spring导入properties配置文件

spring导入properties配置文件

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);
    }

}