c3p0数据源用户名密码加密或解密(Spring中配置)

spring2 配置文件 

<?xml version="1.0"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <!--  数据源配置 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        <property name="driverClass">
            <value>oracle.jdbc.driver.OracleDriver</value>
        </property>
        <property name="jdbcUrl" value="jdbc:oracle:thin:@IP:端口:SID" />
        <property name="acquireIncrement" value="1"/>
        <property name="idleConnectionTestPeriod" value="300"/>
        <property name="maxPoolSize" value="5"/>
        <property name="minPoolSize" value="1"/>
        <property name="initialPoolSize" value="1" />
        <property name="numHelperThreads" value="3"/>
        <property name="maxIdleTime" value="1200" />
        <property name="acquireRetryAttempts" value="2"/>
        <property name="preferredTestQuery" value=" select 1 from dual "/>
        <property name="testConnectionOnCheckin" value="true"/>
        [color=red]<property name="properties" ref="dataSourceProperties"/>[/color]
    </bean>

    <bean id="dataSourceProperties" class="PropertiesEncryptFactoryBean">
        <property name="properties">
            <props>
                <prop key="user">xxxx加密后</prop>
                <prop key="password">xxxxxxx加密后</prop>
            </props>
        </property>
    </bean>

2.PropertiesEncryptFactoryBean（加密类） 

import java.util.Properties;

import org.springframework.beans.factory.FactoryBean;

public class PropertiesEncryptFactoryBean implements FactoryBean {

    private Properties properties;

    public Object getObject() throws Exception {
        return getProperties();
    }

    public Class getObjectType() {
        return java.util.Properties.class;
    }

    public boolean isSingleton() {
        return true;
    }

    public Properties getProperties() {
        return properties;
    }

    public void setProperties(Properties inProperties) {
        this.properties = inProperties;
        String originalUsername = properties.getProperty("user");
        String originalPassword = properties.getProperty("password");
        if (originalUsername != null){
            String newUsername = deEncryptUsername(originalUsername);
            properties.put("user", newUsername);
        }
        if (originalPassword != null){
            String newPassword = deEncryptPassword(originalPassword);
            properties.put("password", newPassword);
        }
    }

    private String deEncryptUsername(String originalUsername){
        return deEncryptString(originalUsername);
    }

    private String deEncryptPassword(String originalPassword){
        return deEncryptString(originalPassword);
    }
    //简单加密
    private String deEncryptString(String originalString){
        StringBuilder newString = new StringBuilder();
        for (int i = 0; i < originalString.length(); i++) {
            char eachChar= originalString.charAt(i);
            char newChar = (char)(eachChar + i);
            newString.append(newChar);
        }
        return newString.toString();
    }

}

ComboPooledDataSource的properties属性可被注入user,password 
只有user，password两个属性是可配置，其他属性不存也不是取自properties（具体可看C3P0源码）