查询条件拼凑SQL

public static void query() throws ParseException {		String jsonStr = "{applyNo:{like:'A001'}, name:{=:'张三'}, amt:{>: 600, oper: 'or', <: 1000}}";		JSONObject json = new JSONObject(jsonStr);		Iterator<String> iter = json.keys();		StringBuffer jpql = new StringBuffer("select * from table");		// 放置参数		List<Object> params = new ArrayList<Object>();		int index = 0;				boolean firstFlag = true;		while (iter.hasNext()) {			// 查询字段			String key = iter.next();			JSONObject obj = json.getJSONObject(key);			if (firstFlag) {				firstFlag = false;				jpql.append(" where ");			} else {				jpql.append(" and ");			}			jpql.append(key).append(" ");			Iterator<String> valIter = obj.keys();			while (valIter.hasNext()) {				// 查询条件				String valKey = valIter.next();				// 不是操作符，就执行				if (!"oper".equals(valKey)) {					Object valObj = obj.get(valKey);					jpql.append(valKey).append(" ?_").append(index).append(" ");					if (valIter.hasNext()) {						Object oper = obj.get("oper");						jpql.append(" ").append(oper).append(" ");					}										params.add(valObj);					index++;				}			}		}		System.out.println(jpql);		System.out.println(Arrays.toString(params.toArray()));	}