jsp+mysql项目源码

package com.db; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; /* * @auther:sun * date:11-16-afternoon * desc:数据库连接类 * */ public class DB { private static String driver = "com.mysql.jdbc.Driver"; private static String url = "jdbc:mysql://localhost/log"; private static String user = "root"; private static String pwd = "mysql"; private static Connection conn = null; private static Statement stmt = null; private static PreparedStatement pstmt = null; private static ResultSet rs = null; /*构造方法*/ public DB(){ conn = getConnection(); } /*内部方法，用于获得与数据库连接*/ private Connection getConnection(){ try { Class.forName(driver).newInstance(); conn = DriverManager.getConnection(url, user, pwd); } catch (InstantiationException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalAccessException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return conn; } /*内部方法，用于得到statement*/ private Statement getStatement(){ try { stmt = getConnection().createStatement(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return stmt; } /*外部方法，用于得到初始化完的preparedstatement*/ public PreparedStatement getPreStatement(String sql,Object...o){ try { pstmt = getConnection().prepareStatement(sql); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } for (int i = 0; i < o.length; i++) { try { pstmt.setObject(i+1, o[i]); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return pstmt; } /*外部方法，用于stmt的查询*/ public ResultSet select(String sql){ try { rs = getStatement().executeQuery(sql); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return rs; } /*外部方法，用于preparedstatement的查询*/ public ResultSet select(String sql,Object...o){ try { rs = getPreStatement(sql, o).executeQuery(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return rs; } /*外部方法，用于stmt的增删改*/ public int update(String sql){ int i = 0; try { i = getStatement().executeUpdate(sql); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return i; } /*外部方法，用于preparedstatement的增删改*/ public int update(String sql,Object...o){ int i = 0; try { i = getPreStatement(sql, o).executeUpdate(); } catch (SQLException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } return i; } /*外部方法，用于处理事务*/ public int update(PreparedStatement[] pstmt){ try { conn.setAutoCommit(false); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } int j = 0; for (int i = 0; i < pstmt.length; i++) { try { j = pstmt[i].executeUpdate() + j; if (j == 0) { conn.rollback(); return 0; } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { conn.setAutoCommit(true); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return j; } //该方法主要用来关闭自动提交 public void closeAutoSubmit(){ try { conn.setAutoCommit(false); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } //该方法主要用来打开自动提交 public void openAutoSubmit(){ try { conn.commit(); conn.setAutoCommit(true); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /*外部方法，用于关闭连接*/ public void close(){ try { if (rs != null) { rs.close(); } if (stmt != null) { stmt.close(); } if (pstmt != null) { pstmt.close(); } if (conn != null) { conn.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }