连接池占满问题

深藏阁楼爱情的钟 2021-12-02 19:51 270阅读 0赞

**测试类：**

package com.test;
    
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    
    import com.mchange.v2.c3p0.ComboPooledDataSource;
    
    public class Test4 {
        
    	public static void main(String[] args) {
        
    
    		ComboPooledDataSource cpd = new ComboPooledDataSource();
    		Connection conn = null;
    		PreparedStatement ps = null;
    		ResultSet rs = null;
    
    		try {
        
    			Connection conn1 = cpd.getConnection();
    			Connection conn2 = cpd.getConnection();
    			Connection conn3 = cpd.getConnection();
    			Connection conn4 = cpd.getConnection();
    			Connection conn5 = cpd.getConnection();
    			System.out.println(conn1);
    			System.out.println(conn2);
    			System.out.println(conn3);
    			System.out.println(conn4);
    			System.out.println(conn5);
    			Connection conn6 = cpd.getConnection();
    
    		} catch (SQLException e) {
        
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    
    //		try {
        
    //			conn=cpd.getConnection();
    //			ps=conn.prepareStatement("select * from u_p");
    //			rs=ps.executeQuery();
    //			while(rs.next()) {
        
    //				System.out.println(rs.getInt("id")+"---"+rs.getString("username")+"---"+rs.getString("pw"));
    //			}
    //			
    //			
    //		} catch (SQLException e) {
        
    //			// TODO Auto-generated catch block
    //			e.printStackTrace();
    //		}finally {
        
    //			try {
        
    //				JDBCUtil.release(rs, ps, conn);
    //			} catch (Exception e) {
        
    //				// TODO Auto-generated catch block
    //				e.printStackTrace();
    //			}
    //		}
    
    	}
    }

c3p0-config.xml

<c3p0-config>
      
      <default-config>
      	
        <property name="driverClass">com.mysql.jdbc.Driver</property>
        <property name="jdbcUrl">jdbc:mysql://localhost:3306/jiejie</property>
        <property name="user">root</property>
        <property name="password">root</property>
        
        
        <property name="initialPoolSize">3</property>
        <property name="maxPoolSize">5</property>
        <property name="checkoutTimeout">3000</property>
      </default-config>
    </c3p0-config>