Spring boot將配置屬性注入到bean類中

更新時(shí)間：2017年03月02日 11:13:17 作者：heikeyuit

本篇文章主要介紹了Spring boot將配置屬性注入到bean類中，小編覺(jué)得挺不錯(cuò)的，現(xiàn)在分享給大家，也給大家做個(gè)參考。一起跟隨小編過(guò)來(lái)看看吧

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

下面我要將上面的配置屬性注入到一個(gè)Java Bean類中，看碼：

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   //不加這個(gè)注解的話, 使用@Autowired 就不能注入進(jìn)去了
@ConfigurationProperties(prefix = "my") // 配置文件中的前綴
public class MyConfig {
  private List<String> servers = new ArrayList<String>();
  public List<String> getServers() { return this.servers;
  }
}

下面寫一個(gè)Controller來(lái)測(cè)試一下：

/**
 * 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();
  }
}

下面運(yùn)行Application.java的main方法跑一下看看：

@Configuration  //標(biāo)注一個(gè)類是配置類，spring boot在掃到這個(gè)注解時(shí)自動(dòng)加載這個(gè)類相關(guān)的功能，比如前面的文章中介紹的配置AOP和攔截器時(shí)加在類上的Configuration


@EnableAutoConfiguration //啟用自動(dòng)配置 該框架就能夠進(jìn)行行為的配置，以引導(dǎo)應(yīng)用程序的啟動(dòng)與運(yùn)行, 根據(jù)導(dǎo)入的starter-pom 自動(dòng)加載配置
@ComponentScan //掃描組件 @ComponentScan(value = "com.spriboot.controller") 配置掃描組件的路徑
public class Application {
  public static void main(String[] args) {
    // 啟動(dòng)Spring Boot項(xiàng)目的唯一入口
    SpringApplication app = new SpringApplication(Application.class);
    app.setBannerMode(Banner.Mode.OFF);
    app.run(args);
  }

在瀏覽器的地址欄里輸入：

localhost:8080/test/config 得到：

[“dev.bar.com”,”foo.bar.com”,”jiaobuchong.com”]

二、@ConfigurationProperties和@EnableConfigurationProperties注解結(jié)合使用

在spring boot中使用yaml進(jìn)行配置的一般步驟是，

1、yaml配置文件，這里假設(shè)：

my:
 webserver:
  #HTTP 監(jiān)聽端口
  port: 80
  #嵌入Web服務(wù)器的線程池配置
  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類    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官方手冊(cè))

三、@Bean配置第三方組件(Third-party configuration)

創(chuàng)建一個(gè)bean類：

// 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;
  }
}

引用前面第二部分寫的配置類：MyWebServerConfiguration.java和MyWebServerConfigurationProperties.java以及yaml配置文件,現(xiàn)在修改MyWebServerConfiguration.java類：

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 //這是一個(gè)配置類，與@Service、@Component的效果類似。spring會(huì)掃描到這個(gè)類，@Bean才會(huì)生效，將ThreadPoolBean這個(gè)返回值類注冊(cè)到spring上下文環(huán)境中
@EnableConfigurationProperties(MyWebServerConfigurationProperties.class) //通過(guò)這個(gè)注解, 將MyWebServerConfigurationProperties這個(gè)類的配置到上下文環(huán)境中,本類中使用的@Autowired注解注入才能生效
public class MyWebServerConfiguration {
  @SuppressWarnings("SpringJavaAutowiringInspection") //加這個(gè)注解讓IDE 不報(bào): Could not autowire
  @Autowired
  private MyWebServerConfigurationProperties properties;

  @Bean //@Bean注解在方法上,返回值是一個(gè)類的實(shí)例,并聲明這個(gè)返回值(返回一個(gè)對(duì)象)是spring上下文環(huán)境中的一個(gè)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注解標(biāo)識(shí)的類，通常作為一個(gè)配置類，這就類似于一個(gè)xml文件，表示在該類中將配置Bean元數(shù)據(jù)，其作用類似于Spring里面application-context.xml的配置文件，而@Bean標(biāo)簽，則類似于該xml文件中，聲明的一個(gè)bean實(shí)例。
寫一個(gè)controller測(cè)試一下：

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;
  }

}

運(yùn)行Application.java的main方法，

在瀏覽器里輸入：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?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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