手寫一個Spring Boot Starter

時間 2021-06-30

標籤 java 程序員 redis spring 後端微信 app spring-boot this spa 欄目 Spring 简体版

原文原文鏈接

嗨~你們好，我是阿壯，一個後端程序員，今天和你們分享Spring Boot的自動裝配原理，並手寫一個Starter加深對Spring Boot的理解。java

衆所周知，Spring Boot爲了簡化開發，省去了Spring中不少的XML文件。爲了理解Spring Boot中自動裝配的原理，今天咱們基於這個機制本身動手實現一個Starter組件。程序員

項目結構

步驟

新建一個名爲：redis-spring-boot-starter的Maven項目

添加Maven依賴redis

<dependencies>
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter</artifactId>
     </dependency>
     <dependency>
         <groupId>org.redisson</groupId>
         <artifactId>redisson</artifactId>
         <version>3.11.1</version>
     </dependency>
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-configuration-processor</artifactId>
         <optional>true</optional>
     </dependency>
 </dependencies>
 <dependencyManagement>
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-dependencies</artifactId>
             <version>2.3.2.RELEASE</version>
             <type>pom</type>
             <scope>import</scope>
         </dependency>
     </dependencies>
 </dependencyManagement>

定義屬性，實如今applications.properties中的Redis的鏈接參數。spring

@ConfigurationProperties(prefix = "gp.redisson")
public class RedissonProperties {
 private String host = "localhost";
 private String password;
 private int port = 6379;
 private int timeout;
 private boolean ssl;

 public String getHost() {
     return host;
 }

 public void setHost(String host) {
     this.host = host;
 }

 public String getPassword() {
     return password;
 }

 public void setPassword(String password) {
     this.password = password;
 }

 public int getPort() {
     return port;
 }

 public void setPort(int port) {
     this.port = port;
 }

 public int getTimeout() {
     return timeout;
 }

 public void setTimeout(int timeout) {
     this.timeout = timeout;
 }

 public boolean isSsl() {
     return ssl;
 }

 public void setSsl(boolean ssl) {
     this.ssl = ssl;
 }
}

定義須要自動裝配的配置類後端

@Configuration
@ConditionalOnClass(Redisson.class)
@EnableConfigurationProperties(RedissonProperties.class)
public class RedissonAutoConfiguration {
 @Bean
 RedissonClient redissonClient(RedissonProperties redissonProperties) {
     Config config = new Config();
     String prefix = "redis://";
     if (redissonProperties.isSsl()) {
         prefix = "rediss://";
     }
     SingleServerConfig singleServerConfig = config.useSingleServer()
             .setAddress(prefix + redissonProperties.getHost() + ":" + redissonProperties.getPort())
             .setConnectTimeout(redissonProperties.getTimeout());
     if (!StringUtils.hasText(redissonProperties.getPassword())) {
         singleServerConfig.setPassword(redissonProperties.getPassword());
     }
     return Redisson.create(config);
 }
}

在resource文件夾下新建META-INF/spring.fatories文件，使Spring Boot程序能夠掃描文件完成自動裝配微信
```
org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.jonssonyan.config.RedissonAutoConfiguration
```
打包成jar包

在其餘項目引入當先依賴app

<dependency>
         <groupId>com.jonssonyan</groupId>
         <artifactId>redis-spring-boot-starter</artifactId>
         <version>1.0-SNAPSHOT</version>
     </dependency>