java的JDBC连接的万能版总结（dao模式）

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java的JDBC连接数据库Mysql，sqlserver, Oracle dao模式

public class BaseDao {String DBUser = "root"; // 用户名String DBPwd = "root";// 密码String DBHost = "localhost"; // 服务器地址String DBName = "myschool";// 数据库名称int Port = 3306; // 端口号int DBType = 1;    // 1mysql,2sqlserver,3orcaleConnection conn;          // 连接对象PreparedStatement ps;     // 查询对象ResultSet rs;             // 结果集/** * 打开连接 */public void open() {try {if (DBType == 1) {Class.forName("com.mysql.jdbc.Driver");conn = DriverManager.getConnection("jdbc:mysql://" + DBHost+ ":" + Port + "/" + DBName, DBUser, DBPwd);}else if (DBType == 2) {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");conn = DriverManager.getConnection("jdbc:sqlserver://" + DBHost + ":"+ Port + ";databasename=" + DBName, DBUser,DBPwd);} else if (DBType == 3) {// 编写orcalaClass.forName("Oracle.jdbc.driver.OracleDriver");conn = DriverManager.getConnection("jdbc:oracle:thin:@" + DBHost + ":"+ Port + ":" + DBName, DBUser,DBPwd);}} catch (Exception e) {// TODO: handle exception}}/** *   关闭连接 */public void close() {try {if (rs != null)rs.close(); // 如果结果集存在，就关闭结果集ps.close(); // 关闭查询对象conn.close(); // 关闭连接查询} catch (Exception e) {// TODO: handle exception}}/** * 执行 增删 * @param sql * @param parm * @return   a 为受影响的行数 */public int exectueUpdate(String sql, Object[] parm) {open();int a = 0;try {ps = conn.prepareStatement(sql);if (parm != null) {for (int i = 0; i < parm.length; i++) {ps.setObject(i + 1, parm[i]);}}a = ps.executeUpdate(); // 执行} catch (Exception e) {// TODO: handle exception}close();return a;}/** *   执行查询 * @param sql * @param parm * @return   */  public ResultSet exectueQuery(String sql,Object[] parm){  open();try {ps = conn.prepareStatement(sql);if (parm != null) {for (int i = 0; i < parm.length; i++) {ps.setObject(i + 1, parm[i]);}}   rs=ps.executeQuery();} catch (Exception e) {// TODO: handle exception} return rs;        }     }

使用继承或者new也可以

package com.xing.myschool.dao;import java.sql.SQLException;import java.util.ArrayList;import com.xing.myschool.entity.Student;public class StudentDao extends BaseDao {public int add(Student stu) {String sql = "insert into student values(?,?,?,?)";Object[] parm = { stu.getStudentid(), stu.getStudentName(),stu.getStudentSex(), stu.getStudentAge() };int a = exectueUpdate(sql, parm);return a;}public int delete(int studentId) {String sql = "delete from student where  Id=? ";Object[] parm = { studentId };int a = exectueUpdate(sql, parm);return a;}public int update(Student stu) {String sql = "update Student set name=?, age=?,sex=? where Id=?;";Object[] parm = { stu.getStudentName(), stu.getStudentAge(),stu.getStudentSex(), stu.getStudentid() };int a = exectueUpdate(sql, parm);return a;}public ArrayList<Student> getall() {String sql = "select * from student";ArrayList<Student> list = new ArrayList<Student>();rs = exectueQuery(sql, null);try {while (rs.next()) {Student stuu = new Student();stuu.setStudentid(rs.getInt("id"));stuu.setStudentName(rs.getString("name"));stuu.setStudentSex(rs.getString("sex"));stuu.setStudentAge(rs.getInt("age"));list.add(stuu);}} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}close();return list;}}

所有的代码地址：点击打开链接

使用的软件为：MyEclipse

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