A lightweight WEB Framework for java

the classes have to be in the same package wich is define in web.xml as package_src init-parameter

    <servlet>
        <servlet-name>merana</servlet-name>
        <servlet-class>ambovombe.merana.servlet.MeranaServlet</servlet-class>
        <init-param>
            <param-name> package_src </param-name>
            <param-value>com.example.demo.model</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>merana</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>  

• If you want to control Cors access policy you should add the following code to your project and define it in the web.xml file as following

import jakarta.servlet.*;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CorsFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletResponse httpResponse = (HttpServletResponse) response;

        // Allow requests from any origin. You can restrict this to specific origins.
        httpResponse.setHeader("Access-Control-Allow-Origin", "http://localhost:3000");

        // Allow the following HTTP methods.
        httpResponse.setHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");

        // Allow the following headers.
        httpResponse.setHeader("Access-Control-Allow-Headers", "Content-Type, Authorization");

        // Allow credentials (e.g., cookies).
        httpResponse.setHeader("Access-Control-Allow-Credentials", "true");

        chain.doFilter(request, response);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        // Initialization code if needed.
    }

    @Override
    public void destroy() {
        // Cleanup code if needed.
    }
}

• And add it in the web xml file as follow

    <filter>
        <filter-name>CorsFilter</filter-name>
        <filter-class>com.example.demo.cors.CorsFilter</filter-class> <!-- Update with the correct package and class name -->
    </filter>
    <filter-mapping>
        <filter-name>CorsFilter</filter-name>
        <url-pattern>/*</url-pattern> <!-- This allows the filter to intercept all requests -->
    </filter-mapping>

• the Url will be defined with the annotation @RequestUrl or the class or @Url for the method
• the @Url annotation will have a type method to define the method of the http request
  • Example

  @RequestUrl("/example")
  public class Test {
    @Url(method = GET)                     // the link to this function will be .../example within the method GET
    public ModelView getMethod(){
      // do something...
    }
  
    @Url(value = "/save", method = POST)    // the link to this function will be .../example/save within the method POST
    public ModelView postMethod(){
      // do something
    }
  }

• TO pass formData parameter you use the annotation @Param(value = "...")
• To pass data from a body you use the annotation @RequestBody
  • Example

  @RequestUrl("/example")
  public class Test {
    @Url(method = PUT)                     // the link to this function will be .../example within the method PUT
    public Object getMethod(@RequestBody ExampleObject example){
      // do something...
    }
  
    @Url(value = "/save", method = POST)    // the link to this function will be .../example/save within the method POST
    public ModelView postMethod(@Param("name") String name){
      // do something
    }
  }

• functions must return Modelview
• Within the Modelview you can define the view jsp file to show and send data to this view
  • Example

      Modelview modelview = new Modelview();
      modelview.setView("index.jsp");
      modelview.addItem("data", "Test");

• You can also put argument in the function and defnie it by post or get method
• And do the same thing with classes property
  • Example

        public class Test {
            String name;
            @Url("/tests")
            public Modelview tests(String ok){
                Modelview modelview = new Modelview();
                if(getName() != null)
                    modelview.addItem("test1", getName());
                else modelview.addItem("test1", "unknown");
                modelview.addItem("test2", ok);
                modelview.setView("ox.jsp");
                return modelview;
            }
        }

• when the Url annoted method return anything else than ModelView it will return a JSON
  • Example

  @Url(method = POST)
  public Commune save(@RequestBody Commune commune){
      // Do something...
      return commune;
  }

• There is an authentification function that could be configured in the web.xml as following:
• By adding as init-param a session_name and a session_profil where the session name will be the name of the boolean value within the session that says if it could be used or not.
• And session_profil the name of the value within the session that contain the profile type

    <servlet>
        <servlet-name>frontservlet</servlet-name>
        <servlet-class>etu1999.framework.servlet.FrontServlet</servlet-class>
        <init-param>
            <param-name>package_src</param-name>
            <param-value>controller</param-value>
        </init-param>
        <init-param>
            <param-name>session_name</param-name>
            <param-value>isConnected</param-value>
        </init-param>
        <init-param>
            <param-name>session_profile</param-name>
            <param-value>profil</param-value>
        </init-param>
    </servlet>

• An example of utilisation:

@Url("/login")
    public Modelview signin(){
        Modelview modelview = new Modelview();
        modelview.setView("login.jsp");

        return modelview;
    }
    
    @Url("/signin")
    public Modelview login(String username, String password){
        Modelview modelview = new Modelview();

        if(username.equals("rakharrs") && password.equals("pixel")){
            modelview.addSession( "isConnected" , true );
			modelview.addSession( "profil" , "admin" );
        }else if(username.equals("scott") && password.equals("tiger")){
            modelview.addSession( "isConnected" , true );
			modelview.addSession( "profil" , "guest" );
        }

        modelview.setView("authed.jsp");

        return modelview;
    }

    @Auth(user = "admin")
    @Url("/limited")
    public Modelview limited(){
        Modelview modelview = new Modelview();
        modelview.setView("admin.jsp");
        return modelview;
    }

• There in the login page, it's just a normal login, in the signin (which is the page processing) it verify the credentials and put in the session the value
• The if a user want to access /limited page it will only be displayed if the user is authentified as an admin profil