WEB SERVICES: Restful Calculator Basic ~ Thế Giới Giải Mã

29 December 2016

WEB SERVICES: Restful Calculator Basic

By Admin at 12:29:00 AM JAVA Web Services No comments

Demo Calculator Add Subtract

=============PHẦN WEB SERVICE =============

@Path("/add")
@GET
@Produces("text/plain")
public String add(
        @DefaultValue("5") @QueryParam("num1") double num1,
        @DefaultValue("3") @QueryParam("num2") double num2) {
    double result = num1 + num2;
    return "Ket qua phep cong: " + result;
}

@Path("/subtract")
@GET
@Consumes("text/plain")
public String subtract(
        @QueryParam("num1") double num1,
        @QueryParam("num2") double num2) {
    double result = num1 + num2;
    return "Ket qua phep tru: " + result;
}

Clean and Build > Deploy > Run project Restful-001

http://localhost:8080/Restful-001/webresources/generic

http://localhost:8080/Restful-001/webresources/generic/add

http://localhost:8080/Restful-001/webresources/generic/add?num1=6&num2=8

http://localhost:8080/Restful-001/webresources/generic/subtract?num1=6&num2=8

===============PHẦN WEB CLIENT==============

Tạo trang Calculator.jsp

Calculator.jsp

Java Web Service 2016

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1>Hello World!</h1>
        <form action="CalculatorServlet">
            Num1: <input type="text" name="num1" value="" /><br/>
            Num2: <input type="text" name="num2" value="" /><br/>
            <input type="submit" value="Add" name="action" />
            <input type="submit" value="Sub" name="action"/>
        </form>
    </body>
</html>

Tạo Servlet CalculatorServlet

CalculatorServlet.java

Java Web Service 2016

package servlet;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.core.util.MultivaluedMapImpl;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.ws.rs.core.MultivaluedMap;

/**
 *
 * @author Lonely
 */
public class CalculatorServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        
        String action = request.getParameter("action");
        String num1 = request.getParameter("num1");
        String num2 = request.getParameter("num2");
        String uri = "http://localhost:8080/Restful-001/webresources/generic";
        
        Client client = Client.create(); //Add jersey-client-1.19.jar
        client.setFollowRedirects(Boolean.TRUE);
        WebResource resource = client.resource(uri);
        
        MultivaluedMap<String, String> params = new MultivaluedMapImpl(); //Add jersey-core-1.19.jar
        params.add("num1", num1);
        params.add("num2", num2);
        
        if ("Add".equalsIgnoreCase(action)) {
            //res hiển thị nột dung bên trong method add của server
            String res = resource.path("add").queryParams(params).get(String.class);
            out.print("Add: "+num1+" + "+num2+" "+res +" <a href="+"Calculator.jsp"+"><input type="+"button"+" value="+"Calculator"+"></a>");
        } else if ("Sub".equalsIgnoreCase(action)) {
            //res hiển thị nột dung bên trong method subtract của server
            String res = resource.path("subtract").queryParams(params).get(String.class);
            out.print("Add: "+num1+" - "+num2+" "+res +" <a href="+"Calculator.jsp"+"><input type="+"button"+" value="+"Calculator"+"></a>");
        }
    }

}