根据start和limit从已有的数据列表中获取从start开始的limit个数据

package com.zhipengs.work.test;import java.io.Serializable;/**
* 实体类Store
*
* @author zhipengs
*/
public class Store implements Serializable {
private static final long serialVersionUID = 8799004943860173845L;
private Long storeId;
private String storeName;
private String longitude;
private String latitude;
private String storeLogo; public Store(Long storeId, String storeName, String longitude,
String latitude, String storeLogo) {
super();
this.storeId = storeId;
this.storeName = storeName;
this.longitude = longitude;
this.latitude = latitude;
this.storeLogo = storeLogo;
} public Long getStoreId() {
return storeId;
} public void setStoreId(Long storeId) {
this.storeId = storeId;
} public String getStoreName() {
return storeName;
} public void setStoreName(String storeName) {
this.storeName = storeName;
} public String getLongitude() {
return longitude;
} public void setLongitude(String longitude) {
this.longitude = longitude;
} public String getLatitude() {
return latitude;
} public void setLatitude(String latitude) {
this.latitude = latitude;
} public String getStoreLogo() {
return storeLogo;
} public void setStoreLogo(String storeLogo) {
this.storeLogo = storeLogo;
} @Override
public String toString() {
return "Store [storeId=" + storeId + ", storeName=" + storeName
+ ", longitude=" + longitude + ", latitude=" + latitude
+ ", storeLogo=" + storeLogo + "]";
}}

package com.zhipengs.work.test;import java.util.ArrayList;
import java.util.List;
/**
* 写成工具类DataStartLimitUtil
*
* @author zhipengs
*/
public class DataStartLimitUtil { public static List<Object> getLimitSampleStores(Integer start,
Integer limit, List<Object> data) {
System.out.println("start=" + start + " limit=" + limit);
List<Object> dataReturn = new ArrayList<Object>();
// 如果data为null，直接返回或者获取数据的起始位置大于等于data的大小则返回null
if (null == data || data.size() <= start) {
return null;
}
// 计算需要取data数据的最后一个位置loop，start为起始位置，共取limit个
int loop = start + limit;
// 如果data的大小大于等于获取数据的其实位置的同时又小于需要取得data数据的最后一个位置数loop，则将loop重置为data的大小
if (data.size() >= start && data.size() < loop) {
loop = data.size();
}
// 循环遍历获取data中第start个位置到第loop个位置的数据，放入新的列表中并返回
for (int i = start; i < loop; i++) {
dataReturn.add(data.get(i));
}
return dataReturn;
}
}

package com.zhipengs.work.test;import java.util.ArrayList;
import java.util.List;
import java.util.Random;
/**
* 测试
*
* @author zhipengs
*/
public class MainTest {
@SuppressWarnings("unused")
public static void main(String[] args) {
List<Object> storeRerurnList = null;
List<Object> storeList = null;
Store store = null; // storeList为null
storeRerurnList = DataStartLimitUtil.getLimitSampleStores(0, 21, storeList);
System.out.println("storeList为null，返回的数据列表："+storeRerurnList);
System.out.println("------------------------------------------------------"); // 往storeList中存入20条数据
storeList = new ArrayList<Object>();
for (int i = 0; i < 20; i++) {
store = new Store((long) i+1, "_store_", "113.85786457474","23.7635746576", "mobile/"
+ Math.abs(new Random().nextInt()) + ".jpg");
storeList.add(store);
} // 获取数据的起始位置大于等于storeList的size
storeRerurnList = DataStartLimitUtil.getLimitSampleStores(20, 1, storeList);
System.out.println("获取数据的起始位置大于等于storeList的size，返回的数据列表："+storeRerurnList);
System.out.println("------------------------------------------------------"); // storeList的size大于等于获取数据的起始位置的同时又小于需要取得data数据的最后一个位置数
storeRerurnList = DataStartLimitUtil.getLimitSampleStores(0, 25, storeList);
System.out.println("storeList有20条数据，从0取25条，storeRerurnList.size(): " + storeRerurnList.size());
System.out.println("storeList有20条数据，从0取25条，第一条"+storeRerurnList.get(0));
System.out.println("------------------------------------------------------"); storeRerurnList = DataStartLimitUtil.getLimitSampleStores(5, 25, storeList);
System.out.println("storeList有20条数据，从5取25条，storeRerurnList.size(): " + storeRerurnList.size());
System.out.println("storeList有20条数据，从5取25条，第一条"+storeRerurnList.get(0)); // 正常获取数据
System.out.println("---------------------循环获取所有数据---------------------");
for(int i=0;i<25;i+=5) {
storeRerurnList = DataStartLimitUtil.getLimitSampleStores(i, 5, storeList);
if(null == storeRerurnList) {
System.out.println(storeRerurnList);
} else {
System.out.println("storeList有20条数据，从"+i+"取5条，storeRerurnList.size(): " + storeRerurnList.size());
System.out.println("storeList有20条数据，从"+i+"取5条，第一条"+storeRerurnList.get(0));
System.out.println("------------------------------------------------------");
} } /*
* for(Object o : storeRerurnList) { if(o instanceof Store) {
* System.out.println((Store)o); } }
*/ }
}