关于c3p0不想说什么了,以前研究过,但是现在给忘了,于是乎遇到了一些问题,主要关于ComboPooledDataSource 的close方法
对于数据源ComboPooledDataSource来说,调用close方法之后,就不能再继续getConnection了 因为数据源已经关闭,不能再继续使用
eg
import java.lang.reflect.InvocationTargetException; import java.sql.Connection; import java.sql.SQLException; import com.mchange.v2.c3p0.ComboPooledDataSource; public class Main { private static ComboPooledDataSource ds = null; static{ ds = new ComboPooledDataSource(); } //关掉数据源 public static void closeDataSource() throws Exception{ ds.getClass().getMethod("close").invoke(ds); } //得到connection public static Connection getConnection() throws Exception { return ds.getConnection(); } //关闭connection public static void closeConn(Connection con) throws SQLException{ con.close(); } public static void main(String[] args) throws Exception { Connection conn = getConnection(); System.out.println(conn); closeConn(conn); closeDataSource(); Connection conn2 = getConnection();//此处报错 [numThreadsAwaitingCheckoutDefaultUser] ] has been closed() -- you can no longer use it. System.out.println(conn2); closeConn(conn2); } }
输出:
com.mchange.v2.c3p0.impl.NewProxyConnection@1953895
Exception in thread "main" java.sql.SQLException: com.mchange.v2.c3p0.ComboPooledDataSource [ java.beans.IntrospectionException: java.lang.reflect.InvocationTargetException [numThreadsAwaitingCheckoutDefaultUser] ] has been closed() -- you can no longer use
it.
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.assertCpds(AbstractPoolBackedDataSource.java:495)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getPoolManager(AbstractPoolBackedDataSource.java:507)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
at Main.getConnection(Main.java:21)
at Main.main(Main.java:35)