自定義starter的建立
一.自定義啟動器的命名規則
啟動器命名規則:
springboot官方的命名規則是:spring-boot-starter-xxx
自定義的啟動器的命名規則是:xxx-spring-boot-starter
二.構建啟動器的步驟
1.首先建立一個空專案
2.建立兩個子工程
1.點選加號新增一個maven工程,命名為mystarter-spring-boot-starter
2.再點選加號建立一個springboot專案,命名為mystarter-spring-boot-starter-autoconfigurater
讓該maven專案依賴於這個springboot專案
maven專案的pom檔案:
<?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>com.cb.starter</groupId>
<artifactId>mystarter-spring-boot-starter</artifactId>
<version>1.0-SNAPSHOT</version>
<!-- 新增對啟動器自動配置的依賴-->
<dependencies>
<dependency>
<groupId>com.cb.starter</groupId >
<artifactId>mystarter-spring-boot-starter-autoconfigurater</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
</project>
springboot專案的pom.xml:
<?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>com.cb.starter</groupId>
<artifactId>mystarter-spring-boot-starter-autoconfigurater</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>mystarter-spring-boot-starter-autoconfigurater</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<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>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
3.在springboot中編寫配置
1.新建配置檔案類HelloProperties.java
package com.cb.starter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
@ConfigurationProperties(prefix = "hello")
public class HelloProperties {
private String msg ;
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
}
2.建立一個service
package com.cb.starter;
public class HelloService {
HelloProperties helloProperties;
public HelloProperties getHelloProperties() {
return helloProperties;
}
public void setHelloProperties(HelloProperties helloProperties) {
this.helloProperties = helloProperties;
}
public String sayhello(String name){
return "hello "+ name + helloProperties.getMsg();
}
}
3.建立一個配置類
package com.cb.starter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnNotWebApplication;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
@EnableConfigurationProperties(HelloProperties.class) //匯入配置檔案
@ConditionalOnWebApplication //web環境下才起作用
public class HelloConfiguration {
@Autowired
HelloProperties helloProperties;
@Bean //返回給容器一個name=helloService的bean
public HelloService helloService(){
HelloService helloService = new HelloService();
helloService.setHelloProperties(helloProperties);
return helloService;
}
}
4. 配置啟動器的類路徑
springboot自動配置的原理就是在啟動類上加@springbootapplication註解,這個註解包含
@EnableAutoConfiguration,配置類要想在啟動時自動載入,必須要配置在EnableAutoConfiguration下,
這個東西預設是去類路徑下的META-INF下的spring.factories下去找的。我們在resources下新建META-INF資料夾。
之後打成jar包後,就和其他的maven倉庫的jar一樣的結構了。
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.cb.starter.HelloConfiguration
5.點選idea右側的maven project
先對springboot專案進行install,安裝到本地倉庫。在對maven專案進行安裝 ,此時倉庫裡已有這兩個jar包了。
我們可以直接來使用,就像使用基本的jar一樣。
三. 測試啟動器
新建一個springboot專案,pom.xml新增啟動器的id
<!--引入自己配置的starter-->
<dependency>
<groupId>com.cb.starter</groupId>
<artifactId>mystarter-spring-boot-starter</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
此時可以看到,專案的external libraries下已經有了我們剛剛構建的啟動器的jar包了。
新建一個控制器:
package com.cb.starterdemo;
import com.cb.starter.HelloService; //我們自定義的啟動器可以使用
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
@Autowired
HelloService helloService;
@GetMapping(value = "/hello")
public String sayhello(String name){
return helloService.sayhello(name);
}
}
配置檔案中配置一個屬性:
hello.msg = 小蘿莉
顯示:hello 123小蘿莉
ok!大功告成