将外部属性文件的数据配置到bean的配置文件，依赖于context标签下的property-placeholder标签
1、准备properties文件
url=jdbc:mysql://localhost:3306/hibernate_db
username=root
password=1111
2、编写对应实体类
package com.yl.bean;
public class DataSource {
private String url;
private String username;
private String password;
public DataSource() {
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Override
public String toString() {
return "DataSource{" +
"url='" + url + '\'' +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
}
3、spring配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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">
<!--导入配置文件-->
<context:property-placeholder location="classpath:db.properties"></context:property-placeholder>
<!--DataSource-->
<bean id="dataSource" class="com.yl.bean.DataSource">
<property name="password" value="${password}"></property>
<property name="username" value="${username}"></property>
<property name="url" value="${url}"></property>
</bean>
</beans>
4、测试
package com.yl;
import com.yl.bean.DataSource;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainTest {
public static void main(String[] args) {
ApplicationContext applicationContext=new ClassPathXmlApplicationContext("bean1.xml");
DataSource dataSource= (DataSource) applicationContext.getBean("dataSource");
System.out.println(dataSource);
}
}
