Java tutorial
package com.logisticsShop.utils; /** * Copyright 2010 Fuchun. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.lang.reflect.Type; import java.util.Collection; import java.util.Enumeration; import java.util.Iterator; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.reflect.TypeToken; /** * ?? {@code JSON} ?? * <p /> * ?{@code JSON} ??<a href="http://code.google.com/p/google-gson/" * mce_href="http://code.google.com/p/google-gson/" target="_blank"> {@code Google Gson}</a>? * ? * * <pre> * public class User { * @SerializedName("pwd") * private String password; * @Expose * @SerializedName("uname") * private String username; * @Expose * @Since(1.1) * private String gender; * @Expose * @Since(1.0) * private String sex; * * public User() {} * public User(String username, String password, String gender) { * // user constructor code... ... ... * } * * public String getUsername() * ... ... ... * } * List<User> userList = new LinkedList<User>(); * User jack = new User("Jack", "123456", "Male"); * User marry = new User("Marry", "888888", "Female"); * userList.add(jack); * userList.add(marry); * Type targetType = new TypeToken<List<User>>(){}.getType(); * String sUserList1 = JSONUtils.toJson(userList, targetType); * sUserList1 ----> [{"uname":"jack","gender":"Male","sex":"Male"},{"uname":"marry","gender":"Female","sex":"Female"}] * String sUserList2 = JSONUtils.toJson(userList, targetType, false); * sUserList2 ----> [{"uname":"jack","pwd":"123456","gender":"Male","sex":"Male"},{"uname":"marry","pwd":"888888","gender":"Female","sex":"Female"}] * String sUserList3 = JSONUtils.toJson(userList, targetType, 1.0d, true); * sUserList3 ----> [{"uname":"jack","sex":"Male"},{"uname":"marry","sex":"Female"}] * </pre> * * @author Fuchun * @since ay-commons-lang 1.0 * @version 1.1.0 */ public class JsonUtil { /** {@code JSON} ? - <code>"{}"</code>?*/ public static final String EMPTY_JSON = "{}"; /** {@code JSON} (?)? - {@code "[]"}?*/ public static final String EMPTY_JSON_ARRAY = "[]"; /** ?{@code JSON} /???*/ public static final String DEFAULT_DATE_PATTERN = "yyyy-MM-dd HH:mm:ss SSS"; /** {@code Google Gson} ?<code>@Since</code> ?? - {@code 1.0}?*/ public static final double SINCE_VERSION_10 = 1.0d; /** {@code Google Gson} ?<code>@Since</code> ?? - {@code 1.1}?*/ public static final double SINCE_VERSION_11 = 1.1d; /** {@code Google Gson} ?<code>@Since</code> ?? - {@code 1.2}?*/ public static final double SINCE_VERSION_12 = 1.2d; /** {@code Google Gson} ?<code>@Until</code> ?? - {@code 1.0}?*/ public static final double UNTIL_VERSION_10 = SINCE_VERSION_10; /** {@code Google Gson} ?<code>@Until</code> ?? - {@code 1.1}?*/ public static final double UNTIL_VERSION_11 = SINCE_VERSION_11; /** {@code Google Gson} ?<code>@Until</code> ?? - {@code 1.2}?*/ public static final double UNTIL_VERSION_12 = SINCE_VERSION_12; /** * <p> * <code>JSONUtils</code> instances should NOT be constructed in standard programming. Instead, * the class should be used as <code>JSONUtils.fromJson("foo");</code>. * </p> * <p> * This constructor is public to permit tools that require a JavaBean instance to operate. * </p> */ public JsonUtil() { super(); } /** * ????? {@code JSON} ?? * <p /> * <b>??????<code>"{}"</code>???<code>"[]"</code> </b> * * @param target * ? * @param targetType * ? * @param isSerializeNulls * ???{@code null} ? * @param version * ?? * @param datePattern * ??? * @param excludesFieldsWithoutExpose * ??{@literal @Expose} ? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, Type targetType, boolean isSerializeNulls, Double version, String datePattern, boolean excludesFieldsWithoutExpose) { if (target == null) return EMPTY_JSON; GsonBuilder builder = new GsonBuilder(); if (isSerializeNulls) builder.serializeNulls(); if (version != null) builder.setVersion(version.doubleValue()); builder.setDateFormat(datePattern); if (excludesFieldsWithoutExpose) builder.excludeFieldsWithoutExposeAnnotation(); return toJson(target, targetType, builder); } /** * ??{@code JSON} ??b>?????{@code JavaBean} ?/b> * <ul> * <li>???{@literal @Expose} </li> * <li>??{@code null} </li> * <li>???{@literal @Since} </li> * <li>??/ ??- {@code yyyy-MM-dd HH:mm:ss SSS}?/li> * </ul> * * @param target * ??? {@code JSON} ? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target) { return toJson(target, null, false, null, null, true); } /** * ??{@code JSON} ??b>?????{@code JavaBean} ?/b> * <ul> * <li>???{@literal @Expose} </li> * <li>??{@code null} </li> * <li>???{@literal @Since} </li> * </ul> * * @param target * ??? {@code JSON} ? * @param datePattern * ??? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, String datePattern) { return toJson(target, null, false, null, datePattern, true); } /** * ??{@code JSON} ??b>?????{@code JavaBean} ?/b> * <ul> * <li>???{@literal @Expose} </li> * <li>??{@code null} </li> * <li>??/ ??- {@code yyyy-MM-dd HH:mm:ss SSS}?/li> * </ul> * * @param target * ??? {@code JSON} ? * @param version * ?({@literal @Since})? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, Double version) { return toJson(target, null, false, version, null, true); } /** * ??{@code JSON} ??b>?????{@code JavaBean} ?/b> * <ul> * <li>??{@code null} </li> * <li>???{@literal @Since} </li> * <li>??/ ??- {@code yyyy-MM-dd HH:mm:ss SSS}?/li> * </ul> * * @param target * ??? {@code JSON} ? * @param excludesFieldsWithoutExpose * ??{@literal @Expose} ? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, boolean excludesFieldsWithoutExpose) { return toJson(target, null, false, null, null, excludesFieldsWithoutExpose); } /** * ??{@code JSON} ??b>?????{@code JavaBean} ?/b> * <ul> * <li>??{@code null} </li> * <li>??/ ??- {@code yyyy-MM-dd HH:mm:ss SSS}?/li> * </ul> * * @param target * ??? {@code JSON} ? * @param version * ?({@literal @Since})? * @param excludesFieldsWithoutExpose * ??{@literal @Expose} ? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, Double version, boolean excludesFieldsWithoutExpose) { return toJson(target, null, false, version, null, excludesFieldsWithoutExpose); } /** * ??{@code JSON} ??b>????/b> * <ul> * <li>???{@literal @Expose} </li> * <li>??{@code null} </li> * <li>???{@literal @Since} </li> * <li>??/ ??- {@code yyyy-MM-dd HH:mm:ss SSSS}?/li> * </ul> * * @param target * ??? {@code JSON} ? * @param targetType * ? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, Type targetType) { return toJson(target, targetType, false, null, null, true); } /** * ??{@code JSON} ??b>????/b> * <ul> * <li>???{@literal @Expose} </li> * <li>??{@code null} </li> * <li>??/ ??- {@code yyyy-MM-dd HH:mm:ss SSSS}?/li> * </ul> * * @param target * ??? {@code JSON} ? * @param targetType * ? * @param version * ?({@literal @Since})? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, Type targetType, Double version) { return toJson(target, targetType, false, version, null, true); } /** * ??{@code JSON} ??b>????/b> * <ul> * <li>??{@code null} </li> * <li>???{@literal @Since} </li> * <li>??/ ??- {@code yyyy-MM-dd HH:mm:ss SSS}?/li> * </ul> * * @param target * ??? {@code JSON} ? * @param targetType * ? * @param excludesFieldsWithoutExpose * ??{@literal @Expose} ? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, Type targetType, boolean excludesFieldsWithoutExpose) { return toJson(target, targetType, false, null, null, excludesFieldsWithoutExpose); } /** * ??{@code JSON} ??b>????/b> * <ul> * <li>??{@code null} </li> * <li>??/ ??- {@code yyyy-MM-dd HH:mm:ss SSS}?/li> * </ul> * * @param target * ??? {@code JSON} ? * @param targetType * ? * @param version * ?({@literal @Since})? * @param excludesFieldsWithoutExpose * ??{@literal @Expose} ? * @return ?{@code JSON} ?? * @since 1.0 */ public static String toJson(Object target, Type targetType, Double version, boolean excludesFieldsWithoutExpose) { return toJson(target, targetType, false, version, null, excludesFieldsWithoutExpose); } /** * {@code JSON} ??? * * @param <T> * ??? * @param json * ?{@code JSON} ? * @param token * {@code com.google.gson.reflect.TypeToken} ? * @param datePattern * ??? * @return ?{@code JSON} ? * @since 1.0 */ public static <T> T fromJson(String json, TypeToken<T> token, String datePattern) { GsonBuilder builder = new GsonBuilder(); Gson gson = builder.create(); try { return gson.fromJson(json, token.getType()); } catch (Exception ex) { return null; } } /** * {@code JSON} ??? * * @param <T> * ??? * @param json * ?{@code JSON} ? * @param token * {@code com.google.gson.reflect.TypeToken} ? * @return ?{@code JSON} ? * @since 1.0 */ public static <T> T fromJson(String json, TypeToken<T> token) { return fromJson(json, token, null); } /** * {@code JSON} ???<b>??? {@code JavaBean} ?/b> * * @param <T> * ??? * @param json * ?{@code JSON} ? * @param clazz * ??? * @param datePattern * ??? * @return ?{@code JSON} ? * @since 1.0 */ public static <T> T fromJson(String json, Class<T> clazz, String datePattern) { GsonBuilder builder = new GsonBuilder(); Gson gson = builder.create(); try { return gson.fromJson(json, clazz); } catch (Exception ex) { return null; } } /** * {@code JSON} ???<b>??? {@code JavaBean} ?/b> * * @param <T> * ??? * @param json * ?{@code JSON} ? * @param clazz * ??? * @return ?{@code JSON} ? * @since 1.0 */ public static <T> T fromJson(String json, Class<T> clazz) { return fromJson(json, clazz, null); } /** * ?{@code GsonBuilder} ?????{@code JSON} ?? * <p /> * ?????{@code JavaBean} <code>"{}"</code>??? * <code>"[]"</code>?? * * @param target * ? * @param targetType * ? * @param builder * ?{@code Gson} ? * @return ?{@code JSON} ?? * @since 1.1 */ public static String toJson(Object target, Type targetType, GsonBuilder builder) { if (target == null) return EMPTY_JSON; Gson gson = null; if (builder == null) { gson = new Gson(); } else { gson = builder.create(); } String result = EMPTY_JSON; try { if (targetType == null) { result = gson.toJson(target); } else { result = gson.toJson(target, targetType); } } catch (Exception ex) { if (target instanceof Collection<?> || target instanceof Iterator<?> || target instanceof Enumeration<?> || target.getClass().isArray()) { result = EMPTY_JSON_ARRAY; } } return result; } }