Spring boot自动配置类实战
一 新建一个starter pom的Maven项目
1 编写pom.xml文件
4.0.0
com.wisely
spring-boot-starter-hello
0.0.1-SNAPSHOT
jar
spring-boot-starter-hello
http://maven.apache.org
UTF-8
org.springframework.boot
spring-boot-autoconfigure
1.3.7.RELEASE
junit
junit
3.8.1
test
2 属性配置
package com.wisely.spring_boot_starter_hello;
import org.springframework.boot.context.properties.ConfigurationProperties;
@ConfigurationProperties(prefix = "hello")
public class HelloServiceProperties {
private static final String MSG="world";
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
private String msg=MSG;
}3 判断依据类
根据此类的存在与否来创建者个类的Bean。
package com.wisely.spring_boot_starter_hello;
public class HelloService {
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
private String msg;
public String sayHello()
{
return "hello"+msg;
}
}4 自动配置类
package com.wisely.spring_boot_starter_hello;
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(HelloServiceProperties.class)
//判断HelloService这个类在类路径中是否存在
@ConditionalOnClass(HelloService.class)
@ConditionalOnProperty(prefix = "hello",value = "enabled",matchIfMissing = true)
public class HelloServiceAutoConfiguration {
@Autowired
private HelloServiceProperties helloServiceProperties;
@Bean
@ConditionalOnMissingBean(HelloService.class)
public HelloService helloService()
{
HelloService helloService=new HelloService();
helloService.setMsg(helloServiceProperties.getMsg());
return helloService;
}
}5 在src/main/resource/META-INF的sping。factories中注册配置
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.wisely.spring_boot_starter_hello.HelloServiceAutoConfiguration6 安装
E:\springboot\springbootstarterhello>mvn install
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------< com.wisely:spring-boot-starter-hello >----------------
[INFO] Building spring-boot-starter-hello 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ spring-boot-starter-hello ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ spring-boot-starter-hello ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 3 source files to E:\springboot\springbootstarterhello\target\classes
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ spring-boot-starter-hello ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory E:\springboot\springbootstarterhello\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ spring-boot-starter-hello ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ spring-boot-starter-hello ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ spring-boot-starter-hello ---
[INFO] Building jar: E:\springboot\springbootstarterhello\target\spring-boot-starter-hello-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] --- maven-install-plugin:2.4:install (default-install) @ spring-boot-starter-hello ---
[INFO] Installing E:\springboot\springbootstarterhello\target\spring-boot-starter-hello-0.0.1-SNAPSHOT.jar to D:\.m2\repos\com\wisely\spring-boot-starter-hello\0.0.1-SNAPSHOT\spring-boot-starter-hello-0.
0.1-SNAPSHOT.jar
[INFO] Installing E:\springboot\springbootstarterhello\pom.xml to D:\.m2\repos\com\wisely\spring-boot-starter-hello\0.0.1-SNAPSHOT\spring-boot-starter-hello-0.0.1-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.345 s
[INFO] Finished at: 2018-08-22T19:29:24+08:00
[INFO] ------------------------------------------------------------------------二 使用start pom
1 新建Spring Boot项目，并将我们的starter作为依赖
4.0.0
com.wisely
ch6_5
0.0.1-SNAPSHOT
jar
ch6_5
Demo project for Spring Boot
org.springframework.boot
spring-boot-starter-parent
1.3.7.RELEASE
UTF-8
1.8
org.springframework.boot
spring-boot-starter-web
com.wisely
spring-boot-starter-hello
0.0.1-SNAPSHOT
org.springframework.boot
spring-boot-starter-test
test
org.springframework.boot
spring-boot-maven-plugin
2 查看Maven的依赖
3 编写主类
package com.wisely.ch6_5;
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;
import com.wisely.spring_boot_starter_hello.HelloService;
@RestController
@SpringBootApplication
public class Ch65Application {
//直接注入HelloService的Bean，但是项目中并没有配置这个Bean，这是通过自动化配置完成的。
@Autowired
HelloService helloService;
@RequestMapping("/")
public String index(){
return helloService.sayHello();
}
public static void main(String[] args) {
SpringApplication.run(Ch65Application.class, args);
}
}4 配置文件
hello.msg= :cakin
debug=true5 运行后测试
6 查看自动配置报告
