<servlet>
    <servlet-name>Server_side_code</servlet-name>
    <servlet-class>com.hmkcode.servlet.Server_side_codeServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>Server_side_code</servlet-name>
    <url-pattern>/server_side_code</url-pattern>
</servlet-mapping>
<welcome-file-list>
    <welcome-file>index.html</welcome-file>
</welcome-file-list>




Servlet代码

public class Server_side_codeServlet  extends HttpServlet{
    private static final long serialVersionUID = 1L;

    // This will store all received articles
    List<Person> persons = new LinkedList<Person>();

    /***************************************************
     * URL: /
     * doPost(): receives JSON data, parse it, map it and send back as JSON
     ****************************************************/
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException{

        // 1. get received JSON data from request
        BufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream()));
        String json = "";
        if(br != null){
            json = br.readLine();
        }

        // 2. initiate jackson mapper
        ObjectMapper mapper = new ObjectMapper();

        // 3. Convert received JSON to Article
        Person person = mapper.readValue(json, Person.class);

        // 4. Set response type to JSON
        response.setContentType("application/json");

        // 5. Add article to List<Article>
        if(persons.size() > 20)
            persons.remove(0);

        persons.add(person);

        // 6. Send List<Article> as JSON to client
        mapper.writeValue(response.getOutputStream(), persons);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {

        //2. initiate jackson mapper
        ObjectMapper mapper = new ObjectMapper();


        // 4. Set response type to JSON
        resp.setContentType("application/json");


        // 6. Send List<Article> as JSON to client
        mapper.writeValue(resp.getOutputStream(), persons);
    }
}


我在Android中制作了一个简单的应用程序,从该应用程序我将三个参数发送到服务器。从android方面来看,它工作正常,没有错误。但是当我尝试
在本地主机上访问它:8888,它显示错误
HTTP错误:503
问题访问/。原因:
暂停服务
由Jetty://提供技术支持

最佳答案

这是因为您的应用程序可能已关闭,或者该应用程序试图访问未启动并正在运行的服务器。

请参见reference to 503 http status。检查以下内容

1. your server is up and running
2. your host mapping is right and points to right ip
3. your localhost server is configured to respond at the post specified.

10-08 03:14