一、简介
springboot 最强大的功能就是把我们常用的场景抽取成了一个个starter（场景启动器），我们通过引入springboot 为我提供的这些场景启动器，我们再进行少量的配置就能使用相应的功能。即使是这样，springboot也不能囊括我们所有的使用场景，往往我们需要自定义starter，来简化我们对springboot的使用。
下面话不多说了，来一起看看详细的介绍吧
二、如何自定义starter
1.实例
如何编写自动配置 ？
我们参照@webmvcautoconfiguration为例，我们看看需要准备哪些东西，下面是webmvcautoconfiguration的部分代码：
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@configuration@conditionalonwebapplication@conditionalonclass({servlet.class, dispatcherservlet.class, webmvcconfigureradapter.class})@conditionalonmissingbean({webmvcconfigurationsupport.class})@autoconfigureorder(-2147483638)@autoconfigureafter({dispatcherservletautoconfiguration.class, validationautoconfiguration.class})public class webmvcautoconfiguration { @import({webmvcautoconfiguration.enablewebmvcconfiguration.class}) @enableconfigurationproperties({webmvcproperties.class, resourceproperties.class}) public static class webmvcautoconfigurationadapter extends webmvcconfigureradapter { @bean @conditionalonbean({view.class}) @conditionalonmissingbean public beannameviewresolver beannameviewresolver() { beannameviewresolver resolver = new beannameviewresolver(); resolver.setorder(2147483637); return resolver; } }} |
我们可以抽取到我们自定义starter时,同样需要的一些配置。
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@configuration //指定这个类是一个配置类@conditionalonxxx //指定条件成立的情况下自动配置类生效@autoconfigureorder //指定自动配置类的顺序@bean //向容器中添加组件@configurationproperties //结合相关xxxproperties来绑定相关的配置@enableconfigurationproperties //让xxxproperties生效加入到容器中自动配置类要能加载需要将自动配置类，配置在meta-inf/spring.factories中org.springframework.boot.autoconfigure.enableautoconfiguration=\org.springframework.boot.autoconfigure.admin.springapplicationadminjmxautoconfiguration,\org.springframework.boot.autoconfigure.aop.aopautoconfiguration,\ |
模式
我们参照 spring-boot-starter 我们发现其中没有代码：
我们在看它的pom中的依赖中有个 springboot-starter
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<dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter</artifactid></dependency> |
我们再看看 spring-boot-starter 有个 spring-boot-autoconfigure
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<dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-autoconfigure</artifactid></dependency> |
关于web的一些自动配置都写在了这里 ，所以我们有以下总结：
启动器starter只是用来做依赖管理
需要专门写一个类似spring-boot-autoconfigure的配置模块
用的时候只需要引入启动器starter，就可以使用自动配置了
命名规范
官方命名空间
- 前缀：spring-boot-starter-
- 模式：spring-boot-starter-模块名
- 举例：spring-boot-starter-web、spring-boot-starter-jdbc
自定义命名空间
- 后缀：-spring-boot-starter
- 模式：模块-spring-boot-starter
- 举例：mybatis-spring-boot-starter
三、自定义starter实例
我们需要先创建两个工程 hello-spring-boot-starter 和 hello-spring-boot-starter-autoconfigurer
1. hello-spring-boot-starter
1.pom.xml
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<?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.gf</groupid> <artifactid>hello-spring-boot-starter</artifactid> <version>0.0.1-snapshot</version> <packaging>jar</packaging> <name>hello-spring-boot-starter</name> <!-- 启动器 --> <dependencies> <!-- 引入自动配置模块 --> <dependency> <groupid>com.gf</groupid> <artifactid>hello-spring-boot-starter-autoconfigurer</artifactid> <version>0.0.1-snapshot</version> </dependency> </dependencies></project> |
同时删除 启动类、resources下的文件，test文件。
2. hello-spring-boot-starter-autoconfigurer
1. pom.xml
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<?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.gf</groupid> <artifactid>hello-spring-boot-starter-autoconfigurer</artifactid> <version>0.0.1-snapshot</version> <packaging>jar</packaging> <name>hello-spring-boot-starter-autoconfigurer</name> <description>demo project for spring boot</description> <parent> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-parent</artifactid> <version>1.5.9.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> <!-- 引入spring-boot-starter，所有starter的基本配合 --> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter</artifactid> </dependency> </dependencies></project> |
2. helloproperties
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package com.gf.service;import org.springframework.boot.context.properties.configurationproperties;@configurationproperties(prefix = "gf.hello")public class helloproperties { private string prefix; private string suffix; public string getprefix() { return prefix; } public void setprefix(string prefix) { this.prefix = prefix; } public string getsuffix() { return suffix; } public void setsuffix(string suffix) { this.suffix = suffix; }} |
3. helloservice
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package com.gf.service;public class helloservice { helloproperties helloproperties; public helloproperties gethelloproperties() { return helloproperties; } public void sethelloproperties(helloproperties helloproperties) { this.helloproperties = helloproperties; } public string sayhello(string name ) { return helloproperties.getprefix()+ "-" + name + helloproperties.getsuffix(); }} |
4. helloserviceautoconfiguration
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package com.gf.service;import org.springframework.beans.factory.annotation.autowired;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@conditionalonwebapplication //web应该生效@enableconfigurationproperties(helloproperties.class)public class helloserviceautoconfiguration { @autowired helloproperties helloproperties; @bean public helloservice helloservice() { helloservice service = new helloservice(); service.sethelloproperties( helloproperties ); return service; }} |
5. spring.factories
在 resources 下创建文件夹 meta-inf 并在 meta-inf 下创建文件 spring.factories ，内容如下：
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# auto configureorg.springframework.boot.autoconfigure.enableautoconfiguration=\com.gf.service.helloserviceautoconfiguration |
到这儿，我们的配置自定义的starter就写完了 ，我们把 hello-spring-boot-starter-autoconfigurer、hello-spring-boot-starter 安装成本地jar包。
三、测试自定义starter
我们创建个项目 hello-spring-boot-starter-test，来测试系我们写的stater。
1. pom.xml
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<?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.gf</groupid> <artifactid>hello-spring-boot-starter-test</artifactid> <version>0.0.1-snapshot</version> <packaging>jar</packaging> <name>hello-spring-boot-starter-test</name> <description>demo project for spring boot</description> <parent> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-parent</artifactid> <version>1.5.9.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> <!-- 引入自定义starter --> <dependency> <groupid>com.gf</groupid> <artifactid>hello-spring-boot-starter</artifactid> <version>0.0.1-snapshot</version> </dependency> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-test</artifactid> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-maven-plugin</artifactid> </plugin> </plugins> </build></project> |
2. hellocontroller
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package com.gf.controller;import com.gf.service.helloservice;import org.springframework.beans.factory.annotation.autowired;import org.springframework.web.bind.annotation.getmapping;import org.springframework.web.bind.annotation.pathvariable;import org.springframework.web.bind.annotation.restcontroller;@restcontrollerpublic class hellocontroller { @autowired helloservice helloservice; @getmapping("/hello/{name}") public string hello(@pathvariable(value = "name") string name) { return helloservice.sayhello( name + " , " ); }} |
3. application.properties
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gf.hello.prefix = higf.hello.suffix = what's up man ? |
我运行项目访问 http://127.0.0.1:8080/hello/zhangsan，结果如下：
hi-zhangsan , what's up man ?
源码下载: https://github.com/gf-huanchupk/springbootlearning
总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，谢谢大家对服务器之家的支持。
原文链接：https://juejin.im/post/5c81dda6e51d4539ab383e3a
