java操作数据库sqlserver（三）

第三步：实现接口方法的实现类

package com.qilu.jdbcDemo.dao.IuserImp;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import java.sql.Statement;import java.util.List;import java.util.ArrayList;import java.sql.*;import javax.swing.JOptionPane;import com.qilu.jdbcDemo.dao.IUserDao;import com.qilu.jdbcDemo.entity.User;/* *这是一个实体类，实现了IUserDao接口中的所有方法  */public class UserDaoImp implements IUserDao {//插入一条数据 --实现方法@Overridepublic int insertOneUser(User user) {int i = 0;//连接数据库try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=JDBCDemo","sa","100862");Statement stmt = conn.createStatement();//插入语句i = stmt.executeUpdate("insert into TestStudent values ("+user.getId()+",'"+user.getName()+"','"+user.getSex()+"',"+user.getAge()+")");} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return i;}//删除一条数据@Overridepublic int deleteOneUser(User user) {int i = 0;//连接数据库try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=JDBCDemo","sa","100862");Statement stmt = conn.createStatement();//插入语句i = stmt.executeUpdate("delete from TestStudent where id = " + user.getId());} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return i;}//更新一条数据@Overridepublic int updateOneUser(User user) {int i = 0;//连接数据库try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=JDBCDemo","sa","100862");//更新语句String sql = "update TestStudent set name = ?,sex = ?,age = ?  where id = ?";PreparedStatement stmt = conn.prepareStatement(sql);//设置参数stmt.setString(1, user.getName());stmt.setString(2, user.getSex());stmt.setInt(3,user.getAge());stmt.setInt(4, user.getId());i = stmt.executeUpdate(); } catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return i;}//通过userId查找一条数据@Overridepublic User findOneUser(int userId) {User user = new User();//连接数据库try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=JDBCDemo","sa","100862");Statement stmt = conn.createStatement();//得到查询的结果ResultSet rs = stmt.executeQuery("select * from TestStudent where id = "+userId );while(rs.next()){user.setId(rs.getInt("id"));user.setName(rs.getString("name"));user.setSex(rs.getString("sex"));user.setAge(rs.getInt("age"));}} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return user;}//通过userName查找一条数据@Overridepublic User frindOneUser(String userName) {User user = new User();//连接数据库try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=JDBCDemo","sa","100862");Statement stmt = conn.createStatement();//得到查询的结果ResultSet rs = stmt.executeQuery("select * from TestStudent where name = '"+userName+"'" );while(rs.next()){user.setId(rs.getInt("id"));user.setName(rs.getString("name"));user.setSex(rs.getString("sex"));user.setAge(rs.getInt("age"));}} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return user;}//查找出所有的数据@Overridepublic List<User> findAllUser() {//建立一个集合，放所有数据List<User> userList = new ArrayList<User>();//连接数据库try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=JDBCDemo","sa","100862");Statement stmt = conn.createStatement();//得到查询的结果ResultSet rs = stmt.executeQuery("select * from TestStudent");while(rs.next()){//每循环一次产生一个user对象User user = new User();user.setId(rs.getInt("id"));user.setName(rs.getString("name"));user.setSex(rs.getString("sex"));user.setAge(rs.getInt("age"));//把user放到userList集合中去userList.add(user);}} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return userList;}//验证数据是否存在@Overridepublic boolean validate(User user) {boolean b = false;//连接数据库try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=JDBCDemo","sa","100862");Statement stmt = conn.createStatement();//得到查询的结果ResultSet rs = stmt.executeQuery("select * from TestStudent where id = '"+user.getId()+"'  and name = '"+user.getName()+"'" );if(rs.next()){b = true;}} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return b;}}