-generated catch block        e.printStackTrace();    }}}這是我的servlet代碼import java.io.IOException;import java.io.ObjectInputStream;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet("/ServletTest")public class ServletTest extends HttpServlet {     private static final long serialVersionUID = 1L;     public ServletTest() {         super();     }protected void doGet(HttpServletRequest request, HttpServletResponse response)        throws ServletException, IOException {    doPost(request,response);}protected void doPost(HttpServletRequest request, HttpServletResponse response)        throws ServletException, IOException {    ObjectInputStream in = new ObjectInputStream(request.getInputStream());    try {        System.out.println("In get : " + (String) in.readObject());    } catch (ClassNotFoundException e) {        e.printStackTrace();    }    System.out.println("End of servlet");}}我想從Java代碼中調用servlet。以上是我的代碼。端口為8081。給定的URL是從瀏覽器中觸發的，而不是從我的代碼中觸發的。僅從Test類而不是從TestServlet執行println語句