Spring boot将配置属性注入到bean类中

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: 60000

2、

//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}

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。