SpringBoot autoassembler writes a Starter

When working with the springBoot project, we often use various JARS named ***-starter

For example, mybatis-spring-boot-starter, shiro-spring-boot-web-starter and so on.

When we use these services, we marvel at their magic, just a few lines of configuration can enjoy all kinds of convenience, so how to write this service?

Today we build one from scratch, to see how it works

One: Project initialization

1: First we will create a basic Springboot project called my-starter

<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> The < version > 2.1.6. RELEASE < / version > < relativePath / > <! -- lookup parent from repository --></parent>Copy the code

<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> < version > 2.1.6. RELEASE < / version > <type>pom</type>    <scope>import</scope></dependency>Copy the code

<? 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 > org. The demo < / groupId > < artifactId > my - starter < / artifactId > <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>my-starter</name> <description>Demo projectforSpring Boot</description> <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> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> < version > 2.1.6. RELEASE < / version > <type>pom</type>                <scope>import</scope>            </dependency>        </dependencies>    </dependencyManagement>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>        </plugins>    </build></project>Copy the code

3: Add dependencies

<dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-autoconfigure</artifactId></dependency>Copy the code

Two: Add Properties configuration

package org.demo.mystarter;

import org.springframework.boot.context.properties.ConfigurationProperties;

@ConfigurationProperties(prefix = "my-starter")
public class MyStarterProperties {

    private String name = "chuchen";
    private String projectName = "my-starter";
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getProjectName() {
        return projectName;
    }
    public void setProjectName(String projectName) { this.projectName = projectName; }}Copy the code

my-starter.name=***
my-starter.project-name=***Copy the code

Three: Create a business class

package org.demo.mystarter;

public class MyStarterService {

    private String name;

    private String projectName;

    public String getMyStarterMsg() {return "author is " + name + ",project_name is " + projectName;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getProjectName() {
        return projectName;
    }

    public void setProjectName(String projectName) { this.projectName = projectName; }}Copy the code

Four: automatic assembly

package org.demo.mystarter;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableConfigurationProperties(MyStarterProperties.class)
@ConditionalOnClass(MyStarterService.class)
public class MyStarterAutoConfiguration {

    @Autowired
    private MyStarterProperties myStarterProperties;

    @Bean
    @ConditionalOnMissingBean(MyStarterService.class)
    MyStarterService myStarterService() {
        MyStarterService myStarterService = new MyStarterService();
        myStarterService.setName(myStarterProperties.getName());
        myStarterService.setProjectName(myStarterProperties.getProjectName());
        returnmyStarterService; }}Copy the code

Five: Configuration file

org.springframework.boot.autoconfigure.EnableAutoConfiguration=
org.demo.mystarter.MyStarterAutoConfigurationCopy the code

Six: Jar into the local Maven repository

If the following figure is displayed, the port is added successfully

Seven: testing

<dependency> <groupId>org.demo</groupId> <artifactId>my-starter</artifactId> < version > 0.0.1 - the SNAPSHOT < / version > < / dependency >Copy the code

package com.chuchen.teststarter;

import org.demo.mystarter.MyStarterService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestContrsoller {

    @Autowired
    private MyStarterService myStarterService;

    @GetMapping("/test")
    public String test() {returnmyStarterService.getMyStarterMsg(); }}Copy the code

my-starter.name=beany
my-starter.project-name=testStarterCopy the code

Eight: the last

My series on SpringBoot:

SpringBoot series tutorials