直接上工具类代码
package com.xxx.util;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.List;
public class ListUtils {
public static <T> List<List<T>> partition(final List<T> list, final int size) {
if (list == null) {
throw new NullPointerException("List must not be null");
}
if (size <= 0) {
throw new IllegalArgumentException("Size must be greater than 0");
}
return new Partition<>(list, size);
}
private static class Partition<T> extends AbstractList<List<T>> {
private final List<T> list;
private final int size;
private Partition(final List<T> list, final int size) {
this.list = list;
this.size = size;
}
@Override
public List<T> get(final int index) {
final int listSize = size();
if (index < 0) {
throw new IndexOutOfBoundsException("Index " + index + " must not be negative");
}
if (index >= listSize) {
throw new IndexOutOfBoundsException("Index " + index + " must be less than size " +
listSize);
}
final int start = index * size;
final int end = Math.min(start + size, list.size());
return list.subList(start, end);
}
@Override
public int size() {
return (int) Math.ceil((double) list.size() / (double) size);
}
@Override
public boolean isEmpty() {
return list.isEmpty();
}
}
public static void main(String[] args) {
List<String> list=new ArrayList<String>();
for (int i = 0; i <= 1000000; i++) {
list.add(i+"");
}
//将list集合按照2000条数据分割为一个单独的List集合
List<List<String>> partition = ListUtils.partition(list, 2000);
System.out.println(partition.size());
}
}