jsp（数据库连接初步和javabean）

Dao包

 

package cn.hdu.dao;import java.sql.SQLException;import java.util.List;import cn.hdu.entity.Test;public interface TestDao {public int save(Test t) throws ClassNotFoundException, SQLException;public List<Test> selectAll() throws ClassNotFoundException, SQLException;public void del(String username)throws ClassNotFoundException, SQLException;}

 

 

daoimp包

package cn.hdu.daoimp;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import cn.hdu.dao.TestDao;import cn.hdu.entity.Test;import cn.hdu.util.ConnectionUtil;public class TestDaoImp implements TestDao {private ConnectionUtil mycon=null;private Connection con=null;private final String SAVESQL="insert into test1 (username,password,sex,city,hobby,text_one) values(?,?,?,?,?,?)";private final String SELECTSQL="select * from test1";private final String DELSQL="delete from test1 where username=?";public void del(String username) throws ClassNotFoundException, SQLException{// TODO Auto-generated method stubmycon=ConnectionUtil.getConnectionUtil(); con=mycon.getCon(); PreparedStatement pre=con.prepareStatement(this.DELSQL);pre.setString(1, username);pre.executeUpdate();mycon.closeCon_Pre_Res(null, pre, con);}public List<Test> selectAll() throws ClassNotFoundException, SQLException {// TODO Auto-generated method stubmycon=ConnectionUtil.getConnectionUtil(); con=mycon.getCon(); PreparedStatement pre=con.prepareStatement(this.SELECTSQL);ResultSet res=pre.executeQuery();List<Test> list=new ArrayList<Test>();while(res.next()){Test t=new Test();t.setUsername((res.getString(1)));t.setPassword((res.getString(2)));t.setSex((res.getString(3)));t.setCity((res.getString(4)));t.setHobby((res.getString(5)));t.setText_one((res.getString(6)));list.add(t);}mycon.closeCon_Pre_Res(res, pre, con);return list;}public int save(Test t) throws ClassNotFoundException, SQLException {// TODO Auto-generated method stubmycon=ConnectionUtil.getConnectionUtil(); con=mycon.getCon(); PreparedStatement pre=con.prepareStatement(this.SAVESQL);pre.setString(1,t.getUsername());pre.setString(2,t.getPassword());pre.setString(3,t.getSex());pre.setString(4,t.getCity());pre.setString(5,t.getHobby());pre.setString(6,t.getText_one());int i=pre.executeUpdate();return i;}/*public static void main(String args[]) {TestDaoImp td=new TestDaoImp();try {td.del("a");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}System.out.println("success..");try {List<Test> list=td.selectAll();for(Test tt:list) {System.out.println(tt.getUsername());}} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}Test t=new Test("b","bb","b","b","b","b");try {int i=td.save(t);if(i<1){System.out.println("没插进去.");}else{System.out.println("success.");}} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}*/}

 

 

entity包

package cn.hdu.entity;public class Test {private String username;private String password;private String sex;private String city;private String hobby;private String text_one;public Test(){}public Test(String username,String password,String sex,String city,String hobby,String text_one){this.username=username;this.password=password;this.sex=sex;this.city=city;this.hobby=hobby;this.text_one=text_one;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public String getCity() {return city;}public void setCity(String city) {this.city = city;}public String getHobby() {return hobby;}public void setHobby(String hobby) {this.hobby = hobby;}public String getText_one() {return text_one;}public void setText_one(String text_one) {this.text_one = text_one;}}

 

 

 

 

util包

package cn.hdu.util;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class ConnectionUtil {private String url="jdbc:mysql://127.0.0.1/hdu";private String username="root";private String password="123456";private static ConnectionUtil mycon=null;private Connection con=null;private ConnectionUtil() throws ClassNotFoundException{Class.forName("com.mysql.jdbc.Driver");}public static ConnectionUtil getConnectionUtil() throws ClassNotFoundException {if(mycon==null) {mycon=new ConnectionUtil();}return mycon;}public Connection getCon() throws SQLException{con=DriverManager.getConnection(url,username,password);return con;}public void closeCon_Pre_Res(ResultSet res,PreparedStatement pre,Connection con) throws SQLException {if(res!=null) {res.close();}if(pre!=null) {pre.close();}if(con!=null) {con.close();con=null;}}}