直接上。。。。
还是用之前的goods表，增加了一些数据
1、实体类Goods
// 封装数据
public class Goods {
private int gid;
private String gname;
private String gprice;
private String gdate;
public int getGid() {
return gid;
}
public void setGid(int gid) {
this.gid = gid;
}
public String getGname() {
return gname;
}
public void setGname(String gname) {
this.gname = gname;
}
public String getGprice() {
return gprice;
}
public void setGprice(String gprice) {
this.gprice = gprice;
}
public String getGdate() {
return gdate;
}
public void setGdate(String gdate) {
this.gdate = gdate;
}
public Goods(int gid, String gname, String gprice, String gdate) {
super();
this.gid = gid;
this.gname = gname;
this.gprice = gprice;
this.gdate = gdate;
}
public Goods() {
super();
}
}
2、DBHelper类
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
/**
* 获取数据库操作的连接对象
* 关闭数据库操作的各种资源
* @author 晏先政
*
*/
public class DBHelper {
private static final String className = "com.mysql.jdbc.Driver";
private static final String url = "jdbc:mysql://localhost:3306/test?characterEncoding=utf8&useSSL=true";
private static final String uname = "root";
private static final String upass = "";
/**
* 获取数据库连接对象的方法
*/
public static Connection getConn(){
Connection conn = null;
try{
Class.forName(className);
conn = DriverManager.getConnection(url,uname, upass);
} catch(Exception e){
e.printStackTrace();
}
return conn;
}
/**
* 关闭数据库连接对象
*/
public static void closeConn(Connection conn){
try{
if(conn!=null){
conn.close();
}
} catch(Exception e){
e.printStackTrace();
}
}
/**
* 关闭数据库操作对象
*/
public static void closeStmt(Statement stmt){
try{
if(stmt!=null){
stmt.close();
}
} catch(Exception e){
e.printStackTrace();
}
}
/**
* 关闭数据库操作对象
*/
public static void closePstmt(PreparedStatement pstmt){
try{
if(pstmt!=null){
pstmt.close();
}
} catch(Exception e){
e.printStackTrace();
}
}
/**
* 关闭数据库操作对象
*/
public static void closeRs(ResultSet rs){
try{
if(rs!=null){
rs.close();
}
} catch(Exception e){
e.printStackTrace();
}
}
}
3、实现类GoodsDao：操作数据库进行查询
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
public class GoodsDao {
private Connection conn = null;
private PreparedStatement pstmt = null;
private ResultSet rs = null;
// 查询当前页的数据
public List getListByCurPage(int curPage){
List list = new ArrayList();
try{
conn = DBHelper.getConn();
int num = (curPage-1)*5;
String sql = "select * from goods limit "+num+",5";
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
while(rs.next()){
Goods ba = new Goods(rs.getInt("gid"),rs.getString("gname"),rs.getString("gprice"),rs.getString("gdate"));
ba.setGid(rs.getInt("gid"));
list.add(ba);
}
} catch(Exception e){
e.printStackTrace();
} finally{
DBHelper.closeRs(rs);
DBHelper.closePstmt(pstmt);
DBHelper.closeConn(conn);
}
return list;
}
// 查询所有记录的总条数
public int getCount(){
int i = 0;
try{
conn = DBHelper.getConn();
String sql = "select count(*) cnt from goods";
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
if(rs.next()){
i = rs.getInt("cnt");
}
} catch(Exception e){
e.printStackTrace();
} finally{
DBHelper.closeRs(rs);
DBHelper.closePstmt(pstmt);
DBHelper.closeConn(conn);
}
return i;
}
}
4、展示类GoodsShow
import java.util.List;
import java.util.Scanner;
public class GoodsShow {
public static void main(String[] args) {
GoodsShow bs = new GoodsShow();
bs.show();
}
private Scanner input = new Scanner(System.in);
private GoodsDao dao = new GoodsDao();
int curPage = 1;
List list = null;
public void show(){
int rowCount = dao.getCount();
int pageCount = rowCount%5==0?rowCount/5:rowCount/5+1;
list = dao.getListByCurPage(curPage);
print(list);
System.out.println("首页【F】上一页【P】下一页【N】尾页【L】请选择：");
char choose = input.next().toUpperCase().charAt(0);
switch(choose){
case 'F':
curPage = 1;
break;
case 'P':
curPage = curPage -1;
if(curPage<1){
curPage = 1;
}
break;
case 'N':
curPage = curPage +1;
if(curPage>pageCount){
curPage = pageCount;
}
break;
case 'L':
curPage = pageCount;
break;
}
show();
}
public void print(List list){
System.out.println("编号\t商品\t价格\t时间");
for(int i=0;i
System.out.println(list.get(i).getGid()+"\t"+list.get(i).getGname()+"\t"+list.get(i).getGprice()+"\t"+list.get(i).getGdate());
}
}
}
then。。。。
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