按批次处理list数据的两种方法
主要应用于list存储数据过多，不能使list整体进行其余操作
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package net.xsoftlab.na;
import java.util.ArrayList;
import java.util.List;
/** * 按批次处理list数据的两种方法
* 主要应用于list存储数据过多，不能使list整体进行其余操作
* @author zhouhongna
* @date 2014-10-20
*
*/
public class DealListByBatch {
/**
* 通过list的 subList(int fromIndex, int toIndex)方法实现
* @param sourList 源list
* @param batchCount 分组条数
*/
public static void dealBySubList(List<Object> sourList, int batchCount){
int sourListSize = sourList.size();
int subCount = sourListSize%batchCount==0 ? sourListSize/batchCount : sourListSize/batchCount+1;
int startIndext = 0;
int stopIndext = 0;
for(int i=0;i<subCount;i++){
stopIndext = (i==subCount-1) ? stopIndext + sourListSize%batchCount : stopIndext + batchCount;
List<Object> tempList = new ArrayList<Object>(sourList.subList(startIndext, stopIndext));
printList(tempList);
startIndext = stopIndext;
}
}
/**
* 通过源list数据的逐条转移实现
* @param sourList 源list
* @param batchCount 分组条数
*/
public static void dealByRemove(List<Object> sourList, int batchCount){
List<Object> tempList = new ArrayList<Object>();
for (int i = 0; i < sourList.size(); i++) {
tempList.add(sourList.get(i));
if((i+1)%batchCount==0 || (i+1)==sourList.size()){
printList(tempList);
tempList.clear();
}
}
}
/**
* 打印方法 充当list每批次数据的处理方法
* @param sourList
*/
public static void printList(List<Object> sourList){
for(int j=0;j<sourList.size();j++){
System.out.println(sourList.get(j));
}
System.out.println("------------------------");
}
/**
* 测试主方法
* @param args
*/
public static void main(String[] args) {
List<Object> list = new ArrayList<Object>();
for (int i = 0; i < 91; i++) {
list.add(i);
}
long start = System.nanoTime();
dealBySubList(list, 10);
dealByRemove(list, 10);
long end = System.nanoTime();
System.out.println("The elapsed time :" + (end-start));
}
} |