数据库操作(存着用来复制省的每次写)

首先是：

/Vote/src/db.properties 配置文件信息(key-value形式)

driver=com.mysql.jdbc.Driverdburl=jdbc:mysql://localhost:3306/vote?useUnicode=true&characterEncoding=utf8dbuser=rootpassword=root

接着是工厂类：

/Vote/src/vote/db/ConnectionFactory.java

作用：得到配置文件的信息进行数据库的连接

package vote.db;import java.io.IOException;import java.io.InputStream;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import java.util.Properties;public class ConnectionFactory {public static String driver;public static  String dburl;public static  String dbuser;public static  String password;public static  ConnectionFactory factory = null;public ConnectionFactory(){this.getproperties();}public  void getproperties() {// TODO 自动生成的方法存根Properties prop = new Properties();//通过类方法得到Properties配置文件信息InputStream inputStream = Thread.currentThread().getContextClassLoader().getResourceAsStream("db.properties");try {prop.load(inputStream);this.driver = prop.getProperty("driver");this.dburl = prop.getProperty("dburl");this.dbuser = prop.getProperty("dbuser");this.password = prop.getProperty("password");//this.password = "";} catch (IOException e) {e.printStackTrace();}}public static Connection getConnection(){Connection conn = null;new ConnectionFactory();try {Class.forName(driver);} catch (ClassNotFoundException e) {e.printStackTrace();}try {conn = DriverManager.getConnection(dburl,dbuser,password);System.out.println("进去得到数据库");} catch (SQLException e) {e.printStackTrace();}return conn;}}

接下来是curl(增删改查) 

/Vote/src/vote/db/ControlDB.java

功能：通过自己的需求实现相应的方法，这里给出之前投票系统的一些需求方法

package vote.db;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.util.ArrayList;import java.util.List;import values.ApplyValue;import values.VoteInfoValue;public class ControlDB {//public List executeQueryRole(String sql) throws Exception {//ResultSet rs = null;//List list = new ArrayList();//Connection con = null;//Statement stmt = null;//try {//con = ConnectionFactory.getConnection();//stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,//ResultSet.CONCUR_UPDATABLE);//rs = stmt.executeQuery(sql);//while (rs.next()) {//Role role = new Role();//int i = 1;//role.setId(rs.getInt(i++));//role.setAdmins(rs.getString(i++));//role.setPass(rs.getString(i++));//role.setSitename(rs.getString(i++));//role.setCheck(rs.getInt(i++));//role.setVotename(rs.getString(i++));//list.add(role);//}//} catch (Exception e) {//throw e;//} finally {//DatabaseUtils.closeObject(rs, stmt, con);//}//return list;//}public boolean executeQueryToVote(String sql) throws Exception {boolean temp=false;ResultSet rs = null;Connection con = null;PreparedStatement ps=null;try {con = ConnectionFactory.getConnection();ps=con.prepareStatement(sql);rs = ps.executeQuery(sql);System.out.println("在executeQueryToVote里面");while (rs.next()) {temp=true;}} catch (Exception e) {throw e;} finally {CloseDateBase.closeObject(rs, ps, con);}System.out.println(temp);return temp;}public List<ApplyValue> executeQueryVoteIfoVal(String sql) throws Exception {ResultSet rs = null;List list = new ArrayList();Connection con = null;PreparedStatement ps=null;//Statement stmt = null;try {//Class.forName(driverName);////2.得到连接//cn=DriverManager.getConnection(url,"root","root");//System.out.println("111");//PreparedStatement ps=cn.prepareStatement(sql);//////ps.setObject(1, userid);//ps.setObject(2, password);//ResultSet rs=null;//rs=ps.executeQuery();////if(rs.next()){con = ConnectionFactory.getConnection();ps=con.prepareStatement(sql);rs = ps.executeQuery(sql);System.out.println("在得链表的db里面");//while(rs.next()){//FdyValue fv=new FdyValue();//fv.setT_name(rs.getString("t_name"));//fv.setT_password(rs.getString("t_password"));//fv.setT_user(rs.getString("t_user"));//fv.setT_grade(rs.getString("t_grade"));//System.out.println("执行赋值操作");//fdyList.add(fv);//while (rs.next()) {System.out.println("准备拿到");VoteInfoValue vote = new VoteInfoValue();vote.setvId(rs.getInt("vId"));vote.setvStuId(rs.getString("vStuId"));vote.setvApyId(rs.getString("vApyId"));vote.setvTime(rs.getString("vTime"));list.add(vote);System.out.println("成功拿到");}} catch (Exception e) {throw e;} finally {CloseDateBase.closeObject(rs, ps, con);}return list;}public List<ApplyValue> executeQueryVote(String sql) throws Exception {ResultSet rs = null;List<ApplyValue> list = new ArrayList<ApplyValue>();Connection con = null;PreparedStatement ps=null;//Statement stmt = null;try {//Class.forName(driverName);////2.得到连接//cn=DriverManager.getConnection(url,"root","root");//System.out.println("111");//PreparedStatement ps=cn.prepareStatement(sql);//////ps.setObject(1, userid);//ps.setObject(2, password);//ResultSet rs=null;//rs=ps.executeQuery();////if(rs.next()){con = ConnectionFactory.getConnection();ps=con.prepareStatement(sql);rs = ps.executeQuery(sql);System.out.println("在得链表的db里面");//while(rs.next()){//FdyValue fv=new FdyValue();//fv.setT_name(rs.getString("t_name"));//fv.setT_password(rs.getString("t_password"));//fv.setT_user(rs.getString("t_user"));//fv.setT_grade(rs.getString("t_grade"));//System.out.println("执行赋值操作");//fdyList.add(fv);//while (rs.next()) {System.out.println("准备拿到");ApplyValue vote = new ApplyValue();vote.setA_id(rs.getInt("apId"));vote.setA_stuid(rs.getString("apStuId"));vote.setA_name(rs.getString("apname"));vote.setA_isOk(rs.getInt("apisOK"));vote.setA_job(rs.getInt("apType"));vote.setVcount(rs.getInt("apCount"));vote.setSex(rs.getString("sex"));vote.setZzmm(rs.getString("zzmm"));vote.setSzbm(rs.getString("szbm"));vote.setXrzw(rs.getString("xrzw"));vote.setFirstApp(rs.getString("firstApp"));vote.setSecondApp(rs.getString("secondApp"));vote.setDifferent(rs.getString("different"));vote.setActivities(rs.getString("activities"));vote.setWorkAndValue(rs.getString("workAndValue"));vote.setAwards(rs.getString("awards"));vote.setBirthday(rs.getString("birthday"));vote.setPhone(rs.getString("phone"));vote.setQq(rs.getString("qq"));vote.setScore(rs.getString("score"));vote.setRank(rs.getString("rank"));vote.setSums(rs.getString("sums"));vote.setSum(rs.getString("sum"));vote.setInfo(rs.getString("info"));vote.setObey(rs.getString("obey"));list.add(vote);System.out.println("成功拿到");}} catch (Exception e) {throw e;} finally {CloseDateBase.closeObject(rs, ps, con);}return list;}public int executeQueryVoteCounts(String sql) throws Exception {ResultSet rs = null;//List<ApplyValue> list = new ArrayList<ApplyValue>();Connection con = null;PreparedStatement ps=null;int num = 0;try {con = ConnectionFactory.getConnection();ps=con.prepareStatement(sql);rs = ps.executeQuery(sql);while (rs.next()) {num = rs.getInt(1);}System.out.println("得到sum了");System.out.println(num);} catch (Exception e) {throw e;} finally {CloseDateBase.closeObject(rs, ps, con);}return num;}public String GetexecuteQueryShuJiStudentName(String sql) throws Exception {ResultSet rs = null;//List<ApplyValue> list = new ArrayList<ApplyValue>();Connection con = null;PreparedStatement ps=null;String name=null;try {con = ConnectionFactory.getConnection();ps=con.prepareStatement(sql);rs = ps.executeQuery(sql);while (rs.next()) {name = rs.getString("sname");//这边可能需要修改}System.out.println("得到sum了");System.out.println(name);} catch (Exception e) {throw e;} finally {CloseDateBase.closeObject(rs, ps, con);}return name;}public void executeUpdate(String sql) throws Exception {//ResultSet rs = null;Connection con = null;PreparedStatement ps=null;try {con = ConnectionFactory.getConnection();ps=con.prepareStatement(sql);ps.executeUpdate(sql);} catch (Exception ex) {ex.printStackTrace();} finally {CloseDateBase.closeObject( ps, con);}}}

最后记得数据的关闭

/Vote/src/vote/db/CloseDateBase.java

package vote.db;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.Statement;public class CloseDateBase {public static void closeObject(ResultSet rs, PreparedStatement ps, Connection con) {closeObject(rs);closeObject(ps, con);}public static void closeObject(PreparedStatement ps, Connection con) {closeObject(ps);closeObject(con);}public static void closeObject(Connection con) {try {if (con != null) {con.close();}} catch (Exception e) {}}public static void closeObject(ResultSet rs) {try {if (rs != null) {rs.close();}} catch (Exception e) {}}public static void closeObject(PreparedStatement ps) {try {if (ps != null) {ps.close();}} catch (Exception e) {}}}

到此就差不多结束了；当然为了让读者认识更深入

讲下mvc 

一般 ：

创建model

userDAO类写接口

userDAOIMPL实现接口

这些接口要的方法可以就是上面数据库增删改查的方法；

举个例子

package vote.dao;public interface UserDao {public String checkRegister(String stuid);//根据学号得到用户名判断用户名是否一样public boolean checkRegStuid(String stuid);//判断学号是否存在public boolean checkInfo(String stuid,String password);public void updateLoginTime(String stuid);public void insertNewUser(String stuid,String stuName,String password, String email);}

package dao.impl;import vote.dao.UserDao;import vote.db.ControlDB;import vote.utils.ConvertUtil;//用户信息public class UserDaoImpl implements UserDao {ControlDB controlDB = null;public UserDaoImpl() {controlDB = new ControlDB();}@Overridepublic boolean checkInfo(String stuid, String password) {boolean temp=false;String sql = "  SELECT * FROM `UserInfo` WHERE `stuId` = "+stuid+" and `stuPass` ="+"'"+password+"'";System.out.println(sql);try {temp = controlDB.executeQueryToVote(sql);} catch (Exception e) {e.printStackTrace();}return temp;}public void updateLoginTime(String stuid) {// TODO 自动生成的方法存根ConvertUtil cu=new ConvertUtil();String nowtime=cu.getTime();String sql = " UPDATE `UserInfo` SET `lastLogin`='"+nowtime+"' WHERE `stuId` ="+ stuid;System.out.println("the update sql="+sql);try {System.out.println("执行更新语句");controlDB.executeUpdate(sql);} catch (Exception e) {e.printStackTrace();}}@Overridepublic void insertNewUser(String stuid, String stuName, String password ,String email) {// TODO 自动生成的方法存根ConvertUtil cu=new ConvertUtil();String nowtime=cu.getTime();String sql = "insert  into UserInfo values (null,'"+stuName+"','"+password+"',"+"'"+nowtime+"','"+stuid+"','"+email+"')";System.out.println(sql);try {System.out.println("执行增加user语句");controlDB.executeUpdate(sql);} catch (Exception e) {e.printStackTrace();}}@Overridepublic String checkRegister(String stuid) {String name=null;String sql = "  SELECT * FROM `student` WHERE `sno` = "+stuid;System.out.println(sql);try {name = controlDB.GetexecuteQueryShuJiStudentName(sql);} catch (Exception e) {e.printStackTrace();}return name;}@Overridepublic boolean checkRegStuid(String stuid) {boolean temp=false;String sql = "  SELECT * FROM `userInfo` WHERE `stuId` = "+stuid;System.out.println(sql);try {temp = controlDB.executeQueryToVote(sql);} catch (Exception e) {e.printStackTrace();}return temp;}}

如果还有什么疑问 欢迎拍砖^_^