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));
}
}
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