package com.hannpang.model;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component(value = "st")//對(duì)student進(jìn)行實(shí)例化操作
public class Student {
  @Value("悟空")
  private String name;

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }
}

package com.hannpang.model;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Component;

@Component
public class SimpleObject {

  @Value("注入普通字符串")
  private String normal;

  //關(guān)于屬性的KEY可以查看System類說(shuō)明
  @Value("#{systemProperties['java.version']}")//-->使用了SpEL表達(dá)式
  private String systemPropertiesName; // 注入操作系統(tǒng)屬性

  @Value("#{T(java.lang.Math).random()*80}")//獲取隨機(jī)數(shù)
  private double randomNumber; //注入表達(dá)式結(jié)果

  @Value("#{1+2}")
  private double sum; //注入表達(dá)式結(jié)果 1+2的求和

  @Value("classpath:os.yaml")
  private Resource resourceFile; // 注入文件資源

  @Value("http://www.baidu.com")
  private Resource testUrl; // 注入U(xiǎn)RL資源

  @Value("#{st.name}")
  private String studentName;

  //省略getter和setter方法

  @Override
  public String toString() {
    return "SimpleObject{" +
        "normal='" + normal + '\'' +
        ", systemPropertiesName='" + systemPropertiesName + '\'' +
        ", randomNumber=" + randomNumber +
        ", sum=" + sum +
        ", resourceFile=" + resourceFile +
        ", testUrl=" + testUrl +
        ", studentName='" + studentName + '\'' +
        '}';
  }
}

package com.hannpang;

import com.hannpang.model.SimpleObject;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class Demo04BootApplicationTests {

  @Autowired
  private SimpleObject so;

  @Test
  public void contextLoads() {
    System.out.println(so);
  }
}

app.name=一步教育

book.name=西游記
anotherfile.configinject=system

book.name.author=吳承恩

package com.hannpang.test;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;

@Component
@PropertySource(value = {"classpath:config.properties","classpath:config_${anotherfile.configinject}.properties"})
public class LoadPropsTest {

  @Value("${app.name}")
  private String appName; // 這里的值來(lái)自application.properties，spring boot啟動(dòng)時(shí)默認(rèn)加載此文件

  @Value("${book.name}")
  private String bookName; // 注入第一個(gè)配置外部文件屬性

  @Value("${book.name.author}")
  private String author; // 注入第二個(gè)配置外部文件屬性

  @Autowired
  private Environment env; // 注入環(huán)境變量對(duì)象，存儲(chǔ)注入的屬性值

  //省略getter和setter方法


  public void setAuthor(String author) {
    this.author = author;
  }


  @Override
  public String toString(){
    StringBuilder sb = new StringBuilder();
    sb.append("bookName=").append(bookName).append("\r\n")
        .append("author=").append(author).append("\r\n")
        .append("appName=").append(appName).append("\r\n")
        .append("env=").append(env).append("\r\n")
        // 從eniroment中獲取屬性值
        .append("env=").append(env.getProperty("book.name.author")).append("\r\n");
    return sb.toString();
  }

}

package com.hannpang;

import com.hannpang.model.SimpleObject;
import com.hannpang.test.LoadPropsTest;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class Demo04BootApplicationTests {

  @Autowired
  private LoadPropsTest lpt;

  @Test
  public void loadPropertiesTest() {

    System.out.println(lpt);
  }
}

// 如果屬性文件沒(méi)有app.name，則會(huì)報(bào)錯(cuò)
// @Value("${app.name}")
// private String name;

// 使用app.name設(shè)置值，如果不存在則使用默認(rèn)值
@Value("${app.name:胖先森}")
private String name;

// SpEL：調(diào)用字符串Hello World的concat方法
@Value("#{'Hello World'.concat('!')}")
private String helloWorld;

// SpEL: 調(diào)用字符串的getBytes方法，然后調(diào)用length屬性
@Value("#{'Hello World'.bytes.length}")
private String helloWorldbytes;

// SpEL: 傳入一個(gè)字符串，根據(jù)","切分后插入列表中， #{}和${}配置使用(注意單引號(hào)，注意不能反過(guò)來(lái)${}在外面，#{}在里面)
@Value("#{'${server.name}'.split(',')}")
private List<String> servers;

// SpEL: 注意不能反過(guò)來(lái)${}在外面，#{}在里面，這個(gè)會(huì)執(zhí)行失敗
@Value("${#{'HelloWorld'.concat('_')}}")
private List<String> servers2;

@Component
@ConfigurationProperties(prefix = "person")
@Validated
public class Person {
  //lastName必須是郵箱格式
  @Email
  private String lastName;

@ImportResource(locations = {"classpath:beans.xml"})
導(dǎo)入Spring的配置文件讓其生效

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
  <bean id="helloService" class="com.hanpang.springboot.service.HelloService"></bean>
</beans>

/**
 * @Configuration：指明當(dāng)前類是一個(gè)配置類；就是來(lái)替代之前的Spring配置文件
 *
 * 在配置文件中用<bean><bean/>標(biāo)簽添加組件
 * <bean id="helloService" class="com.hanpang.springboot.service.HelloService"></bean>
 */
@Configuration
public class MyAppConfig {

  //將方法的返回值添加到容器中；容器中這個(gè)組件默認(rèn)的id就是方法名
  @Bean
  public HelloService helloService02(){
    System.out.println("配置類@Bean給容器中添加組件了...");
    return new HelloService();
  }
}

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
 
import com.wx.dao.IUserDao;
import com.wx.dao.UserDaoImpl;
 
//通過(guò)該注解來(lái)表明該類是一個(gè)Spring的配置，相當(dāng)于一個(gè)傳統(tǒng)的ApplicationContext.xml
@Configuration
//相當(dāng)于配置文件里面的<context:component-scan/>標(biāo)簽,掃描這些包下面的類的注解
@ComponentScan(basePackages="com.hanpang.dao,com.hanpang.service")
public class SpringConfig {
  // 通過(guò)該注解來(lái)表明是一個(gè)Bean對(duì)象，相當(dāng)于xml中的<bean>
  //bean的id值默認(rèn)是方法名userDao
  /*
  @Bean
  public HelloService helloService02(){
    System.out.println("配置類@Bean給容器中添加組件了...");
    return new HelloService();
  }
  */
}

${random.value}、${random.int}、${random.long}
${random.int(10)}、${random.int[1024,65536]}