首先抛出一个问题：如何使用Java读取到properties文件中的内容，并且把它封装到JavaBean中，以供随时使用
这就需要用到今天要说的配置绑定。
方法一：@Component+@ConfigurationProperties
1、先创建一个实体类，并加上@ConfigurationProperties注解
package demo.boot.bean; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component; /** * 只有在容器中的组件，才会拥有springboot提供的强大功能 */ @Component @ConfigurationProperties(prefix = "mycar") public class Car { private String brand; private int price; public Car() { } public Car(String brand, int price) { this.brand = brand; this.price = price; } public String getBrand() { return brand; } public void setBrand(String brand) { this.brand = brand; } public int getPrice() { return price; } public void setPrice(int price) { this.price = price; } @Override public String toString() { return "Car{" + "brand='" + brand + '\'' + ", price=" + price + '}'; } }
2、创建一个properties文件，在里面写点需要读取的东西
1. mycar.brand=BYD 2. mycar.price=300000
3、写一个控制类
package demo.boot.controller; import demo.boot.bean.Car; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; //@ResponseBody //@Controller @RestController //@ResponseBody和@Controller的合体 public class HelloController { @Autowired Car car; @RequestMapping("/car") public Car car(){ return car; } }
4、运行起来
可以看到java代码已经成功读取到properties文件里的内容，并且封装到Javabean中
方法二：@EnableConfigurationProperties+@ConfigurationProperties
1、实体类（不需要加@Component注解）
package demo.boot.bean; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component; @ConfigurationProperties(prefix = "mycar") public class Car { private String brand; private int price; public Car() { } public Car(String brand, int price) { this.brand = brand; this.price = price; } public String getBrand() { return brand; } public void setBrand(String brand) { this.brand = brand; } public int getPrice() { return price; } public void setPrice(int price) { this.price = price; } @Override public String toString() { return "Car{" + "brand='" + brand + '\'' + ", price=" + price + '}'; } }
2、配置类
package demo.boot.config; import demo.boot.bean.Car; import demo.boot.bean.Pet; import demo.boot.bean.User; import org.springframework.boot.context.properties.EnableConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /** ** 1 配置类里面使用@Bean标注在方法上给容器注册组件，默认也是单实例的 * 2 配置类本身也是组件 * 3 proxyBeanMethods:代理bean的方法 * Full(proxyBeanMethods = true) 若是组件间相互依赖，调成true * Lite(proxyBeanMethods = false) 若是组件间相互不依赖，调成false，提高运行速度 */ @Configuration(proxyBeanMethods = true) //告诉springboot这是一个配置类 @EnableConfigurationProperties(Car.class) //1 开启car的配置绑定功能 // 2 把Car这个组件自动注册到容器中去 public class MyConfig { }
3、控制器类（和方法一一样）
package demo.boot.controller; import demo.boot.bean.Car; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; //@ResponseBody //@Controller @RestController //@ResponseBody和@Controller的合体 public class HelloController { @Autowired Car car; @RequestMapping("/car") public Car car(){ return car; } }
