Simple Spring Boot Hello World Example Using JSP

Question

Got a problem testing Spring Boot app. Whatever I try to do it's not working for some reason. Thought about an issue with embedded Tomcat and JSP compiling problem, even added another compiler. Yet not working.

Probably the error is somewhere on the surface.

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>

<name>demo</name>
<description>Demo project for Spring Boot</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.3.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-
8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <scope>provided</scope>
    </dependency>

    <dependency>
        <groupId>org.eclipse.jdt.core.compiler</groupId>
        <artifactId>ecj</artifactId>
        <version>4.6.1</version>
        <scope>provided</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>


</project>

SpringServletInitializer

@SpringBootApplication
public class DemoApplication extends SpringBootServletInitializer {

@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
    return application.sources(DemoApplication.class);
}

public static void main(String[] args) throws Exception {
    SpringApplication.run(DemoApplication.class, args);
}
}

And Controller

@Controller
public class BootController {
private String message = "Hello World!";

@RequestMapping("/")
public String welcome(ModelMap model) {
    model.put("message", this.message);
    return "index";
}
}

application.properties

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

Accessing localhost shows whitelabel error page.

project structure

UPDATE

---

When I'm trying to repackage project using mvn spring-boot:repackage I get the following error log:

[INFO] BUILD FAILURE
[INFO] ---------------------------------------------------------------------
---
[INFO] Total time: 5.172 s
[INFO] Finished at: 2017-05-16T14:34:36+06:00
[INFO] Final Memory: 16M/153M
[INFO] ---------------------------------------------------------------------
---
 [ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-
plugin:1.5.3.RELEASE:repackage (default-cli) on project demo: Execution 
default-cli of goal org.springframework.boot:spring-boot-maven-
plugin:1.5.3.RELEASE:repackage failed: Source must refer to an existing file 
-> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e 
switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please 
read the following articles:
[ERROR] [Help 1] 
http://cwiki.apache.org/confluence/display/MAVEN/PluginExecutionException

Still thinking what it can be. I expect this to be some repackaging problem, i can't really track simply because can't make any changes in the project. However, if I create @RestController and just return string, it works fine.

Answer 1

If you are running in embedded tomcat try these deps:

    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
    </dependency>

Answer 2

Try like this:

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {
   public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}