java解析任意层数json字符串的方法
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2022-05-05 19:53:48
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一个方法解析任意层数的json字符窜:使用正则表达式,递归算法,将jsonArray解析出后添加到List, JsonObject添加至Map
//解析策略,有可能是解析json字符串,有可能为数据中的图片地址,email等 package cc.util.regex; public enum RegexPolicy { Json("Json"), Image("ImageFromHtml"); private String value; RegexPolicy (String value) { this.value = value; } @Override public String toString() { // TODO Auto-generated method stub return value; } } package cc.util.regex; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import android.util.Log; /** * A static Class help to Analyze data * @author wangcccong * @version 1.140122 * create at: 14-02-14 */ public class RegexUtil { //与解析策略相匹配的正则表达式 //private static final String REGULAR_IMG_HTML = "<img +?src=\"(.+?)\""; private static final String REGULAR_JSON_ITEM_NAME = "\"([^\\\" ]+?)\":"; //private static final String REGULAR_JSON_ARRAY_NAME = ", *?\" *?([a-zA-Z0-9]*?) *?\" *?: *?\\[ *?\\{"; //公用方法解析,将字符串传入即可 public static Object regex(final RegexPolicy policy, final String data) { switch (policy) { case Json: return regexJson(data); case Image: break; default: break; } return null; } /** * By recursively parse the Json string, obtain the Json string name by the regular expression, * see also Matcher and Pattern and analysis of data. If the analytical data JsonObject object return key value pair (Map), * if JsonArray List is returned, otherwise it returns String. * <br><b>Notice:</b> if return Map you should better invoke map.get(null) to obtain value. * @see {@link java.util.regex.Matcher}, {@link java.util.regex.Pattern} * @param jsonStr * @return {@link java.util.Map} or {@link java.util.List} or {@link java.lang.String} */ private static Object regexJson(final String jsonStr) { if (jsonStr == null) throw new NullPointerException("JsonString shouldn't be null"); try { if (isJsonObject(jsonStr)) { final Pattern pattern = Pattern.compile(REGULAR_JSON_ITEM_NAME); final Matcher matcher = pattern.matcher(jsonStr); final Map<String, Object> map = new HashMap<String, Object>(); final JSONObject jsonObject = new JSONObject(jsonStr); for ( ; matcher.find(); ) { String groupName = matcher.group(1); Object obj = jsonObject.opt(groupName); if (obj != null && isJsonArray(obj.toString())) matcher.region(matcher.end() + obj.toString().replace("\\", "").length(), matcher.regionEnd()); if (obj != null && !map.containsKey(groupName)) map.put(groupName, regexJson(obj.toString())); } return map; } else if (isJsonArray(jsonStr)) { List<Object> list = new ArrayList<Object>(); JSONArray jsonArray = new JSONArray(jsonStr); for (int i = 0; i < jsonArray.length(); i++) { Object object = jsonArray.opt(i); list.add(regexJson(object.toString())); } return list; } } catch (Exception e) { // TODO: handle exception Log.e("RegexUtil--regexJson", e.getMessage()+""); } return jsonStr; } /** * To determine whether a string is JsonObject {@link org.json.JSONObject} * @param jsonStr {@link java.lang.String} * @return boolean */ private static boolean isJsonObject(final String jsonStr) { if (jsonStr == null) return false; try { new JSONObject(jsonStr); return true; } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); return false; } } /** * To determine whether a string is JsonArray {@link org.json.JSONArray}; * @param jsonStr {@link java.lang.String} * @return boolean */ private static boolean isJsonArray(final String jsonStr) { if (jsonStr == null) return false; try { new JSONArray(jsonStr); return true; } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); return false; } } } //使用方法 Object object = RegexUtil.regex(RegexPolicy.Json, jsonStr.substring(jsonStr.indexOf("{"), jsonStr.lastIndexOf("}")+1)); if (object instanceof String) { Log.e("string", object.toString()); } else if (object instanceof Map) { @SuppressWarnings("unchecked") HashMap<String, Object> map = (HashMap<String, Object>)object; Iterator<Entry<String, Object>> iterator = map.entrySet().iterator(); while (iterator.hasNext()) { Entry<String, Object> entry = iterator.next(); if (entry.getValue() instanceof List) { Log.e(entry.getKey(), entry.getValue().toString()); } else { Log.e(entry.getKey(), entry.getValue().toString()); } } } else if (object instanceof List) { Log.e("list", object.toString()); }
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