在一样平常的Android开发当中，我们肯定少不了要利用Gson框架分析JSON字符串。这篇博客分享一下我相识到Gson框架的知识，渴望对看文章的小搭档有所资助。
Gson的依赖
implementation 'com.google.code.gson:gson:2.9.0'
这里必要注意的是：
Gson2.9.0最低适配Java7，假如想要是用Java6及其以下的版本要利用Gson2.8.9。
利用Gson开发的时间，我保举一个工具类：
package com.blankj.utilcode.util;import android.text.TextUtils;import com.google.gson.Gson;import com.google.gson.GsonBuilder;import com.google.gson.reflect.TypeToken;import java.io.Reader;import java.lang.reflect.Type;import java.util.List;import java.util.Map;import java.util.Set;import java.util.concurrent.ConcurrentHashMap;import androidx.annotation.NonNull;/** * <pre> * author: Blankj * blog : http://blankj.com * time : 2018/04/05 * desc : utils about gson * </pre> */public final class GsonUtils { private static final String KEY_DEFAULT = "defaultGson"; private static final String KEY_DELEGATE = "delegateGson"; private static final String KEY_LOG_UTILS = "logUtilsGson"; private static final Map<String, Gson> GSONS = new ConcurrentHashMap<>(); private GsonUtils() { throw new UnsupportedOperationException("u can't instantiate me..."); } /** * Set the delegate of {@link Gson}. * * @param delegate The delegate of {@link Gson}. */ public static void setGsonDelegate(Gson delegate) { if (delegate == null) return; GSONS.put(KEY_DELEGATE, delegate); } /** * Set the {@link Gson} with key. * * @param key The key. * @param gson The {@link Gson}. */ public static void setGson(final String key, final Gson gson) { if (TextUtils.isEmpty(key) || gson == null) return; GSONS.put(key, gson); } /** * Return the {@link Gson} with key. * * @param key The key. * @return the {@link Gson} with key */ public static Gson getGson(final String key) { return GSONS.get(key); } public static Gson getGson() { Gson gsonDelegate = GSONS.get(KEY_DELEGATE); if (gsonDelegate != null) { return gsonDelegate; } Gson gsonDefault = GSONS.get(KEY_DEFAULT); if (gsonDefault == null) { gsonDefault = createGson(); GSONS.put(KEY_DEFAULT, gsonDefault); } return gsonDefault; } /** * Serializes an object into json. * * @param object The object to serialize. * @return object serialized into json. */ public static String toJson(final Object object) { return toJson(getGson(), object); } /** * Serializes an object into json. * * @param src The object to serialize. * @param typeOfSrc The specific genericized type of src. * @return object serialized into json. */ public static String toJson(final Object src, @NonNull final Type typeOfSrc) { return toJson(getGson(), src, typeOfSrc); } /** * Serializes an object into json. * * @param gson The gson. * @param object The object to serialize. * @return object serialized into json. */ public static String toJson(@NonNull final Gson gson, final Object object) { return gson.toJson(object); } /** * Serializes an object into json. * * @param gson The gson. * @param src The object to serialize. * @param typeOfSrc The specific genericized type of src. * @return object serialized into json. */ public static String toJson(@NonNull final Gson gson, final Object src, @NonNull final Type typeOfSrc) { return gson.toJson(src, typeOfSrc); } /** * Converts {@link String} to given type. * * @param json The json to convert. * @param type Type json will be converted to. * @return instance of type */ public static <T> T fromJson(final String json, @NonNull final Class<T> type) { return fromJson(getGson(), json, type); } /** * Converts {@link String} to given type. * * @param json the json to convert. * @param type type type json will be converted to. * @return instance of type */ public static <T> T fromJson(final String json, @NonNull final Type type) { return fromJson(getGson(), json, type); } /** * Converts {@link Reader} to given type. * * @param reader the reader to convert. * @param type type type json will be converted to. * @return instance of type */ public static <T> T fromJson(@NonNull final Reader reader, @NonNull final Class<T> type) { return fromJson(getGson(), reader, type); } /** * Converts {@link Reader} to given type. * * @param reader the reader to convert. * @param type type type json will be converted to. * @return instance of type */ public static <T> T fromJson(@NonNull final Reader reader, @NonNull final Type type) { return fromJson(getGson(), reader, type); } /** * Converts {@link String} to given type. * * @param gson The gson. * @param json The json to convert. * @param type Type json will be converted to. * @return instance of type */ public static <T> T fromJson(@NonNull final Gson gson, final String json, @NonNull final Class<T> type) { return gson.fromJson(json, type); } /** * Converts {@link String} to given type. * * @param gson The gson. * @param json the json to convert. * @param type type type json will be converted to. * @return instance of type */ public static <T> T fromJson(@NonNull final Gson gson, final String json, @NonNull final Type type) { return gson.fromJson(json, type); } /** * Converts {@link Reader} to given type. * * @param gson The gson. * @param reader the reader to convert. * @param type type type json will be converted to. * @return instance of type */ public static <T> T fromJson(@NonNull final Gson gson, final Reader reader, @NonNull final Class<T> type) { return gson.fromJson(reader, type); } /** * Converts {@link Reader} to given type. * * @param gson The gson. * @param reader the reader to convert. * @param type type type json will be converted to. * @return instance of type */ public static <T> T fromJson(@NonNull final Gson gson, final Reader reader, @NonNull final Type type) { return gson.fromJson(reader, type); } /** * Return the type of {@link List} with the {@code type}. * * @param type The type. * @return the type of {@link List} with the {@code type} */ public static Type getListType(@NonNull final Type type) { return TypeToken.getParameterized(List.class, type).getType(); } /** * Return the type of {@link Set} with the {@code type}. * * @param type The type. * @return the type of {@link Set} with the {@code type} */ public static Type getSetType(@NonNull final Type type) { return TypeToken.getParameterized(Set.class, type).getType(); } /** * Return the type of map with the {@code keyType} and {@code valueType}. * * @param keyType The type of key. * @param valueType The type of value. * @return the type of map with the {@code keyType} and {@code valueType} */ public static Type getMapType(@NonNull final Type keyType, @NonNull final Type valueType) { return TypeToken.getParameterized(Map.class, keyType, valueType).getType(); } /** * Return the type of array with the {@code type}. * * @param type The type. * @return the type of map with the {@code type} */ public static Type getArrayType(@NonNull final Type type) { return TypeToken.getArray(type).getType(); } /** * Return the type of {@code rawType} with the {@code typeArguments}. * * @param rawType The raw type. * @param typeArguments The type of arguments. * @return the type of map with the {@code type} */ public static Type getType(@NonNull final Type rawType, @NonNull final Type... typeArguments) { return TypeToken.getParameterized(rawType, typeArguments).getType(); } static Gson getGson4LogUtils() { Gson gson4LogUtils = GSONS.get(KEY_LOG_UTILS); if (gson4LogUtils == null) { gson4LogUtils = new GsonBuilder().setPrettyPrinting().serializeNulls().create(); GSONS.put(KEY_LOG_UTILS, gson4LogUtils); } return gson4LogUtils; } private static Gson createGson() { return new GsonBuilder().serializeNulls().disableHtmlEscaping().create(); }}这个Gson工具类泉源于AndroidUtilCode工具类开源库，主要实现了一下几种功能呢：
- 设置署理对象：setGsonDelegate();
- 设置Gson对象：setGson();
- 获取Gson对象：getGson();
- 对账转Json字符串：toJson()，这个方法常用于服务器哀求利用Json转达参数；
- Json转对象：fromJson();
- 获取链表范例：getListType();
- 获取聚集范例：getSetType();
- 获取字典范例：getMapType();
- 获取数组范例：getArrayType();
- 获取范例：getType()。
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