java 对List进行物理分页

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package controller.groupbuying.navigate; /**
*
* @author fee
* @date 2011-03-31 12:39:07
* @copyright 广州互动生活网络科技有限公司
*/
import java.util.ArrayList;
import java.util.List; public class PageModel { private int page = 1; // 当前页
public int totalPages = 0; // 总页数
private int pageRecorders;// 每页5条数据
private int totalRows = 0; // 总数据数
private int pageStartRow = 0;// 每页的起始数
private int pageEndRow = 0; // 每页显示数据的终止数
private boolean hasNextPage = false; // 是否有下一页
private boolean hasPreviousPage = false; // 是否有前一页
private List list; // private Iterator it;
public PageModel(List list, int pageRecorders) {
init(list, pageRecorders);// 通过对象集,记录总数划分
} /** */
/**
* 初始化list,并告之该list每页的记录数
* @param list
* @param pageRecorders
*/
public void init(List list, int pageRecorders) {
this.pageRecorders = pageRecorders;
this.list = list;
totalRows = list.size();
// it = list.iterator();
hasPreviousPage = false;
if ((totalRows % pageRecorders) == 0) {
totalPages = totalRows / pageRecorders;
} else {
totalPages = totalRows / pageRecorders + 1;
} if (page >= totalPages) {
hasNextPage = false;
} else {
hasNextPage = true;
} if (totalRows < pageRecorders) {
this.pageStartRow = 0;
this.pageEndRow = totalRows;
} else {
this.pageStartRow = 0;
this.pageEndRow = pageRecorders;
}
} // 判断要不要分页
public boolean isNext() {
return list.size() > 5;
} public void setHasPreviousPage(boolean hasPreviousPage) {
this.hasPreviousPage = hasPreviousPage;
} public String toString(int temp) {
String str = Integer.toString(temp);
return str;
} public void description() { String description = "共有数据数:" + this.getTotalRows()
+ "共有页数: " + this.getTotalPages()
+ "当前页数为:" + this.getPage()
+ " 是否有前一页: " + this.isHasPreviousPage()
+ " 是否有下一页:" + this.isHasNextPage()
+ " 开始行数:" + this.getPageStartRow()
+ " 终止行数:" + this.getPageEndRow(); System.out.println(description);
} public List getNextPage() {
page = page + 1; disposePage(); System.out.println("用户凋用的是第" + page + "页");
this.description();
return getObjects(page);
} /** */
/**
* 处理分页
*/
private void disposePage() { if (page == 0) {
page = 1;
} if ((page - 1) > 0) {
hasPreviousPage = true;
} else {
hasPreviousPage = false;
} if (page >= totalPages) {
hasNextPage = false;
} else {
hasNextPage = true;
}
} public List getPreviousPage() { page = page - 1; if ((page - 1) > 0) {
hasPreviousPage = true;
} else {
hasPreviousPage = false;
}
if (page >= totalPages) {
hasNextPage = false;
} else {
hasNextPage = true;
}
this.description();
return getObjects(page);
} /** */
/**
* 获取第几页的内容
*
* @param page
* @return
*/
public List getObjects(int page) {
if (page == 0) {
this.setPage(1);
} else {
this.setPage(page);
}
this.disposePage();
if (page * pageRecorders < totalRows) {// 判断是否为最后一页
pageEndRow = page * pageRecorders;
pageStartRow = pageEndRow - pageRecorders;
} else {
pageEndRow = totalRows;
pageStartRow = pageRecorders * (totalPages - 1);
} List objects = null;
if (!list.isEmpty()) {
objects = list.subList(pageStartRow, pageEndRow);
}
//this.description();
return objects;
} public List getFistPage() {
if (this.isNext()) {
return list.subList(0, pageRecorders);
} else {
return list;
}
} public boolean isHasNextPage() {
return hasNextPage;
} public void setHasNextPage(boolean hasNextPage) {
this.hasNextPage = hasNextPage;
} public List getList() {
return list;
} public void setList(List list) {
this.list = list;
} public int getPage() {
return page;
} public void setPage(int page) {
this.page = page;
} public int getPageEndRow() {
return pageEndRow;
} public void setPageEndRow(int pageEndRow) {
this.pageEndRow = pageEndRow;
} public int getPageRecorders() {
return pageRecorders;
} public void setPageRecorders(int pageRecorders) {
this.pageRecorders = pageRecorders;
} public int getPageStartRow() {
return pageStartRow;
} public void setPageStartRow(int pageStartRow) {
this.pageStartRow = pageStartRow;
} public int getTotalPages() {
return totalPages;
} public void setTotalPages(int totalPages) {
this.totalPages = totalPages;
} public int getTotalRows() {
return totalRows;
} public void setTotalRows(int totalRows) {
this.totalRows = totalRows;
} public boolean isHasPreviousPage() {
return hasPreviousPage;
} public static void main(String[] args) { List<String> list = new ArrayList<String>();
list.add("a");
list.add("b");
list.add("c");
list.add("d");
list.add("e");
list.add("f");
list.add("g");
list.add("h");
list.add("h");
list.add("i");
list.add("j");
list.add("k");
list.add("l");
list.add("m");
PageModel pm = new PageModel(list, 8);//每页显示条数 List sublist = pm.getObjects(2);//显示第几页
for (int i = 0; i < sublist.size(); i++) {
System.out.println(sublist.get(i));
}
}
}
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