General tab (a)

General tab core ideas:
the last time the query request uh, nothing has changed except the current page.

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MySQL pagination: select * from table limit 3,3

The number of records per page set up their own
current page from the front
of the total number of pages the total number of records per page record number% == 0 Total number of records / number of records per page:? The total number of records / number of records per page +1
overall record the number of database statistics count ()
per home record number = (current page -1) * + 1 the number of records per page

Total 101 records per display 10
the first page: 1-10
second page: 11-20
third page: 21-30

The end of the number of records per page * = current number of records per page

1, a common query method code implementation

Import jar package

Before connecting to the database to see your user name, password, database name is correct

Book.java

Package com.huangyucan.util; 


public  class PageBean { 

    Private  int Page =. 1; // p 

    Private  int rows = 10; // page size 

    Private  int Total = 0; // total number of records 

    Private  Boolean the pagination = to true ; // if paging 

    public PageBean () {
         Super (); 
    } 

    public  int the getPage () {
         return Page; 
    } 

    public  void the setPage ( int Page) {
        this.page = page;
    }

    public int getRows() {
        return rows;
    }

    public void setRows(int rows) {
        this.rows = rows;
    }

    public int getTotal() {
        return total;
    }

    public void setTotal(int total) {
        this.total = total;
    }

    public void setTotal(String total) {
        this.total = Integer.parseInt(total);
    }

    public boolean isPagination() {
        return pagination;
    }

    public void setPagination(boolean pagination) {
        this.pagination = pagination;
    }

    /**
     * 获得起始记录的下标
     * 
     * @return
     */
    public int getStartIndex() {
        return (this.page - 1) * this.rows;
    }

    @Override
    public String toString() {
        return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
    }

}

BookDao.java

package com.huangyucan.dao;

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 com.zking.pageBean.entity.Book;
import com.zking.pageBean.util.BaseDao;
import com.zking.pageBean.util.BaseEntityDao;
import com.zking.pageBean.util.DBAccess;
import com.zking.pageBean.util.PageBean;
import com.zking.pageBean.util.StringUtils;

public class BookDao extends BaseEntityDao<Book>{
    
//    /**
//     * 
//     * @param book    带条件查询需要用上
//     * @param pageBean    分页
//     * @return
//     * @throws SQLException 
//     */
//    public List<Book> list(Book book,PageBean pageBean) throws SQLException{
//        List<Book> list = new ArrayList<>();
//        String sql = "select * from t_mvc_book where true";
//        if(StringUtils.isNotBlank(book.getBname())) {
//            sql += " and bname like '%"+book.getBname()+"%'";
//        }
////        System.out.println(sql);
//        Connection con = DBAccess.getConnection();
//        PreparedStatement pst = con.prepareStatement(sql);
//        ResultSet rs = pst.executeQuery();
//        while(rs.next()) {
//            list.add(new Book(rs.getInt("bid"), rs.getString("bname"), rs.getFloat("price")));
//        }
//        return list;
//    }
//    /**
//     * oop改造后的方法
//     * @param book
//     * @param pageBean
//     * @return
//     * @throws SQLException
//     * @throws IllegalAccessException 
//     * @throws InstantiationException 
//     */
//    public List<Book> list(Book book,PageBean pageBean) throws SQLException, InstantiationException, IllegalAccessException{
//        String sql = "select * from t_mvc_book where true";
//        if(StringUtils.isNotBlank(book.getBname())) {
//            sql += " and bname like '%"+book.getBname()+"%'";
//        }
//        return executeQuery(sql, pageBean, new CallBack() {
//            @Override
//            public List<Book> foreach(ResultSet rs) throws SQLException {
//                List<Book> list = new ArrayList<>();
//                while(rs.next()) {
//                    list.add(new Book(rs.getInt("bid"), rs.getString("bname"), rs.getFloat("price")));
//                }
//                return list;
//            }
//        });
SQLException@throws
     *@return
     *pageBean@param
     *Book@param
     *
     * use reflection to query the secondary enhanced/ **    }//
    
    
     *@throws InstantiationException
     * @throws IllegalAccessException
     */
    public List<Book> list(Book book,PageBean pageBean) throws SQLException, InstantiationException, IllegalAccessException{
        String sql = "select * from t_mvc_book where true";
        if(StringUtils.isNotBlank(book.getBname())) {
            sql += " and bname like '%"+book.getBname()+"%'";
        }
        return executeQuery(sql, pageBean, Book.class);
    }
    
}

BaseDao

Package com.huangyucan.util; 

Import the java.sql.Connection;
 Import java.sql.PreparedStatement;
 Import the java.sql.ResultSet;
 Import java.sql.SQLException;
 Import of java.util.ArrayList;
 Import java.util.List; 

Import com.zking.pageBean.entity.Book; 

public  class BaseDao <T> {
     / ** 
     * reference ajax callback phenomenon of 
     * the caller to handle the result set returned 
     * @author Administrator 
     * 
     * / 
    public  abstract  class the callBack {
         public  abstractList <T> the foreach (the ResultSet RS) throws SQLException, an InstantiationException is, IllegalAccessException; 
    } 
    / ** 
     * oop thinking of using a method of extracting the original query upward commonness 
     * @param SQL 
     * @param pageBean 
     * @return 
     * @throws SQLException 
     * @throws IllegalAccessException 
     * @throws an InstantiationException is 
      * / 
    public List <T> the executeQuery (String SQL, PageBean pageBean, the callBack callBack) throws SQLException, an InstantiationException is, IllegalAccessException { 
        List<T> list = new ArrayList<>();
        Connection con = DBAccess.getConnection();
        String countSql = getCountSql(sql);
        PreparedStatement pst = con.prepareStatement(countSql);
        ResultSet rs = pst.executeQuery();
        if(rs.next()) {
            pageBean.setTotal(rs.getString(1));
        }
        DBAccess.close(null, pst, rs);
        String pageSql = getPageSql(sql, pageBean);
        PreparedStatement psmt =con.prepareStatement (pageSql); 
        the ResultSet RST = psmt.executeQuery ();
         return callBack.foreach (RST); 
    } 
    / ** 
     * Get tab sql statement 
     * @param sql qualifying query 
     * @param pageBean tab entity class 
     * @return 
     * / 
    Private String getPageSql (String SQL, pageBean pageBean) {
         return SQL + "limit" pageBean.getStartIndex + () + "," + pageBean.getRows (); 
    } 
    / ** 
     * Get match the query the total number of records sql 
     * @param sql 
     * @return 
     * /
    private String getCountSql(String sql) {
        return "select count(*) from ("+ sql +") t";
    }
}

Page Tools

PageBase

Package com.huangyucan.util; 

/ ** 
 * Tools tab 
 * 
 * / 
public  class PageBean { 

    Private  int Page =. 1; // p 

    Private  int rows = 10; // page size 

    Private  int Total = 0; // total recording number 

    Private  Boolean the pagination = to true ; // if paging 

    public PageBean () {
         Super (); 
    } 

    public  int the getPage () {
         return Page; 
    } 

    public  void setPage(int page) {
        this.page = page;
    }

    public int getRows() {
        return rows;
    }

    public void setRows(int rows) {
        this.rows = rows;
    }

    public int getTotal() {
        return total;
    }

    public void setTotal(int total) {
        this.total = total;
    }

    public void setTotal(String total) {
        this.total = Integer.parseInt(total);
    }

    public boolean isPagination() {
        return pagination;
    }

    public void setPagination(boolean pagination) {
        this.pagination = pagination;
    }

    /**
     * 获得起始记录的下标
     * 
     * @return
     */
    public int getStartIndex() {
        return (this.page - 1) * this.rows;
    }

    @Override
    public String toString() {
        return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
    }

}

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