java - DataSource 无法转换为 com.mchange.v2.c3p0.PooledDataSource

Question

我正在尝试使用以下代码创建 context.xml:

    ComboPooledDataSource cpds = new ComboPooledDataSource();
    try {
        cpds.setDriverClass( "net.sourceforge.jtds.jdbc.Driver" ); //loads the jdbc driver     
        cpds.setJdbcUrl( "jdbc:jtds:sqlserver://10.38.28.77/MyDB" );   
        cpds.setUser("sa");                                  
        cpds.setPassword("password");   
        cpds.setMaxStatements( 180 );
    } catch (PropertyVetoException e) {
        e.printStackTrace();
    }      
    return cpds.getConnection();

我的意思是，将此硬编码设置转换为 context.xml，如下所示:

        <Resource name="jdbc/MyDBHrd" 
         driverClass="net.sourceforge.jtds.jdbc.Driver"
         maxPoolSize="100"
         minPoolSize="15"
         acquireIncrement="1"
         auth="Container"
         maxStatements="50"
         idleConnectionTestPeriod="3600"
         testConnectionOnCheckin="true"
         automaticTestTable="connection_test"
         maxIdleTime="21600"
         factory="org.apache.naming.factory.BeanFactory"
         type="com.mchange.v2.c3p0.ComboPooledDataSource"
         jdbcUrl="jdbc:jtds:sqlserver://192.168.114.130/MyDB"
         user="sa" password="password" />

但是使用此 context.xml 时:

    InitialContext cxt = new InitialContext();
    String jndiName = "java:/comp/env/jdbc/MyDBHrd";
    // Look up our data source
    ComboPooledDataSource dataSource = (ComboPooledDataSource) cxt.lookup(jndiName);

抛出:

ClassCastException: org.apache.tomcat.dbcp.dbcp.DataSource cannot be cast to com.mchange.v2.c3p0.PooledDataSource

Answer 1

您应该将数据源声明为普通类型，而不是 Combo 类型。您要求 Tomcat 创建一个数据源，它不会为您创建其中之一。如果您需要将纯数据源包装在其中之一中，请在 Java 中执行此操作。