Java分页

JavaWeb分页的实现

2016/5/18 21:53:35 SeventeenWen

思路就是根据当前页码和每页记录数查询数据库，计算出总记录数，根据总记录数和每页记录数算出总页数，最后在页面上做分页处理。

import java.util.List;

public class PageBean<T> {

//  当前页码
private int pageCode;
//  总记录数
private int totalCode;
//  每页记录数
private int paginal;
//  当前页记录
private List<T> beanList;
//
private String url;
@Override
public String toString() {
return "PageBean [pageCode=" + pageCode + ", totalCode=" + totalCode + ", paginal=" + paginal + ", beanList="
+ beanList + ", url=" + url + "]";
}
public int getPageCode() {
return pageCode;
}
public void setPageCode(int pageCode) {
this.pageCode = pageCode;
}
public int getTotalCode() {
return totalCode;
}
public void setTotalCode(int totalCode) {
this.totalCode = totalCode;
}
public int getPaginal() {
return paginal;
}
public void setPaginal(int paginal) {
this.paginal = paginal;
}
public List<T> getBeanList() {
return beanList;
}
public void setBeanList(List<T> beanList) {
this.beanList = beanList;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}

public int getTp(){

//      计算总页数tp 总记录数除以每页记录数
int tp = totalCode/paginal;
//      总记录%每页记录数 如果有余说明有还需要加一页显示
return totalCode%paginal==0 ? tp :tp+1;
}

}

数据库查询：

/**
* 查询页数
* @return count
*/
public int findCount(){
int count=0;
try {
Connection con = JdbcUtils.getConnection();
String sql = "SELECT COUNT(*) FROM t_goods";
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(sql);
if(rs.next()){
count=rs.getInt(1);
}
rs.close();
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
return count;
}
/**
*
* 传递两个参数当前页码数，和每页记录数
* @param pageCode
* @param paginal
* @return
*/
public PageBean<Beans> findAll(int pageCode,int paginal){
PageBean<Beans> pb = new PageBean<Beans>();

pb.setPageCode(pageCode);
pb.setPaginal(paginal);
int totalCode = this.findCount();
//      得到总记录数
pb.setTotalCode(totalCode);
List<Goods> list = new ArrayList<Beans>();
try {
String sql = "select *from t_goods limit ?,?";
Connection con =JdbcUtils.getConnection();
PreparedStatement ps =con.prepareStatement(sql);
//表示查询从第value条数据到paginal条数据
int value =  (pageCode-1)*paginal;
System.out.println(value);
ps.setInt(1,value);
System.out.println(paginal);
ps.setInt(2, paginal);
ResultSet re = ps.executeQuery();
while(re.next()){
/从数据库得到的数据保存在Bean对象中
}
re.close();
ps.close();
con.close();

} catch (SQLException e) {
e.printStackTrace();
}
pb.setBeanList(list);

return pb;

}

页面：

取出在pageBean中的页码数，当前页pageBean.pageCode，全部页pageBean.tp根据这两个值就可以计算所有的需要了；