Java 分页
所在公司有分页组件，不过感觉没有网上看到的这个好，绑了很多公司业务上的东东再里面，所以还是大义灭亲地不说公司那个东东了，将网上看到的稍作记录，以备不时之需。
首先，最主要的一个类是 PageView ，其中封装了构造一个页面所需全部信息。如下：
public class PageView<T> {
/** 分页数据 **/
private List<T> records;
/** 页码开始索引和结束索引 **/
private PageIndex pageindex;
/** 总页数 **/
private long totalpage = 1;
/** 每页显示记录数 **/
private int maxresult = 12;
/** 当前页 **/
private int currentpage = 1;
/** 总记录数 **/
private long totalrecord;
/** 页码数量 **/
private int pagecode = 10;
public PageView(int maxresult, int currentpage) {
this.maxresult = maxresult;
this.currentpage = currentpage;
}
public void setQueryResult(QueryRst qr){
setTotalrecord(qr.getTotalRecord());
setRecords(qr.getRstList());
}
public int getPagecode() {
return pagecode;
}
public void setPagecode(int pagecode) {
this.pagecode = pagecode;
}
public long getTotalrecord() {
return totalrecord;
}
public void setTotalrecord(long totalrecord) {
this.totalrecord = totalrecord;
setTotalpage(this.totalrecord%this.maxresult==0? this.totalrecord/this.maxresult : this.totalrecord/this.maxresult+1);
}
public List<T> getRecords() {
return records;
}
public void setRecords(List<T> records) {
this.records = records;
}
public PageIndex getPageindex() {
return pageindex;
}
public long getTotalpage() {
return totalpage;
}
public void setTotalpage(long totalpage) {
this.totalpage = totalpage;
this.pageindex = WebTool.getPageIndex(pagecode, currentpage, totalpage);
}
public int getMaxresult() {
return maxresult;
}
public int getCurrentpage() {
return currentpage;
}
}
其中PageIndex，说明页码开始索引和结束索引
public class PageIndex {
private long startindex;
private long endindex;
public PageIndex(long startindex, long endindex) {
this.startindex = startindex;
this.endindex = endindex;
}
public long getStartindex() {
return startindex;
}
public void setStartindex(long startindex) {
this.startindex = startindex;
}
public long getEndindex() {
return endindex;
}
public void setEndindex(long endindex) {
this.endindex = endindex;
}
}
涉及到的getPageIndex方法为，用于确定当到达currenPage时的PageIndex状况，如下：
public static PageIndex getPageIndex(long viewpagecount, int currenPage, long totalpage){
long startpage = currenPage-(viewpagecount%2==0? viewpagecount/2-1 : viewpagecount/2);
long endpage = currenPage+viewpagecount/2;
if(startpage<1){
startpage = 1;
if(totalpage>=viewpagecount) endpage = viewpagecount;
else endpage = totalpage;
}
if(endpage>totalpage){
endpage = totalpage;
if((endpage-viewpagecount)>0) startpage = endpage-viewpagecount+1;
else startpage = 1;
}
return new PageIndex(startpage, endpage);
}
另外，将结果集总记录数放在QueryRst里面
public class QueryRst<T> {
private List<T> rstList;
private long totalrecord;
// getter & setter ...
}
使用时，
PageView<?> pageView = new PageView<?>(12,currentPage);
pageView.setQueryResult(qr);
