package utils;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class DBConnection {    private static final String DBDRIVER = "com.mysql.jdbc.Driver" ;            //驱动类类名    private static final String DBURL = "jdbc:mysql://localhost:3306/db_votemanage";//连接URL    private static final String DBUSER = "root" ;                                //数据库用户名    private static final String DBPASSWORD = "root";                            //数据库密码    public static Connection getConnection(){        Connection conn = null;                                                    //声明一个连接对象        try {            Class.forName(DBDRIVER);                                            //注册驱动            conn = DriverManager.getConnection(DBURL,DBUSER,DBPASSWORD);        //获得连接对象        } catch (ClassNotFoundException e) {                                    //捕获驱动类无法找到异常            e.printStackTrace();                                                } catch (SQLException e) {                                                //捕获SQL异常            e.printStackTrace();        }        return conn;    }    public static void close(Connection conn) {//关闭连接对象        if(conn != null) {                //如果conn连接对象不为空            try {                conn.close();            //关闭conn连接对象对象            } catch (SQLException e) {                e.printStackTrace();            }        }    }    public static void close(PreparedStatement pstmt) {//关闭预处理对象        if(pstmt != null) {                //如果pstmt预处理对象不为空            try {                pstmt.close();            //关闭pstmt预处理对象            } catch (SQLException e) {                e.printStackTrace();            }        }    }    public static void close(ResultSet rs) {//关闭结果集对象        if(rs != null) {                //如果rs结果集对象不为null            try {                rs.close();                //关闭rs结果集对象            } catch (SQLException e) {                e.printStackTrace();            }        }    }}

package utils;public class Page {    private int everyPage;            //每页显示记录数    private int totalCount;            //总记录数    private int totalPage;            //总页数    private int currentPage;        //当前页    private int beginIndex;            //查询起始点    private boolean hasPrePage;        //是否有上一页    private boolean hasNextPage;    //是否有下一页    public Page(int everyPage, int totalCount, int totalPage,             int currentPage,int beginIndex, boolean hasPrePage,            boolean hasNextPage) {    //自定义构造方法        this.everyPage = everyPage;        this.totalCount = totalCount;        this.totalPage = totalPage;        this.currentPage = currentPage;        this.beginIndex = beginIndex;        this.hasPrePage = hasPrePage;        this.hasNextPage = hasNextPage;    }    public Page(){}                    //默认构造函数    public int getEveryPage() {        //获得每页显示记录数        return everyPage;    }    public void setEveryPage(int everyPage) {//设置每页显示记录数        this.everyPage = everyPage;    }    public int getTotalCount() {//获得总记录数        return totalCount;    }    public void setTotalCount(int totalCount) {//设置总记录数        this.totalCount = totalCount;    }    public int getTotalPage() {//获得总页数        return totalPage;    }    public void setTotalPage(int totalPage) {//设置总页数        this.totalPage = totalPage;    }    public int getCurrentPage() {//获得当前页        return currentPage;    }    public void setCurrentPage(int currentPage) {//设置当前页        this.currentPage = currentPage;    }    public int getBeginIndex() {//获得查询起始点        return beginIndex;    }    public void setBeginIndex(int beginIndex) {//设置查询起始点        this.beginIndex = beginIndex;    }    public boolean isHasPrePage() {//获得是否有上一页        return hasPrePage;    }    public void setHasPrePage(boolean hasPrePage) {//设置是否有上一页        this.hasPrePage = hasPrePage;    }    public boolean isHasNextPage() {//获得是否有下一页        return hasNextPage;    }    public void setHasNextPage(boolean hasNextPage) {//设置是否有下一页        this.hasNextPage = hasNextPage;    }}-------------------------------------------------------------------------------package utils;/* * 分页信息辅助类 */public class PageUtil {    public static Page createPage(int everyPage,int totalCount,int currentPage) {//创建分页信息对象        everyPage = getEveryPage(everyPage);        currentPage = getCurrentPage(currentPage);        int totalPage = getTotalPage(everyPage, totalCount);        int beginIndex = getBeginIndex(everyPage, currentPage);        boolean hasPrePage = getHasPrePage(currentPage);        boolean hasNextPage = getHasNextPage(totalPage, currentPage);        return new Page(everyPage, totalCount, totalPage, currentPage,                beginIndex, hasPrePage,  hasNextPage);    }    public static int getEveryPage(int everyPage) {        //获得每页显示记录数        return everyPage == 0 ? 10 : everyPage;    }    public static int getCurrentPage(int currentPage) {    //获得当前页        return currentPage == 0 ? 1 : currentPage;    }    public static int getTotalPage(int everyPage,int totalCount) {//获得总页数        int totalPage = 0;        if(totalCount != 0 &&totalCount % everyPage == 0) {            totalPage = totalCount / everyPage;        } else {            totalPage = totalCount / everyPage + 1;        }        return totalPage;    }    public static int getBeginIndex(int everyPage,int currentPage) {//获得起始位置        return (currentPage - 1) * everyPage;    }    public static boolean getHasPrePage(int currentPage) {//获得是否有上一页        return currentPage == 1 ? false : true;    }    public static boolean getHasNextPage(int totalPage, int currentPage) {    //获得是否有上一页        return currentPage == totalPage || totalPage == 0 ? false : true;    }}