package dbTest;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class JDBCTest { 
    public static void main(String[] args) { 
        String driver = "com.mysql.jdbc.Driver"; 
        String dbName = "nnm5"; 
        String passwrod = "OSSDB123"; 
        String userName = "root"; 
        String url = "jdbc:mysql://localhost:13306/" + dbName; 
        String sql = "select ircnetnodeid, purpose_id,ircnetypeid from rcnetnode limit 1"; 
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        
        try { 
            Class.forName(driver); 
            //JDBC获取连接
            //Connection conn = DriverManager.getConnection(url, userName,passwrod); 
            //Druid连接池获取连接
            conn = DruidManager.getInstance().getConnection();
            ps = conn.prepareStatement(sql); 
            rs = ps.executeQuery(); 
            while (rs.next()) { 
                System.out.println("ircnetnodeid : " + rs.getInt(1) + " purpose_id : "
                        + rs.getString(2) + " ircnetypeid : " + rs.getString(3)); 
            } 
  
            // 关闭记录集 
            if (rs != null) { 
                try { 
                    rs.close(); 
                } catch (SQLException e) { 
                    e.printStackTrace(); 
                } 
            } 
  
            // 关闭声明 
            if (ps != null) { 
                try { 
                    ps.close(); 
                } catch (SQLException e) { 
                    e.printStackTrace(); 
                } 
            } 
  
            // 关闭链接对象 
            if (conn != null) { 
                try { 
                    conn.close(); 
                } catch (SQLException e) { 
                    e.printStackTrace(); 
                } 
            } 
  
        } catch (Exception e) { 
            e.printStackTrace(); 
        }finally{
        	 // 关闭记录集 
            if (rs != null) { 
                try { 
                    rs.close(); 
                } catch (SQLException e) { 
                    e.printStackTrace(); 
                } 
            } 
  
            // 关闭声明 
            if (ps != null) { 
                try { 
                    ps.close(); 
                } catch (SQLException e) { 
                    e.printStackTrace(); 
                } 
            } 
  
            // 关闭链接对象 
            if (conn != null) { 
                try { 
                    conn.close(); 
                } catch (SQLException e) { 
                    e.printStackTrace(); 
                } 
            } 
        }
        
    }   
}

package dbTest;

import java.sql.Connection;
import java.sql.SQLException;
import com.alibaba.druid.pool.DruidDataSource;

public class DruidManager {
	    private DruidManager() {}  
	    private static DruidManager single=null;
	    private DruidDataSource dataSource;

	    public synchronized  static DruidManager getInstance() {
	         if (single == null) {  
	             single = new DruidManager();
	             single.initPool();
	         }  
	        return single;
	    }
		private void initPool() {
			dataSource = new DruidDataSource();
			dataSource.setDriverClassName("com.mysql.jdbc.Driver");
			dataSource.setUsername("root");
			dataSource.setPassword("OSSDB123");
			dataSource.setUrl("jdbc:mysql://127.0.0.1:13306/nnm5");
			dataSource.setInitialSize(5);
			dataSource.setMinIdle(1);
			dataSource.setMaxActive(10);
			// 启用监控统计功能
			 try {
				dataSource.setFilters("stat");
			} catch (SQLException e) {
				
			}// for mysql
			 dataSource.setPoolPreparedStatements(false);			
		}
		
		public  Connection getConnection(){
			Connection connection = null;
			try {
				connection = dataSource.getConnection();
			} catch (SQLException e) {
				
			}
			return connection;
		}
}