java遞歸實例（二）---遞歸讀取並修改Tree結構

public class RecursionTest {
	
	public String updateCategrotyRel(Integer idMerchant)
		throws Exception{
		String str = "[{\"idOpeCate\":1,\"name\":\"手機\",\"parentId\":0,"
				+ "\"children\":[{\"idOpeCate\":2,\"name\":\"蘋果\",\"parentId\":1},"
				+ "{\"idOpeCate\":3,\"name\":\"小米\",\"parentId\":1}]},"
				+ "{\"idOpeCate\":4,\"name\":\"電腦\",\"parentId\":0}]";
		//根據idMerchant獲取表中已經勾選的ID
		List<Integer> checkedIds = xxService.getCheckedIds(idMerchant);
		str = this.SetCatChecked(str,checkedIds);
		return str;
	}

	private String SetCatChecked(String str, List<Integer> checkedIds) 
			throws JsonParseException, JsonMappingException, IOException {
		List<Map> strList = JsonUtil.jsonToObjectList(str, Map.class);
		recursionOpeCate(checkedIds,strList);
		str = JsonUtil.objectListToString(strList);
		return str;
	}

	//遞歸設置是否選中
	private void recursionOpeCate(List<Integer> checkedIds, List<Map> strList) {
		for(int i = 0;i < (strList != null && strList.size() > 0 
				? strList.size() : 0);i++){
			if(strList.get(i).get("children") != null){
				this.recursionOpeCate(checkedIds, (List<Map>)strList.get(i).get("children"));
			}
			for(int j = 0;j < (checkedIds != null && checkedIds.size() > 0 
					? checkedIds.size() : 0);j++){
				if(((Integer)strList.get(i).get("id")).intValue() == 
						(Integer)checkedIds.get(j).intValue()){
					strList.get(i).put("checked",true);
				}
			}
		}
	}

}