hibernate(一对多，多对一映射)操作

/* * Delta CONFIDENTIAL * * (C) Copyright Delta Electronics, Inc. 2015 All Rights Reserved * * NOTICE: All information contained herein is, and remains the * property of Delta Electronics. The intellectual and technical * concepts contained herein are proprietary to Delta Electronics * and are protected by trade secret, patent law or copyright law. * Dissemination of this information or reproduction of this material * is strictly forbidden unless prior written permission is obtained * from Delta Electronics. */ package com.shuyu.utils; import java.util.ArrayList; import java.util.List; import java.util.Map; import com.google.gson.Gson; import com.google.gson.JsonArray; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonParser; import com.google.gson.JsonSyntaxException; import com.google.gson.reflect.TypeToken; public class GsonUtil { private static Gson gson = null; static { if (gson == null) { gson = new Gson(); } } private GsonUtil() { } /** * Object to json * * @param object * @return */ public static String GsonString(Object object) { String gsonString = null; if (gson != null) { gsonString = gson.toJson(object); } return gsonString; } /** * json to bean * * @param gsonString * @param cls * @return */ public static <T> T GsonToBean(String gsonString, Class<T> cls) throws JsonSyntaxException { T t = null; if (gson != null && gsonString != null && !gsonString.equals("")) { t = gson.fromJson(gsonString, cls); } return t; } /** * json to list * * @param gsonString * @param cls * @return */ public static <T> List<T> GsonToList(String gsonString, Class<T> cls) throws JsonSyntaxException { List<T> list = new ArrayList<T>(); if (gson != null && gsonString != null && !gsonString.equals("")) { JsonArray array = new JsonParser().parse(gsonString).getAsJsonArray(); for (final JsonElement elem : array) { list.add(gson.fromJson(elem, cls)); } } return list; } /** * json to list * * @param gsonString * @return */ public static <T> List<Map<String, T>> GsonToListMaps(String gsonString) { List<Map<String, T>> list = null; if (gson != null) { list = gson.fromJson(gsonString, new TypeToken<List<Map<String, T>>>() { }.getType()); } return list; } /** * json to Map * * @param gsonString * @return */ public static <T> Map<String, T> GsonToMaps(String gsonString) { Map<String, T> map = null; if (gson != null) { map = gson.fromJson(gsonString, new TypeToken<Map<String, T>>() { }.getType()); } return map; } /** * Object to JsonObject * * @param object * @return */ public static JsonObject GetJsonObject(Object object) { JsonObject jsonObject = null; if (gson != null) { jsonObject = gson.toJsonTree(object).getAsJsonObject(); } return jsonObject; } public static String GetValue(String json, String key) throws Exception { JsonObject jsonObject = null; if (gson != null) { jsonObject = new JsonParser().parse(json).getAsJsonObject(); } if (jsonObject != null && jsonObject.has(key)) { return jsonObject.get(key).getAsString(); } return null; } public static JsonObject parse(String param) throws JsonSyntaxException { JsonParser parser = new JsonParser(); JsonElement jsonElement = parser.parse(param); JsonObject data = jsonElement.getAsJsonObject(); return data; } }