SpringBoot学习(2) - 自定义starter

自己开发一个spring boot starter的步骤
1.新建一个项目（全部都基于maven），比如新建一个spring-boot-starter-redis的maven项目

pom.xml:

 <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.study.spring-boot</groupId>
     <artifactId>spring-boot-starter-redis</artifactId>
     <version>1.0.0</version>
     <packaging>jar</packaging>

     <name>spring-boot-starter-redis</name>
     <url>http://maven.apache.org</url>

     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>

     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter</artifactId>
             <version>1.5.3.RELEASE</version>
         </dependency>
         <dependency>
             <groupId>redis.clients</groupId>
             <artifactId>jedis</artifactId>
             <version>2.9.0</version>
         </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
             <version>3.8.1</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
 </project>

2.需要一个配置类，配置类里面需要装配好需要提供出去的类

配置类：

 package com.study.spring_boot_redis;

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

 @ConfigurationProperties(prefix="redis")
 public class RedisProperties {
     private String host;
     private Integer port;
     public String getHost() {
         return host;
     }
     public void setHost(String host) {
         this.host = host;
     }
     public Integer getPort() {
         return port;
     }
     public void setPort(Integer port) {
         this.port = port;
     }
 }

 package com.study.spring_boot_redis;

 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;

 import redis.clients.jedis.Jedis;

 @Configuration
 @ConditionalOnClass(Jedis.class)
 @EnableConfigurationProperties(RedisProperties.class)
 public class RedisAutoConfiguration {
     @Bean
     @ConditionalOnMissingBean
     public Jedis Jedis(RedisProperties redisProperties) {
         return new Jedis(redisProperties.getHost(),redisProperties.getPort());

     }
 }

3.
(1)使用@Enable，使用@Import导入需要装配的类

Enable注解：

 package com.study.spring_boot_redis;

 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;

 import org.springframework.context.annotation.Import;

 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 @Import(RedisAutoConfiguration.class)
 public @interface EnableRedis {

 }

(2)/META-INF/spring.factories，在org.springframework.boot.autoconfigure.EnableAutoConfiguration配置需要装配的类

/spring-boot-starter-redis/src/main/resources/META-INF/spring.factories：

 org.springframework.boot.autoconfigure.EnableAutoConfiguration = com.study.spring_boot_redis.RedisAutoConfiguration

真正的项目：springbootstarter（maven项目）

pom.xml:

 <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.study.springboot</groupId>
     <artifactId>springboot</artifactId>
     <version>1.0.0</version>
     <packaging>jar</packaging>

     <name>springboot</name>
     <url>http://maven.apache.org</url>

     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>

     <dependencyManagement>
         <dependencies>
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-dependencies</artifactId>
                 <version>1.5.3.RELEASE</version>
                 <scope>import</scope>
                 <type>pom</type>
             </dependency>
         </dependencies>
     </dependencyManagement>

     <dependencies>
         <dependency>
             <groupId>com.study.spring-boot</groupId>
             <artifactId>spring-boot-starter-redis</artifactId>
             <version>1.0.0</version>
         </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
             <scope>test</scope>
         </dependency>
     </dependencies>
 </project>

/springbootstarter/src/main/resources/application.properties:

 redis.host=127.0.0.1
 redis.port=6379

 //@EnableRedis
 @SpringBootApplication
 public class App {

     public static void main(String[] args) {
         ConfigurableApplicationContext context = SpringApplication.run(App.class,args);
         Jedis jedis = context.getBean(Jedis.class);
         jedis.set("id", "root123");
         System.out.println(jedis.get("id"));
         context.close();
     }

 }