springboot获取properties文件的配置内容(转载)
1、使用@Value注解读取
读取properties配置文件时，默认读取的是application.properties。
application.properties：
demo.name=Name
demo.age=18
Java代码：
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class GatewayController {
@Value("${demo.name}")
private String name;
@Value("${demo.age}")
private String age;
@RequestMapping(value = "/gateway")
public String gateway() {
return "get properties value by ''@Value'' :" +
//1、使用@Value注解读取
" name=" + name +
" , age=" + age;
}
}
运行结果:
这里，如果要把
@Value("${demo.name}")
private String name;
@Value("${demo.age}")
private String age;
部分放到一个单独的类A中进行读取，然后在类B中调用，则要把类A增加@Component注解，并在类B中使用@Autowired自动装配类A，代码如下。
类A：
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component
public class ConfigBeanValue {
@Value("${demo.name}")
public String name;
@Value("${demo.age}")
public String age;
}
类B:
import cn.wbnull.springbootdemo.config.ConfigBeanValue;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class GatewayController {
@Autowired
private ConfigBeanValue configBeanValue;
@RequestMapping(value = "/gateway")
public String gateway() {
return "get properties value by ''@Value'' :" +
//1、使用@Value注解读取
" name=" + configBeanValue.name +
" , age=" + configBeanValue.age;
}
}
运行结果:
注意：如果@Value${}所包含的键名在application.properties配置文件中不存在的话，会抛出异常：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'configBeanValue': Injection of autowired dependencies failed;
nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'demo.name' in value "${demo.name}"
2、使用Environment读取
application.properties：
demo.sex=男
demo.address=山东
代码
import cn.wbnull.springbootdemo.config.ConfigBeanValue; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class GatewayController { @Autowired private ConfigBeanValue configBeanValue; @Autowired private Environment environment; @RequestMapping(value = "/gateway") public String gateway() { return "get properties value by ''@Value'' :" + //1、使用@Value注解读取 " name=" + configBeanValue.name + " , age=" + configBeanValue.age + "<p>get properties value by ''Environment'' :" + //2、使用Environment读取 " , sex=" + environment.getProperty("demo.sex") + " , address=" + environment.getProperty("demo.address"); } }
运行结果:
这里，我们在application.properties做如下配置：
server.tomcat.uri-encoding=UTF-8
spring.http.encoding.charset=UTF-8
spring.http.encoding.enabled=true
spring.http.encoding.force=true
spring.messages.encoding=UTF-8
重新运行结果如下:
3、使用@ConfigurationProperties注解读取
在实际项目中，当项目需要注入的变量值很多时，上述所述的两种方法工作量会变得比较大，这时候我们通常使用基于类型安全的配置方式，将properties属性和一个Bean关联在一起，即使用注解@ConfigurationProperties读取配置文件数据。
在src\main\resources下新建config.properties配置文件：
demo.phone=10086
demo.wife=self
创建ConfigBeanProp并注入config.properties中的值：
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;
@Component
@ConfigurationProperties(prefix = "demo")
@PropertySource(value = "config.properties")
public class ConfigBeanProp {
private String phone;
private String wife;
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getWife() {
return wife;
}
public void setWife(String wife) {
this.wife = wife;
}
}
@Component 表示将该类标识为Bean
@ConfigurationProperties(prefix = "demo")用于绑定属性，其中prefix表示所绑定的属性的前缀。
@PropertySource(value = "config.properties")表示配置文件路径。
使用时，先使用@Autowired自动装载ConfigBeanProp，然后再进行取值，示例如下：
import cn.wbnull.springbootdemo.config.ConfigBeanProp; import cn.wbnull.springbootdemo.config.ConfigBeanValue; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class GatewayController { @Autowired private ConfigBeanValue configBeanValue; @Autowired private Environment environment; @Autowired private ConfigBeanProp configBeanProp; @RequestMapping(value = "/gateway") public String gateway() { return "get properties value by ''@Value'' :" + //1、使用@Value注解读取 " name=" + configBeanValue.name + " , age=" + configBeanValue.age + "<p>get properties value by ''Environment'' :" + //2、使用Environment读取 " sex=" + environment.getProperty("demo.sex") + " , address=" + environment.getProperty("demo.address") + "<p>get properties value by ''@ConfigurationProperties'' :" + //3、使用@ConfigurationProperties注解读取 " phone=" + configBeanProp.getPhone() + " , wife=" + configBeanProp.getWife(); } }
运行结果:
4.使用PropertiesLoaderUtils
app-config.properties
#### 通过注册监听器(`Listeners`) + `PropertiesLoaderUtils`的方式
com.zyd.type=Springboot - Listeners
com.zyd.title=使用Listeners + PropertiesLoaderUtils获取配置文件
com.zyd.name=zyd
com.zyd.address=Beijing
com.zyd.company=in
PropertiesListener.java 用来初始化加载配置文件
package com.zyd.property.listener; import org.springframework.boot.context.event.ApplicationStartedEvent; import org.springframework.context.ApplicationListener; import com.zyd.property.config.PropertiesListenerConfig; /** * 配置文件监听器，用来加载自定义配置文件 * * @author <a href="mailto:yadong.zhang0415@gmail.com">yadong.zhang</a> * @date 2017年6月1日 下午3:38:25 * @version V1.0 * @since JDK ： 1.7 */ public class PropertiesListener implements ApplicationListener<ApplicationStartedEvent> { private String propertyFileName; public PropertiesListener(String propertyFileName) { this.propertyFileName = propertyFileName; } @Override public void onApplicationEvent(ApplicationStartedEvent event) { PropertiesListenerConfig.loadAllProperties(propertyFileName); } }
PropertiesListenerConfig.java 加载配置文件内容
package com.zyd.property.config; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.HashMap; import java.util.Map; import java.util.Properties; import org.springframework.beans.BeansException; import org.springframework.core.io.support.PropertiesLoaderUtils; /** * 第四种方式：PropertiesLoaderUtils * * @author <a href="mailto:yadong.zhang0415@gmail.com">yadong.zhang</a> * @date 2017年6月1日 下午3:32:37 * @version V1.0 * @since JDK ： 1.7 */ public class PropertiesListenerConfig { public static Map<String, String> propertiesMap = new HashMap<>(); private static void processProperties(Properties props) throws BeansException { propertiesMap = new HashMap<String, String>(); for (Object key : props.keySet()) { String keyStr = key.toString(); try { // PropertiesLoaderUtils的默认编码是ISO-8859-1,在这里转码一下 propertiesMap.put(keyStr, new String(props.getProperty(keyStr).getBytes("ISO-8859-1"), "utf-8")); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (java.lang.Exception e) { e.printStackTrace(); } } } public static void loadAllProperties(String propertyFileName) { try { Properties properties = PropertiesLoaderUtils.loadAllProperties(propertyFileName); processProperties(properties); } catch (IOException e) { e.printStackTrace(); } } public static String getProperty(String name) { return propertiesMap.get(name).toString(); } public static Map<String, String> getAllProperty() { return propertiesMap; } }
Applaction.java 启动类
package com.zyd.property; import java.io.UnsupportedEncodingException; import java.util.HashMap; import java.util.Map; 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.zyd.property.config.PropertiesListenerConfig; import com.zyd.property.listener.PropertiesListener; /** * @author <a href="mailto:yadong.zhang0415@gmail.com">yadong.zhang</a> * @date 2017年6月1日 下午3:49:30 * @version V1.0 * @since JDK ： 1.7 */ @SpringBootApplication @RestController public class Applaction { /** * * 第四种方式：通过注册监听器(`Listeners`) + `PropertiesLoaderUtils`的方式 * * @author zyd * @throws UnsupportedEncodingException * @since JDK 1.7 */ @RequestMapping("/listener") public Map<String, Object> listener() { Map<String, Object> map = new HashMap<String, Object>(); map.putAll(PropertiesListenerConfig.getAllProperty()); return map; } public static void main(String[] args) throws Exception { SpringApplication application = new SpringApplication(Applaction.class); // 第四种方式：注册监听器 application.addListeners(new PropertiesListener("app-config.properties")); application.run(args); } }
