c3p0连接Mysql通过读取配置文件实现

骑猪看日落 2023-06-20 04:57 13阅读 0赞

**序言：本次开发完全在IDEA下。**

## 新建XML文件 ##

#### IDEA下新建XML文件 ####

默认IDEA下是没有XML文件的，需要自己手动添加配置模板，添加过程如下。

*  第一步  
    点击左上角File---->settings…
 *  第二步  
    选择Editor—>File And Code Templates—>中间选中Files
 *  第三步  
    按下图进行操作。  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5Mzk3MTY1_size_16_color_FFFFFF_t_70]
 *  第四步  
    点击File—>New—>找到XML文件，创建XML文件。

## XML文件配置 ##

<?xml version="1.0" encoding="UTF-8" ?>
    <c3p0-config>
        <named-config name="Test_c3p0">
        
        <property name="jdbcUrl">jdbc:mysql://localhost:3306/world?useSSL=false&rewriteBatchedStatement=true</property>
        <property name="driverClass">com.mysql.jdbc.Driver</property>
        <property name="user">root</property>
        <property name="password">123456</property>
        
        <property name="initialPoolSize">6</property>
        
        <property name="maxPoolSize">50</property>
        
        <property name="maxIdleTime">1000</property>
        </named-config>
    </c3p0-config>

**这里面有个点需要注意，我在调试的时候就遇到了这个问题。**  
**jdbUrl再写的时候要注意其中的&符号，这个符号需要加amp;来进行使用，要不会读取配置失败**

## 测试代码 ##

@Test
        public void TEST2C3P0(){ 
            ComboPooledDataSource cpds = new ComboPooledDataSource("Test_c3p0");
            Connection conn = null;
            try { 
                conn = cpds.getConnection();
            } catch (SQLException e) { 
                e.printStackTrace();
            }
            System.out.println(conn);
        }

**打印LOG如下：**

十二月 07, 2019 5:42:19 下午 com.mchange.v2.log.MLog <clinit>
    信息: MLog clients using java 1.4+ standard logging.
    十二月 07, 2019 5:42:23 下午 com.mchange.v2.c3p0.C3P0Registry banner
    信息: Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug? true; trace: 10]
    十二月 07, 2019 5:42:23 下午 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
    信息: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> Hello, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1hgeby9a61q2v0zq1s689jh|762efe5d, idleConnectionTestPeriod -> 0, initialPoolSize -> 6, jdbcUrl -> jdbc:mysql://localhost:3306/world?useSSL=false&rewriteBatchedStatement=true, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 1000, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 50, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 3, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> { user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
    com.mchange.v2.c3p0.impl.NewProxyConnection@3cb5cdba

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5Mzk3MTY1_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/2019120717472571.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5Mzk3MTY1,size_16,color_FFFFFF,t_70