springboot 个人感觉特点:
1)众多库的集合(各种starter),方便快速构建应用系统。
2)自动配置spring(通过autoconfiguration机制),简化配置,也方便扩展新的starter。
3)内嵌web容器,无需war部署。
创建一个用maven构建的springboot项目
pom文件配置如下:
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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.xjw.springboot</groupid>
<artifactid>hellostarter</artifactid>
<version> 0.0 . 1 -snapshot</version>
<packaging>jar</packaging>
<name>hello-spring-boot-starter</name>
<description>测试自定义starter</description>
<parent>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-starter-parent</artifactid>
<version> 1.5 . 2 .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</artifactid>
</dependency>
<dependency>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-starter-test</artifactid>
<scope>test</scope>
</dependency>
<dependency>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-configuration-processor</artifactid>
<optional> true </optional>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-maven-plugin</artifactid>
</plugin>
</plugins>
</build>
</project>
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定义一个pojo用来接收properties中配置的信息
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package com.xjw;
import org.springframework.boot.context.properties.configurationproperties;
@configurationproperties (prefix = "hello" )
public class helloserviceproperteis {
private string msg;
public string getmsg() {
return msg;
}
public void setmsg(string msg) {
this .msg = msg;
}
}
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@configurationproperties:用来标识这个pojo是一个用来接收指定前缀的资源配置值
prefix:表示在配置文件中配置项前缀[/code]
编写一个service用来对外提供服务
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package com.xjw;
public class helloservice {
private string msg;
public string sayhello() {
return "hello " + msg;
}
public string getmsg() {
return msg;
}
public void setmsg(string msg) {
this .msg = msg;
}
}
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配置一个pojo用来读取上面配置的helloserviceproperteis
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package com.xjw;
import org.springframework.beans.factory.annotation.autowired;
import org.springframework.boot.autoconfigure.condition.conditionalonclass;
import org.springframework.boot.autoconfigure.condition.conditionalonmissingbean;
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;
@configuration @enableconfigurationproperties (value = helloserviceproperteis. class )
@conditionalonclass (helloservice. class )
@conditionalonproperty (prefix = "hello" , value = "enable" , matchifmissing = true )
public class helloautoconfiguration {
@autowired private helloserviceproperteis helloserviceproperteis;
@bean @conditionalonmissingbean (helloservice. class )
public helloservice helloservice() {
helloservice helloservice = new helloservice();
helloservice.setmsg(helloserviceproperteis.getmsg());
return helloservice;
}
}
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@configuration:标识此类为一个spring配置类
@enableconfigurationproperties(value = helloserviceproperteis.class):启动配置文件,value用来指定我们要启用的配置类,可以有多个,多个时我们可以这么写value={xxproperties1.class,xxproperteis2.class....}
@conditionalonclass(helloservice.class):表示当classpath下存在helloservice.class文件时改配置文件类才有效
@conditionalonproperty(prefix = "hello", value = "enable", matchifmissing = true):表示只有我们的配置文件是否配置了以hello为前缀的资源项值,并且在该资源项值为enable,如果没有配置我们默认设置为enable[/code]
最后在src/main/resources 文件夹下新建文件夹 meta-inf,在新建的meta-inf文件夹下新建spring.factories
在新建的spring.factories文件中配置自动启动类为我们之前编写的helloautoconfiguration 类
org.springframework.boot.autoconfigure.enableautoconfiguration=com.xjw.helloautoconfiguration
然后就可以在其他的spring-boot项目中使用我们刚刚新建的starter了,我们来测试一下
在新建一个spring-boot项目,pom.xml配置如下:
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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.xjw.springboot</groupid>
<artifactid>hellostarter.test</artifactid>
<version> 0.0 . 1 -snapshot</version>
<packaging>jar</packaging>
<name>hello-spring-boot-starter-test</name>
<description>测试自定义starter</description>
<parent>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-starter-parent</artifactid>
<version> 1.5 . 2 .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>
<dependency>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-starter-test</artifactid>
<scope>test</scope>
</dependency>
<dependency>
<groupid>com.xjw.springboot</groupid>
<artifactid>hellostarter</artifactid>
<version> 0.0 . 1 -snapshot</version>
</dependency>
<dependency>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-devtools</artifactid>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-maven-plugin</artifactid>
</plugin>
</plugins>
</build>
</project>
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然后我们直接在咋们的启动类中中尝试使用以下我们上面定义的starter提供的helloservice:
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package com.xjw;
import org.springframework.beans.factory.annotation.autowired;
import org.springframework.boot.springapplication;
import org.springframework.boot.autoconfigure.springbootapplication;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.restcontroller;
@restcontroller
@springbootapplication
public class hellospringbootstartertestapplication {
@autowired
private helloservice helloservice;
@requestmapping ( "/" )
public string index() {
return helloservice.sayhello();
}
public static void main(string[] args) {
springapplication.run(hellospringbootstartertestapplication. class , args);
}
}
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接着我们修改测试项目中的application.properteis,加入如下配置:
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debug= true
server.port= 8888
#hello=enable
hello.msg=测试starter
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最后启动项目,观察控制台输出的内容中依赖的starter,从positive matches下我们可以看到有这么一句:
helloautoconfiguration matched:
- @conditionalonclass found required class 'com.xjw.helloservice'; @conditionalonmissingclass did not find unwanted class (onclasscondition)
- @conditionalonproperty (hello.enable) matched (onpropertycondition)
或者我们打开项目依赖树也能找到我们的starter ,这说明spring已经自动的启动了我们的starter了,打开浏览器输入地址:http://localhost:8888/将会看到如下结果
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:https://www.cnblogs.com/cz-xjw/p/6632402.html