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：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
@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。
|
1
2
3
4
5
6
7
8
9
10
11
|
@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
|
1
2
3
4
|
<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
|
1
2
3
4
|
<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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
<?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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
<?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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
|
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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
|
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：
|
1
2
3
|
# auto configure
org.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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
<?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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
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;
@restcontroller
public class hellocontroller {
@autowired
helloservice helloservice;
@getmapping("/hello/{name}")
public string hello(@pathvariable(value = "name") string name) {
return helloservice.sayhello( name + " , " );
}
}
|
3. application.properties
|
1
2
|
gf.hello.prefix = hi
gf.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