遍历List中得到的结果并添加逗号(为了 拼接sql)

 

public static String whererIn(String fieldName,List listGroupIds) {

String sqlWhere=" ";

StringBuffer sb = new StringBuffer();

if(!listGroupIds.equals("")&& listGroupIds!=null){

for(int i=0;i

sb.append("'" + listGroupIds.get(i) + "'");

if(i != listGroupIds.size() -1){

sb.append(",");

}

}

sqlWhere+=" and "+fieldName+" in ("+sb.toString()+")";

}

return sqlWhere;

}

2:利用For Each循环的写法：

 

 

public static String whererIn2(String fieldName, List listGroupIds){

String whatYouNeedGroupId = "";

for(String id : listGroupIds){

whatYouNeedGroupId += "'" + id + "'" + ",";

}

whatYouNeedGroupId = whatYouNeedGroupId.substring(0, whatYouNeedGroupId.length()-1);

String sqlWhere=" and "+fieldName+" in ("+whatYouNeedGroupId.toString()+")";

return sqlWhere;

}

最后写一个main函数测试：

public static void main(String[] args) {

List list=new ArrayList();

list.add("cyz");

list.add("zwb");

System.out.println(whererIn("s.groupId",list));

System.out.println(whererIn2("s.groupId",list));