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:

 1 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 2     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 3     <modelVersion>4.0.0</modelVersion>
 4
 5     <groupId>com.study.spring-boot</groupId>
 6     <artifactId>spring-boot-starter-redis</artifactId>
 7     <version>1.0.0</version>
 8     <packaging>jar</packaging>
 9
10     <name>spring-boot-starter-redis</name>
11     <url>http://maven.apache.org</url>
12
13     <properties>
14         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
15     </properties>
16
17     <dependencies>
18         <dependency>
19             <groupId>org.springframework.boot</groupId>
20             <artifactId>spring-boot-starter</artifactId>
21             <version>1.5.3.RELEASE</version>
22         </dependency>
23         <dependency>
24             <groupId>redis.clients</groupId>
25             <artifactId>jedis</artifactId>
26             <version>2.9.0</version>
27         </dependency>
28         <dependency>
29             <groupId>junit</groupId>
30             <artifactId>junit</artifactId>
31             <version>3.8.1</version>
32             <scope>test</scope>
33         </dependency>
34     </dependencies>
35 </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：

 1 package com.study.spring_boot_redis;
 2
 3 import org.springframework.boot.context.properties.ConfigurationProperties;
 4
 5 @ConfigurationProperties(prefix="redis")
 6 public class RedisProperties {
 7     private String host;
 8     private Integer port;
 9     public String getHost() {
10         return host;
11     }
12     public void setHost(String host) {
13         this.host = host;
14     }
15     public Integer getPort() {
16         return port;
17     }
18     public void setPort(Integer port) {
19         this.port = port;
20     }
21 }

 1 package com.study.spring_boot_redis;
 2
 3
 4 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 5 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 6 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 7 import org.springframework.context.annotation.Bean;
 8 import org.springframework.context.annotation.Configuration;
 9
10 import redis.clients.jedis.Jedis;
11
12 @Configuration
13 @ConditionalOnClass(Jedis.class)
14 @EnableConfigurationProperties(RedisProperties.class)
15 public class RedisAutoConfiguration {
16     @Bean
17     @ConditionalOnMissingBean
18     public Jedis Jedis(RedisProperties redisProperties) {
19         return new Jedis(redisProperties.getHost(),redisProperties.getPort());
20
21     }
22 }

3.
(1)使用@Enable，使用@Import导入需要装配的类

Enable注解：

 1 package com.study.spring_boot_redis;
 2
 3 import java.lang.annotation.Documented;
 4 import java.lang.annotation.ElementType;
 5 import java.lang.annotation.Retention;
 6 import java.lang.annotation.RetentionPolicy;
 7 import java.lang.annotation.Target;
 8
 9 import org.springframework.context.annotation.Import;
10
11 @Target(ElementType.TYPE)
12 @Retention(RetentionPolicy.RUNTIME)
13 @Documented
14 @Import(RedisAutoConfiguration.class)
15 public @interface EnableRedis {
16
17 }

(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：

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

真正的项目：springbootstarter（maven项目）

pom.xml:

 1 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 2     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 3     <modelVersion>4.0.0</modelVersion>
 4
 5     <groupId>com.study.springboot</groupId>
 6     <artifactId>springboot</artifactId>
 7     <version>1.0.0</version>
 8     <packaging>jar</packaging>
 9
10     <name>springboot</name>
11     <url>http://maven.apache.org</url>
12
13     <properties>
14         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
15     </properties>
16
17     <dependencyManagement>
18         <dependencies>
19             <dependency>
20                 <groupId>org.springframework.boot</groupId>
21                 <artifactId>spring-boot-dependencies</artifactId>
22                 <version>1.5.3.RELEASE</version>
23                 <scope>import</scope>
24                 <type>pom</type>
25             </dependency>
26         </dependencies>
27     </dependencyManagement>
28
29     <dependencies>
30         <dependency>
31             <groupId>com.study.spring-boot</groupId>
32             <artifactId>spring-boot-starter-redis</artifactId>
33             <version>1.0.0</version>
34         </dependency>
35         <dependency>
36             <groupId>junit</groupId>
37             <artifactId>junit</artifactId>
38             <scope>test</scope>
39         </dependency>
40     </dependencies>
41 </project>

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

1 redis.host=127.0.0.1
2 redis.port=6379

 1 //@EnableRedis
 2 @SpringBootApplication
 3 public class App {
 4
 5     public static void main(String[] args) {
 6         ConfigurableApplicationContext context = SpringApplication.run(App.class,args);
 7         Jedis jedis = context.getBean(Jedis.class);
 8         jedis.set("id", "root123");
 9         System.out.println(jedis.get("id"));
10         context.close();
11     }
12
13 }