MVC Application

You can initiate the project through Spring Initializr

MVC App Spring Initializr

This application will use:

Project: Maven
Programming Langauge: Java
Spring Boot: 3.2.0(M3) -> It's recommended to use stable version, but you still can use SNAPSHOT (it's version under development or experimental probably).
Dependencies:
- Spring Web: to enable build Web, RESTful API, and Apache Tomcat as an default embedded container
- Spring Boot DevTools: to enable hot reload the application without kill the application (you might need some configuration in different text editor)
- Spring Boot Starter Test: to enable integration with Java Test

First Common APIs

java

package com.alibaihaqi.springboot.mvcapp.common;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class CommonController {

    @RequestMapping("common")
    @ResponseBody
    public String commonResponse() {
        return "Hello!";
    }
}

Generate simple HTML file

You can use StringBuffer to generate the HTML but it really painful by append it one-by-one.

[With StringBuffer]

java

package com.alibaihaqi.springboot.mvcapp.common;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class CommonController {
    @RequestMapping("common-html")
    @ResponseBody
    public String commonHtmlResponse() {
        StringBuffer sb = new StringBuffer();
        sb.append("<html>");
        sb.append("<head>");
        sb.append("<title>MVC App</title>");
        sb.append("</head>");
        sb.append("<body>");
        sb.append("<p>My MVC App</p>");
        sb.append("</body>");
        sb.append("</html>");
        return sb.toString();
    }
}

Use Apache Tomcat Embed

By using Apache Tomcat Embed package, you can move your HTML file as an independent page.

You can setup by install the dependency through pom.xml

xml

<dependencies>
	<dependency>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-web</artifactId>
	</dependency>
	<dependency>
		<groupId>org.apache.tomcat.embed</groupId>
		<artifactId>tomcat-embed-jasper</artifactId>
	</dependency>
</dependencies>

Add the prefix and suffix information as a relative path for asset locations

properties

spring.mvc.view.prefix=/WEB-INF/jsp/
spring.mvc.view.suffix=.jsp

Add your first JSP file, for example your file on this path /src/main/resources/META-INF/resources/WEB-INF/jsp/commonJsp.jsp

html

<html>
    <head>
        <title>MVC App</title>
    </head>
    <body>
        <p>My MVC App</p>
    </body>
</html>

Implement it on your Controller

java

package com.alibaihaqi.springboot.mvcapp.common;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class CommonController {

    // We remove @ResponseBody to indicate the Spring Boot
    // that we want to serve other resources, such as JSP file
    // commonJsp will refer as the view name
    @RequestMapping("common-jsp")
    public String commonJspResponse() {
        return "commonJsp";
    }
}

Query Parameters

In the browser, you can add query param in the end of the URL page. For example, http://www.example.com/somepage?d=20231018 where http://www.example.com/somepage is the page you want to access, and d=20231018 is the query param append to the URL.

You need to specifically input in the controller of the page.

Required ParamsOptional Params

java

@Controller
public class LoginController {

    // Use Logger instead of System.out.println or else in Production
    // So, we can control from application.properties which level should be printed in the development
    // and production
    private Logger logger = LoggerFactory.getLogger(getClass());

    @RequestMapping("login")
    // In this case, you want to explicitly tell the page that you require the page to add param `name` in the URL
    // or you will give the response 400
    public String loginPage (@RequestParam String name, ModelMap model) {
        System.out.println("Request param is " + name); // NOT RECOMMENDED FOR PRODUCTION
        logger.debug("Request param is {}", name);
        // You want to inject the param to the HTML page
        model.put("name", name);
        return "loginJsp";
    }
}

java

@Controller
public class LoginController {

    // Use Logger instead of System.out.println or else in Production
    // So, we can control from application.properties which level should be printed in the development
    // and production
    private Logger logger = LoggerFactory.getLogger(getClass());

    @RequestMapping("login")
    // In this case, you will process some logic if query params appear in the URL
    public String loginPage (@RequestParam(required=false) String name, ModelMap model) {
        System.out.println("Request param is " + name); // NOT RECOMMENDED FOR PRODUCTION
        logger.debug("Request param is {}", name);
        // You want to inject the param to the HTML page (if available)
        model.put("name", name);
        return "loginJsp";
    }
}

Here is the example when you put the required param in the code but the param is missing.

Param Missing

For logging, Spring Boot Starter Web is already included logging dependency called spring-boot-starter-logging with default Logback with SLF4j

MVC Application ​

First Common APIs ​

Generate simple HTML file ​

Use Apache Tomcat Embed ​

Query Parameters ​

MVC Application

First Common APIs

Generate simple HTML file

Use Apache Tomcat Embed

Query Parameters