Java使用JDBC连接数据库完整的工具类实例

ゝ一纸荒年。 2022-06-14 05:52 255阅读 0赞

package com.lanp.ajax.db;
    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    
    /**
     * 连接数据库的工具类,被定义成不可继承且是私有访问
     * @author lanp
     * @since 2012-2-29 22:27
     */
    public final class DBUtils {
    	private static String url = "jdbc:mysql://localhost:3306/mydb";
    	private static String user = "root";
    	private static String psw = "root";
    	
    	private static  Connection conn;
    	
    	static {
    		try {
    			Class.forName("com.mysql.jdbc.Driver");
    		} catch (ClassNotFoundException e) {
    			e.printStackTrace();
    			throw new RuntimeException(e);
    		}
    	}
    	
    	private DBUtils() {
    		
    	}
    	
    	/**
    	 * 获取数据库的连接
    	 * @return conn
    	 */
    	public static Connection getConnection() {
    		if(null == conn) {
    			try {
    				conn = DriverManager.getConnection(url, user, psw);
    			} catch (SQLException e) {
    				e.printStackTrace();
    				throw new RuntimeException(e);
    			}
    		}
    		return conn;
    	}
    	
    	/**
    	 * 释放资源
    	 * @param conn
    	 * @param pstmt
    	 * @param rs
    	 */
    	public static void closeResources(Connection conn,PreparedStatement pstmt,ResultSet rs) {
    		if(null != rs) {
    			try {
    				rs.close();
    			} catch (SQLException e) {
    				e.printStackTrace();
    				throw new RuntimeException(e);
    			} finally {
    				if(null != pstmt) {
    					try {
    						pstmt.close();
    					} catch (SQLException e) {
    						e.printStackTrace();
    						throw new RuntimeException(e);
    					} finally {
    						if(null != conn) {
    							try {
    								conn.close();
    							} catch (SQLException e) {
    								e.printStackTrace();
    								throw new RuntimeException(e);
    							}
    						}
    					}
    				}
    			}
    		}
    	}
    }

OK，TKS！