Spring boot将配置属性注入到bean类中
following:https://blog.csdn.net/jiaobuchong/article/details/50442709
一、@ConfigurationProperties注解的使用
看配置文件，我的是yaml格式的配置：
// file application.yml
my:
servers:
- dev.bar.com
- foo.bar.com - jiaobuchong.com下面我要将上面的配置属性注入到一个Java Bean类中，看码：
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import java.util.ArrayList;
import java.util.List;
/** * file: MyConfig.java * Created by jiaobuchong on 12/29/15. */ @Component //不加这个注解的话, 使用@Autowired 就不能注入进去了 @ConfigurationProperties(prefix = "my") // 配置文件中的前缀 public class MyConfig { private List<String> servers = new ArrayList<String>(); public List<String> getServers() { return this.servers; } }
下面写一个Controller来测试一下：
/**
* file： HelloController
* Created by jiaobuchong on 2015/12/4.
*/
@RequestMapping("/test")
@RestController
public class HelloController { @Autowired private MyConfig myConfig; @RequestMapping("/config") public Object getConfig() { return myConfig.getServers(); } }下面运行Application.java的main方法跑一下看看：
@Configuration //标注一个类是配置类，spring boot在扫到这个注解时自动加载这个类相关的功能，比如前面的文章中介绍的配置AOP和拦截器时加在类上的Configuration
@EnableAutoConfiguration //启用自动配置 该框架就能够进行行为的配置，以引导应用程序的启动与运行, 根据导入的starter-pom 自动加载配置
@ComponentScan //扫描组件 @ComponentScan(value = "com.spriboot.controller") 配置扫描组件的路径 public class Application { public static void main(String[] args) { // 启动Spring Boot项目的唯一入口 SpringApplication app = new SpringApplication(Application.class); app.setBannerMode(Banner.Mode.OFF); app.run(args); }在浏览器的地址栏里输入：
localhost:8080/test/config 得到：
[“dev.bar.com”,”foo.bar.com”,”jiaobuchong.com”]
二、@ConfigurationProperties和@EnableConfigurationProperties注解结合使用
在spring boot中使用yaml进行配置的一般步骤是，
1、yaml配置文件，这里假设：
my:
webserver:
#HTTP 监听端口
port: 80
#嵌入Web服务器的线程池配置
threadPool:
maxThreads: 100 minThreads: 8 idleTimeout: 600002、
//file MyWebServerConfigurationProperties.java
import org.springframework.boot.context.properties.ConfigurationProperties;
@ConfigurationProperties(prefix = "my.webserver")
public class MyWebServerConfigurationProperties {
private int port; private ThreadPool threadPool; public int getPort() { return port; } public void setPort(int port) { this.port = port; } public ThreadPool getThreadPool() { return threadPool; } public void setThreadPool(ThreadPool threadPool) { this.threadPool = threadPool; } public static class ThreadPool { private int maxThreads; private int minThreads; private int idleTimeout; public int getIdleTimeout() { return idleTimeout; } public void setIdleTimeout(int idleTimeout) { this.idleTimeout = idleTimeout; } public int getMaxThreads() { return maxThreads; } public void setMaxThreads(int maxThreads) { this.maxThreads = maxThreads; } public int getMinThreads() { return minThreads; } public void setMinThreads(int minThreads) { this.minThreads = minThreads; } } }3、
// file: MyWebServerConfiguration.java
import org.springframework.context.annotation.Configuration;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
@Configuration
@EnableConfigurationProperties(MyWebServerConfigurationProperties.class) public class MyWebServerConfiguration { @Autowired private MyWebServerConfigurationProperties properties; /** *下面就可以引用MyWebServerConfigurationProperties类 里的配置了 */ public void setMyconfig() { String port = properties.getPort(); // ........... } }
The @EnableConfigurationProperties annotation is automatically applied to your project so that any beans annotated with @ConfigurationProperties will be configured from the Environment properties. This style of configuration works particularly well with the SpringApplication external YAML configuration.(引自spring boot官方手册)
三、@Bean配置第三方组件(Third-party configuration)
创建一个bean类：
// file ThreadPoolBean.java
/**
* Created by jiaobuchong on 1/4/16.
*/
public class ThreadPoolBean { private int maxThreads; private int minThreads; private int idleTimeout; public int getMaxThreads() { return maxThreads; } public void setMaxThreads(int maxThreads) { this.maxThreads = maxThreads; } public int getMinThreads() { return minThreads; } public void setMinThreads(int minThreads) { this.minThreads = minThreads; } public int getIdleTimeout() { return idleTimeout; } public void setIdleTimeout(int idleTimeout) { this.idleTimeout = idleTimeout; } }引用前面第二部分写的配置类：MyWebServerConfiguration.java和MyWebServerConfigurationProperties.java以及yaml配置文件,现在修改MyWebServerConfiguration.java类：
import com.jiaobuchong.springboot.domain.ThreadPoolBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration; /** * Created by jiaobuchong on 1/4/16. */ @Configuration //这是一个配置类，与@Service、@Component的效果类似。spring会扫描到这个类，@Bean才会生效，将ThreadPoolBean这个返回值类注册到spring上下文环境中 @EnableConfigurationProperties(MyWebServerConfigurationProperties.class) //通过这个注解, 将MyWebServerConfigurationProperties这个类的配置到上下文环境中,本类中使用的@Autowired注解注入才能生效 public class MyWebServerConfiguration { @SuppressWarnings("SpringJavaAutowiringInspection") //加这个注解让IDE 不报: Could not autowire @Autowired private MyWebServerConfigurationProperties properties; @Bean //@Bean注解在方法上,返回值是一个类的实例,并声明这个返回值(返回一个对象)是spring上下文环境中的一个bean public ThreadPoolBean getThreadBean() { MyWebServerConfigurationProperties.ThreadPool threadPool = properties.getThreadPool(); ThreadPoolBean threadPoolBean = new ThreadPoolBean(); threadPoolBean.setIdleTimeout(threadPool.getIdleTimeout()); threadPoolBean.setMaxThreads(threadPool.getMaxThreads()); threadPoolBean.setMinThreads(threadPool.getMinThreads()); return threadPoolBean; } }被@Configuration注解标识的类，通常作为一个配置类，这就类似于一个xml文件，表示在该类中将配置Bean元数据，其作用类似于Spring里面application-context.xml的配置文件，而@Bean标签，则类似于该xml文件中，声明的一个bean实例。
写一个controller测试一下：
import com.jiaobuchong.springboot.domain.ThreadPoolBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/** * Created by jiaobuchong on 2015/12/4. */ @RequestMapping("/first") @RestController public class HelloController { @Autowired private ThreadPoolBean threadPoolBean; @RequestMapping("/testbean") public Object getThreadBean() { return threadPoolBean; } }
运行Application.java的main方法，
在浏览器里输入：http://localhost:8080/first/testbean
得到的返回值是：
{“maxThreads”:100,”minThreads”:8,”idleTimeout”:60000}