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  • JDBC公共动作类

    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;
    
    public class DBUtil {
    	public static final String DRIVER = "com.mysql.jdbc.Driver";
    	public static final String URL = "jdbc:mysql://localhost:3306/db";
    	public static final String USERNAME = "root";
    	public static final String PASSWORD = "root";
    
    	/**
    	 * 通过静态代码块 注冊数据库驱动
    	 */
    	static {
    		try {
    			Class.forName(DRIVER);
    		} catch (ClassNotFoundException e) {
    			e.printStackTrace();
    		}
    	}
    
    	/**
    	 * 获得Connection
    	 * 
    	 * @return
    	 */
    	public static Connection getConnection() {
    		Connection conn = null;
    		try {
    			conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
    		} catch (SQLException e) {
    			e.printStackTrace();
    		}
    		return conn;
    	}
    
    	/**
    	 * 获得Statement
    	 * 
    	 * @return
    	 */
    	public static Statement getStatement() {
    		Statement st = null;
    		try {
    			st = getConnection().createStatement();
    		} catch (SQLException e) {
    			e.printStackTrace();
    		}
    		return st;
    	}
    
    	/**
    	 * 关闭ResultSet
    	 * 
    	 * @param rs
    	 */
    	public static void closeResultSet(ResultSet rs) {
    		if (rs != null) {
    			try {
    				rs.close();
    			} catch (SQLException e) {
    				e.printStackTrace();
    			}
    		}
    	}
    
    	/**
    	 * 关闭Statement
    	 * 
    	 * @param st
    	 */
    	public static void closeStatement(Statement st) {
    		if (st != null) {
    			try {
    				st.close();
    			} catch (SQLException e) {
    				e.printStackTrace();
    			}
    		}
    	}
    
    	/**
    	 * 关闭Connection
    	 * 
    	 * @param conn
    	 */
    	public static void closeConnection(Connection conn) {
    		if (conn != null) {
    			try {
    				conn.close();
    			} catch (SQLException e) {
    				e.printStackTrace();
    			}
    		}
    	}
    
    	/**
    	 * 关闭所有
    	 * 
    	 * @param rs
    	 * @param sta
    	 * @param conn
    	 */
    	public static void closeAll(ResultSet rs, Statement sta, Connection conn) {
    		closeResultSet(rs);
    		closeStatement(sta);
    		closeConnection(conn);
    	}
    
    	/**
    	 * 获得总记录数
    	 * 
    	 * @return
    	 */
    	public static int getRows() {
    		int rows = 0;
    		Statement sta = null;
    		ResultSet rs = null;
    		Connection conn = getConnection();
    		try {
    			sta = conn.createStatement();
    			rs = sta.executeQuery("select * from e_user");
    			rs.last();
    			rows = rs.getRow();
    		} catch (SQLException e) {
    			e.printStackTrace();
    		}
    		return rows;
    
    	}
    }


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  • 原文地址:https://www.cnblogs.com/lcchuguo/p/4758537.html
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