download:Java 工程师高薪训练营
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public class ListPageUtil<T> {
/**
* 每页显示条数
*/
private int pageSize;
/**
* 总页数
*/
private int pageCount;
/**
* 原汇合
*/
private List<T> data;
public ListPageUtil(List<T> data, int pageSize) {if (data == null || data.isEmpty()) {throw new IllegalArgumentException("data must be not empty!");
}
this.data = data;
this.pageSize = pageSize;
this.pageCount = data.size()/pageSize;
if(data.size()%pageSize!=0){this.pageCount++;}
}
/**
* 失去分页后的数据
*
* @param pageNum 页码
* @return 分页后后果
*/
public List<T> getPagedList(int pageNum) {int fromIndex = (pageNum - 1) * pageSize;
if (fromIndex >= data.size()) {return Collections.emptyList();
}
int toIndex = pageNum * pageSize;
if (toIndex >= data.size()) {toIndex = data.size();
}
return data.subList(fromIndex, toIndex);
}
public int getPageSize() {return pageSize;}
public List<T> getData() {return data;}
public int getPageCount() {return pageCount;}
public static void main(String[] args) {Integer[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
List<Integer> list = Arrays.asList(array);
ListPageUtil<Integer> pager = new ListPageUtil<Integer>(list, 10);
System.out.println(pager.getPageCount());
List<Integer> page1 = pager.getPagedList(1);
System.out.println(page1);
List<Integer> page2 = pager.getPagedList(2);
System.out.println(page2);
List<Integer> page3 = pager.getPagedList(3);
System.out.println(page3);
}
}