New project using Spring MVC 5 in eclipse, but I am having error 404

Question

I am new to Spring MVC and I am trying to make simple HelloWorld program i am following this tutorial https://www.javaguides.net/2018/10/spring-mvc-5-hello-world-example.html

package main.java.config;


import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {
"main.java"
})
public class AppConfig {

@Bean
public InternalResourceViewResolver resolver() {
    InternalResourceViewResolver resolver = new InternalResourceViewResolver();
    resolver.setViewClass(JstlView.class);
    resolver.setPrefix("/WEB-INF/views/");
    resolver.setSuffix(".jsp");
    return resolver;
}
}

package main.java.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class ServletDispatcherInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

@Override
protected Class <?> [] getRootConfigClasses() {
    // TODO Auto-generated method stub
    return null;
}

@Override
protected Class <?> [] getServletConfigClasses() {
    return new Class[] {
        AppConfig.class
    };
}

@Override
protected String[] getServletMappings() {
    return new String[] {
        "/"
    };
}
}

package main.java.controller;

import java.time.LocalDateTime;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import main.java.model.HelloWorld;

@Controller
public class JavaController {

@RequestMapping("/helloworld")
public String handler(Model model) {

    HelloWorld helloWorld = new HelloWorld();
    helloWorld.setMessage("Hello World Example Using Spring MVC 5!!!");
    helloWorld.setDateTime(LocalDateTime.now().toString());
    model.addAttribute("helloWorld", helloWorld);
    return "helloworld";
}
}

package main.java.model;

public class HelloWorld {
private String message;
private String dateTime;
public String getMessage() {
    return message;
}
public void setMessage(String message) {
    this.message = message;
}
public String getDateTime() {
    return dateTime;
}
public void setDateTime(String dateTime) {
    this.dateTime = dateTime;
}
}

...
      ${helloWorld.message}</h2>
      Server date time is : ${helloWorld.dateTime}
...

i tried cleaning the server, close and open the browser, republish my project.

I don't know what to do now, please help me.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>SpringMVC5</groupId>
  <artifactId>SpringMVC5</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>

 <name>springmvc5-helloworld-exmaple Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <properties>
   <failOnMissingWebXml>false</failOnMissingWebXml>
    </properties>
    <dependencies>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.1.0.RELEASE</version>
    </dependency>

    <!-- JSTL Dependency -->
    <dependency>
        <groupId>javax.servlet.jsp.jstl</groupId>
        <artifactId>javax.servlet.jsp.jstl-api</artifactId>
        <version>1.2.1</version>
    </dependency>
    <dependency>
        <groupId>taglibs</groupId>
        <artifactId>standard</artifactId>
        <version>1.1.2</version>
    </dependency>

    <!-- Servlet Dependency -->
    <dependency>
         <groupId>javax.servlet</groupId>
         <artifactId>javax.servlet-api</artifactId>
         <version>3.1.0</version>
         <scope>provided</scope>
    </dependency>

    <!-- JSP Dependency -->
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>javax.servlet.jsp-api</artifactId>
        <version>2.3.1</version>
        <scope>provided</scope>
    </dependency>
 </dependencies>

  <build>
<sourceDirectory>src</sourceDirectory>
<plugins>
  <plugin>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.8.0</version>
    <configuration>
      <release>11</release>
    </configuration>
  </plugin>
</plugins>

Answer 1

One of the possible issues is that you package naming is wrong. Folder structure for maven projects looks like that:

src
  |_ main
  |     |_ java
  |     |     |_ your.actual.package
  |     |_ resources
  |     |_ webapp
  |_ test
        |_ java
              |_ your.actual.package

So your actual package starts right after java folder. That means that you actually have:

• config package instead of main.java.config for AppConfig class

• controller package instead of main.java.controller for JavaController

• model package instead of main.java.model for HelloWorld

Also you need to change your @ComponentScan . Leave it empty to scan root package. Or try to use basePackageClasses if that doesn't work.

Afterwards you need to check you war file. Unpack it and check that WEB-INF folder contains .class files for all created classes and views has your helloworld.jsp file.

I hope this will help.

Answer 2

Not sure where is exactly the problem, but here is a complete project for you. You can get help from here:

https://github.com/imrangthub/BlogSolutionUsingSpringHibernateWithClassLevelConfig

Answer 3

1-

You should list all your packages including configuration classes in @ComponentScan annotation instead main.java : @ComponentScan(basePackages = {"config","controller"})

Or

Move all your packages inside a parent package (example : com.project) like com.project.config, com.project.controller, com.project.model and use it:

@ComponentScan(basePackages = {"com.project"})

2- Check the web dependency assembly of your project, it should be like this:

If is your config not like this, you should add it by clicking on Add button and selecting java Build Path Entries.

And select Maven Dependencies in the next window.