JAVA List集合转Page(分页对象)

时间:2023-03-10 08:02:08
JAVA List集合转Page(分页对象)
/**
* @version 1.0
* @author: fwjia
*/
import java.util.List; public class PageModel<T> {
/***
* 当前页
*/
private int page = 1; /***
* 总页数
*/
public int totalPages = 0; /***
* 每页数据条数
*/
private int pageRecorders; /***
* 总页数
*/
private int totalRows = 0; /***
* 每页的起始数
*/
private int pageStartRow = 0; /***
* 每页显示数据的终止数
*/
private int pageEndRow = 0; /***
* 是否有下一页
*/
private boolean hasNextPage = false; /***
* 是否有前一页
*/
private boolean hasPreviousPage = false; /***
* 数据集合
*/
private List<T> list; public PageModel(List<T> list, int pageRecorders) {
// 通过对象集,记录总数划分
init(list, pageRecorders);
} /** *//**
* 初始化list,并告之该list每页的记录数
* @param list 数据几个
* @param pageRecorders 一页显示多少数据
*/
public void init(List<T> list, int pageRecorders) {
this.pageRecorders = pageRecorders;
this.list = list;
totalRows = list.size();
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 当前页面
* @return
*/
public List<T> 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<T> objects = null;
if (!list.isEmpty()) {
objects = list.subList(pageStartRow, pageEndRow);
}
//this.description();
return objects;
} public List<T> 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;
} }

  测试类TestPagerModel

import java.util.ArrayList;
import java.util.List; /**
* @version 1.0
* @author: fwjia
*/
public class TestPagerModel { 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<String> pm = new PageModel(list, 5); List<String> sublist = pm.getObjects(2);
for(int i = 0; i < sublist.size(); i++) {
System.out.println(sublist.get(i));
}
} }