Java Spring用properties配置数据库连接池出现错误的处理方法[图]

错误

org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 17 in XML document from class path resource [db-config.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 17; columnNumber: 78; cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'contest:property-placeholder'.

保存数据库用户名等信息的properties文件

1mysql-username=root
2mysql-password=abcd2020
3mysql-jdbcUrl=jdbc:mysql://192.168.3.16/beers
4mysql-driverClass=com.mysql.jdbc.Driver

Java的测试类

1package com.mars.springtest;
2
3import org.junit.Test;
4import org.springframework.context.ConfigurableApplicationContext;
5import org.springframework.context.support.ClassPathXmlApplicationContext;
6
7import javax.sql.DataSource;
8import java.sql.SQLException;
9
10public class BeerTest {
11    ConfigurableApplicationContext ioc=new ClassPathXmlApplicationContext("db-config.xml");
12    @Test
13    public void test() throws SQLException {
14       DataSource bean= (DataSource) ioc.getBean("mysql-pool");
15        System.out.println(bean.getConnection());
16    }
17}

出错时的spring的xml配置文件

1<?xml version="1.0" encoding="UTF-8"?>
2<beans xmlns="http://www.springframework.org/schema/beans"
3       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4       xmlns:contest="http://www.springframework.org/schema/context"
5       xsi:schemaLocation="http://www.springframework.org/schema/beans
6       http://www.springframework.org/schema/beans/spring-beans.xsd">
7
8
9    <contest:property-placeholder location="classpath:db-config.properties"/>
10    <bean id="mysql-pool" class="com.mchange.v2.c3p0.ComboPooledDataSource">
11        <property name="user" value="${mysql-username}"></property>
12        <property name="password" value="${mysql-password}"></property>
13        <property name="jdbcUrl" value="${mysql-jdbcUrl}"></property>
14        <property name="driverClass" value="${mysql-driverClass}"></property>
15    </bean>
16</beans>

更正之后的spring的配置文件。注意红色的两行默认是没有，加上这两行就Ok了

1<?xml version="1.0" encoding="UTF-8"?>
2<beans xmlns="http://www.springframework.org/schema/beans"
3       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4       xmlns:contest="http://www.springframework.org/schema/context"
5       xsi:schemaLocation="http://www.springframework.org/schema/beans
6       http://www.springframework.org/schema/beans/spring-beans.xsd
7       http://www.springframework.org/schema/context
8       http://www.springframework.org/schema/context/spring-context.xsd">
9
10    <contest:property-placeholder location="classpath:db-config.properties"/>
11    <bean id="mysql-pool" class="com.mchange.v2.c3p0.ComboPooledDataSource">
12        <property name="user" value="${mysql-username}"></property>
13        <property name="password" value="${mysql-password}"></property>
14        <property name="jdbcUrl" value="${mysql-jdbcUrl}"></property>
15        <property name="driverClass" value="${mysql-driverClass}"></property>
16    </bean>
17</beans>

后记

2020年2月21日 农历正月2020年正月二八 星期五 凌晨3点 上海 晴