springboot starter自定义实现公共模块方式_Java

springboot中的starter是一种非常重要的机制，能够抛弃以前繁杂的配置，将其统一集成进starter，应用者只需要在maven中引入starter依赖，springboot就能自动扫描到要加载的信息并启动相应的默认配置。

我们将可独立于业务代码之外的功配置模块封装成一个个starter，复用的时候只需要将其在pom中引用依赖即可，springboot为我们完成自动装配。

比如登录模块，基于aop的日志模块等。

springboot提供的starter以spring-boot-starter-xxx的方式命名的。官方建议自定义的starter使用xxx-spring-boot-starter命名规则。以区分springboot生态提供的starter。

以下是定义一个starter的步骤：

1. 建立一个父项目

<?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>

    <parent>
        <groupid>org.springframework.boot</groupid>
        <artifactid>spring-boot-starter-parent</artifactid>
        <version>2.3.9.release</version>
    </parent>

    <groupid>org.example</groupid>
    <artifactid>springboot-starter-demo</artifactid>
    <version>1.0-snapshot</version>
    <modules>
        <module>springboot-starter-config</module>
        <module>springboot-starter-application</module>
    </modules>

    <packaging>pom</packaging>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

</project>

2. 新建一个maven module项目作为自定义starter项目

pom.xml如下：

<?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">

    <parent>
        <artifactid>springboot-starter-demo</artifactid>
        <groupid>org.example</groupid>
        <version>1.0-snapshot</version>
    </parent>
    <modelversion>4.0.0</modelversion>

    <artifactid>springboot-starter-config</artifactid>
    <version>1.0-snapshot</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>

        <dependency>
            <groupid>org.springframework.boot</groupid>
            <artifactid>spring-boot-configuration-processor</artifactid>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupid>org.springframework.boot</groupid>
            <artifactid>spring-boot-starter</artifactid>
        </dependency>
    </dependencies>

</project>

3. 定义属性类

package com.demo;

import org.springframework.boot.context.properties.configurationproperties;

/**
 * 描述：配置信息 实体
 *
 **/
@configurationproperties(prefix = "demo")
public class demoproperties {
    private string params1;
    private string params2;
    private integer minlength;


    public string getparams1() {
        return params1;
    }

    public void setparams1(string params1) {
        this.params1 = params1;
    }

    public string getparams2() {
        return params2;
    }

    public void setparams2(string params2) {
        this.params2 = params2;
    }

    public integer getminlength() {
        return minlength;
    }

    public void setminlength(integer minlength) {
        this.minlength = minlength;
    }
}

4. 定义服务类

package com.demo.service;

import com.demo.demoproperties;
import org.springframework.beans.factory.annotation.autowired;

/**
 * author:huawei
 */
public class demoservice {

    @autowired
    private demoproperties demoproperties;

    public string params1;
    public string params2;

    public demoservice(string param1, string param2) {
        this.params1 = param1;
        this.params2 = param2;
    }

    public string paramsinfo() {
        return this.params1 + "!  " + params2;
    }

    public boolean isvalidlength(string param) {

        int length = param.length();
        integer minlength = demoproperties.getminlength();

        if (length < minlength.intvalue()) {
            return false;
        } else {
            return true;
        }

    }
}

5. 定义配置类

package com.demo;

import com.demo.service.demoservice;
import org.springframework.beans.factory.annotation.autowired;
import org.springframework.boot.autoconfigure.condition.conditionalonproperty;
import org.springframework.boot.context.properties.enableconfigurationproperties;
import org.springframework.context.annotation.bean;
import org.springframework.context.annotation.configuration;

/**
 * 描述：配置类
 *
 **/
@configuration
@enableconfigurationproperties(demoproperties.class)
@conditionalonproperty(
        prefix = "demo",
        name = "enable",
        havingvalue = "true"
)
public class demostarterautoconfig {
    @autowired
    private demoproperties demoproperties;

    @bean(name = "demo")
    public demoservice demoservice(){
        return new demoservice(demoproperties.getparams1(), demoproperties.getparams2());
    }
}

6. 重要的一步

resource目录下添加meta-inf目录，在其下面建立文件spring.factories，内容如下：

org.springframework.boot.autoconfigure.enableautoconfiguration=com.demo.demostarterautoconfig

经过以上步骤，starter就完成了。

以下是建立测试项目的步骤。

7. 建立maven module测试项目

<?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">
    <parent>
        <artifactid>springboot-starter-demo</artifactid>
        <groupid>org.example</groupid>
        <version>1.0-snapshot</version>
    </parent>
    <modelversion>4.0.0</modelversion>

    <artifactid>springboot-starter-application</artifactid>
    <version>1.0-snapshot</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupid>org.springframework.boot</groupid>
            <artifactid>spring-boot-starter-web</artifactid>
        </dependency>

        <dependency>
            <groupid>org.example</groupid>
            <artifactid>springboot-starter-config</artifactid>
            <version>1.0-snapshot</version>
        </dependency>
    </dependencies>

</project>

8. 添加配置文件application.yml

server:
  port: 8010


demo:
  enable: true
  params1: 参数1
  params2: 参数2
  minlength: 4

9. 添加测试controller

package com.demo.starter.controller;

import com.demo.service.demoservice;
import org.springframework.web.bind.annotation.getmapping;
import org.springframework.web.bind.annotation.restcontroller;

import javax.annotation.resource;


@restcontroller
public class appcontroller {

    @resource(name = "demo")
    private demoservice demoservice;

    @getmapping("/test")
    public string test(){

        boolean valid = demoservice.isvalidlength("test");
        if(valid)
            return demoservice.paramsinfo();
        else
            return "无效数据";
    }
}