Springboot (1) Environment construction and demo under idea

1.Spring Boot Introduction

The introduction on the wiki:

Spring Boot is a general configuration solution for spring that creates a standalone, production-level, spring-based application that can "run". ^{It pre-configures spring's "insight view" of the best configuration and use of spring platforms and third-party libraries, so you can start as little as possible. Most spring boot applications require only a small spring configuration. Features:}

• Create a standalone spring application
• directly embed Tomcat or Jetty(no need to deploy WAR file)
• provide a self-righteous "beginner" Project object Model (POM) to simplify your MAVEN configuration
• Automatically configure spring as much as possible
• provides production-ready features such as metrics , health checks, and external configurations
• Absolutely no code generation, no XML configuration required

2. Create a project

Create a new MAVEN project: Open idea and select File->new->project as shown:

Locate the MAVEN project as shown in:

Then, fill in the items,

3.pom.xml Configuration

Refer to the Spring website example: https://spring.io/guides/gs/maven/#initial

As follows:

<?XML version= "1.0" encoding= "UTF-8"?><Projectxmlns= "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>Org.springframework</groupId>    <Artifactid>Myspringboot</Artifactid>    <Packaging>Jar</Packaging>    <version>0.1.0</version>    <Properties>        <Maven.compiler.source>1.8</Maven.compiler.source>        <Maven.compiler.target>1.8</Maven.compiler.target>    </Properties>    <Build>        <Plugins>            <plugin>                <groupId>Org.apache.maven.plugins</groupId>                <Artifactid>Maven-shade-plugin</Artifactid>                <version>2.1</version>                <executions>                    <Execution>                        <Phase>Package</Phase>                        <Goals>                            <goal>Shade</goal>                        </Goals>                        <Configuration>                            <Transformers>                                <TransformerImplementation= "Org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">                                    <MainClass>Com.demo.HelloWorld</MainClass>                                </Transformer>                            </Transformers>                        </Configuration>                    </Execution>                </executions>            </plugin>        </Plugins>    </Build></Project>

In addition to optional <packaging> elements, this is the simplest pom.xml file that is necessary to build a Java project. It includes the following details about the project configuration:

• <modelVersion>。 Pom model version (always 4.0.0).

• <groupId>。 The group or organization to which the project belongs. Typically expressed as a reverse domain name.

• <artifactId>。 The name of the project library artifact to give (for example, the name of its jar or war file).

• <version>。 The version of the project being built.

• <packaging>-How to package the project. For JAR file packaging, the default is "jar". Use "war" to package the war file.

4. Adding a startup class

To create a package under the Src/main/java path, I named Com.demo. Under the package, create a new Java class named HelloWorld as the startup class.

Helloworld.java Code:

 Package Com.demo; Import org.springframework.boot.SpringApplication; Import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication  Public class HelloWorld {    publicstaticvoidthrows  exception{        Springapplication.run (HelloWorld. class , args);}    }

The @springbootapplication used here needs to be added to the pom.xml in the <project> :

<Dependencies>        <!--Https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -        <Dependency>            <groupId>Org.springframework.boot</groupId>            <Artifactid>Spring-boot-starter-web</Artifactid>            <version>1.5.9.RELEASE</version>        </Dependency>
</Dependencies>

Once added, click on the lower right corner of import changes to download the installation automatically.

5. Writing the business layer

Under the Com.demo path, create a package named Controller, under package to create a Java class named Hellocontroller.

This class is primarily used to interact with pages.

Hellocontroller.java Code:

 Package Com.demo.Controller; Import Org.springframework.stereotype.Controller; Import org.springframework.web.bind.annotation.RequestMapping; Import org.springframework.web.bind.annotation.ResponseBody; @Controller  Public class Hellocontroller {    @RequestMapping ("/hello")    @ResponseBody    public  String Hello () {        return "Hello Spring Boot";    }}

6. Running

Such a simple demo is done. You can start the project by running the main method directly in the startup class, because sping boot has built-in Tomcat

You can see that Tomcat is running on port 8080, and in the browser address bar, enter: Http://localhost:8080/hello, which appears:

At this end, the project runs successfully.

7. Questions

• WARNING ** : Your ApplicationContext is unlikely to start due to a @ComponentScan of the default package.

   is due to the startup class file, which is placed directly under the Main/java folder.

Ref: 1190000004493460

is caused by a structural problem with the directory

Ref: 53670112

8. Summary

Just contact spring Boot to write a demo to encounter a lot of problems, spring boot as a new technology, may be used later, it seems to continue to learn.

Springboot (1) Environment construction and demo under idea