标签：file ons enc prope resource div ica -- 默认值
PropertyPlaceholderConfigurer
spring提供的PropertyPlaceholderConfigurer实现类能够使Bean在配置时引用外部属性文件。
PropertyPlaceholderConfigurer实现了BeanFactoryPostProcessorBean接口，因而也是一个Bean工厂后处理器。
PropertyPlaceholderConfigurer的使用
xml配置及注解方式：
<dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>4.3.16.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.3.16.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>4.3.16.RELEASE</version> </dependency>
name=zhangsan
age=23
package test; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class Driver { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("my.xml"); User user = context.getBean("user", User.class); System.out.println(user.getName()); System.out.println(user.getAge()); } } class User { @Value("${name}") private String name; private int age; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:p="http://www.springframework.org/schema/p" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!-- spring 引入属性文件 --> <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" p:location="classpath:my.properties" p:fileEncoding="utf-8"/> <!-- 开启包扫描，因为User类使用到了@Value注解；包扫描不支持裸体类上的注解 --> <context:component-scan base-package="test"/> <!-- 使用外部属性文件值赋值 --> <bean id="user" class="test.User" p:age="${age}"/> </beans>
PropertyPlaceholderConfigurer的其他属性：
locations：可以引入多个属性文件
fileEncoding：属性文件的编码格式
order：指定多个属性的优先级
placeholderPrefix：默认值为“${”，可以修改
placeholderSuffix：默认为“}”
除了使用<bean>声明PropertyPlaceholderConfigurer引入属性文件这种方式外，还可以使用另一种简洁的方式；但如果希望自定义一些额外的高级功能，如属性加密、使用数据库表来保存配置信息时，就必须使用<bean>声明PropertyPlaceholderConfigurer的方式
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:p="http://www.springframework.org/schema/p" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!-- spring 引入属性文件 --> <context:property-placeholder location="my.properties"/> <!-- 开启包扫描，因为User类使用到了@Value注解；包扫描不支持裸体类上的注解 --> <context:component-scan base-package="test"/> <!-- 使用外部属性文件值赋值 --> <bean id="user" class="test.User" p:age="${age}"/> </beans>
Java配置及注解方式：
<dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>4.3.16.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.3.16.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>4.3.16.RELEASE</version> </dependency>
name=zhangsan
age=23
package test; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.ApplicationContext; import org.springframework.context.annotation.AnnotationConfigApplicationContext; public class Driver { public static void main(String[] args) { ApplicationContext context = new AnnotationConfigApplicationContext(MyConfig.class); User user = context.getBean("user", User.class); System.out.println(user.getName()); System.out.println(user.getAge()); } } class User { @Value("${name}") private String name; @Value("${age}") private int age; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
package test; import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.core.io.ClassPathResource; @Configuration @ComponentScan public class MyConfig { @Bean public User user() { return new User(); } @Bean public PropertyPlaceholderConfigurer PropertyPlaceholderConfigurer() { PropertyPlaceholderConfigurer configurer = new PropertyPlaceholderConfigurer(); configurer.setLocation(new ClassPathResource("my.properties")); return configurer; } }
标签：file ons enc prope resource div ica -- 默认值
原文地址：https://www.cnblogs.com/Mike_Chang/p/10276303.html
