怎么从json字符串中截取字符串

这样的话，只需要截取需要的字符串即可。
举例：
public static void main(String[] args) {
String parse="[{CSTM_NO:\"11118\",CSTM_NAME:\"广东XX电力有限公司\",FIX_GNL:\"111810158\",FIX_ACC:\"D201306070003\",OP_FLAG:\"正常\",BUSS_KIND_NAME:\"三个月定期存款\",BAL:\"25,178,750.00\",AVAL_BAL:\"25,178,750.00\",OP_DATE:\"2013-06-07\",DUE_DATE:\"2013-12-07\",ROWNUM_:1,idx:0},{CSTM_NO:\"11118\",CSTM_NAME:\"广东XX电力有限公司\",FIX_GNL:\"111810158\",FIX_ACC:\"D201306070002\",OP_FLAG:\"正常\",BUSS_KIND_NAME:\"三个月定期存款\",BAL:\"25,178,750.00\",AVAL_BAL:\"25,178,750.00\",OP_DATE:\"2013-06-07\",DUE_DATE:\"2013-12-07\",ROWNUM_:3,idx:2},{CSTM_NO:\"11118\",CSTM_NAME:\"广东XX电力有限公司\",FIX_GNL:\"111810158\",FIX_ACC:\"D201306070005\",OP_FLAG:\"正常\",BUSS_KIND_NAME:\"三个月定期存款\",BAL:\"25,178,750.00\",AVAL_BAL:\"25,178,750.00\",OP_DATE:\"2013-06-07\",DUE_DATE:\"2013-12-07\",ROWNUM_:4,idx:3}]";
String regex="FIX_ACC:(.*?),OP_FLAG";//别忘了使用非贪婪模式！
Matcher matcher=Pattern.compile(regex).matcher(parse);
while(matcher.find())
{
String ret=matcher.group(1);
System.out.println(ret);
}
}