Android轻量级JSON序列化和反序列化

文章由LinuxBoy分享于2019-03-31 09:03:45热评（65）

Android轻量级JSON序列化和反序列化

最近开发一直使用JSON数据传输，网络中流程的JSON解析导入包太多了，在网上找了下，结合自己改编，简单实现JSON解析，支持集合和对象泛化。 [java]

package com.callgetway.util;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONStringer;
import Android.util.Log;
/**
* @author keane
* @version 1.0
*
*/
public class JSONHelper {
private static String TAG = "JSONHelper";
/**
* 将对象转换成Json字符串
* @param obj
* @return
*/
public static String toJSON(Object obj) {
JSONStringer js = new JSONStringer();
serialize(js, obj);
Log.d(TAG, "JSONHelper toJSON :" + js.toString());
return js.toString();
}
/**
* 序列化为JSON
* @param js
* @param o
*/
private static void serialize(JSONStringer js, Object o) {
if (isNull(o)) {
try {
js.value(null);
} catch (JSONException e) {
e.printStackTrace();
}
return;
}
Class<?> clazz = o.getClass();
if (isObject(clazz)) { // 对象
serializeObject(js, o);
} else if (isArray(clazz)) { // 数组
serializeArray(js, o);
} else if (isCollection(clazz)) { // 集合
Collection<?> collection = (Collection<?>) o;
serializeCollect(js, collection);
} else { // 单个值
try {
js.value(o);
} catch (JSONException e) {
e.printStackTrace();
}
}
}
/**
* 序列化数组
* @param js
* @param array
*/
private static void serializeArray(JSONStringer js, Object array) {
try {
js.array();
for (int i = 0; i < Array.getLength(array); ++i) {
Object o = Array.get(array, i);
serialize(js, o);
}
js.endArray();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 序列化集合
* @param js
* @param collection
*/
private static void serializeCollect(JSONStringer js, Collection<?> collection) {
try {
js.array();
for (Object o : collection) {
serialize(js, o);
}
js.endArray();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 序列化对象
* @param js
* @param obj
*/
private static void serializeObject(JSONStringer js, Object obj) {
try {
js.object();
Class<? extends Object> objClazz = obj.getClass();
Method[] methods = objClazz.getDeclaredMethods();
Field[] fields = objClazz.getDeclaredFields();
for (Field field : fields) {
try {
String fieldType = field.getType().getSimpleName();
String fieldGetName = parseMethodName(field.getName(),"get");
if (!haveMethod(methods, fieldGetName)) {
continue;
}
Method fieldGetMet = objClazz.getMethod(fieldGetName, new Class[] {});
Object fieldVal = fieldGetMet.invoke(obj, new Object[] {});
String result = null;
if ("Date".equals(fieldType)) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss",
Locale.US);
result = sdf.format((Date)fieldVal);
} else {
if (null != fieldVal) {
result = String.valueOf(fieldVal);
}
}
js.key(field.getName());
serialize(js, result);
} catch (Exception e) {
continue;
}
}
js.endObject();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 判断是否存在某属性的 get方法
*
* @param methods
* @param fieldGetMet
* @return boolean
*/
public static boolean haveMethod(Method[] methods, String fieldMethod) {
for (Method met : methods) {
if (fieldMethod.equals(met.getName())) {
return true;
}
}
return false;
}
/**
* 拼接某属性的 get或者set方法
* @param fieldName
* @param methodType
* @return
*/
public static String parseMethodName(String fieldName,String methodType) {
if (null == fieldName || "".equals(fieldName)) {
return null;
}
return methodType + fieldName.substring(0, 1).toUpperCase()
+ fieldName.substring(1);
}
/**
* set属性的值到Bean
* @param obj
* @param valMap
*/
public static void setFieldValue(Object obj, Map<String, String> valMap) {
Class<?> cls = obj.getClass();
// 取出bean里的所有方法
Method[] methods = cls.getDeclaredMethods();
Field[] fields = cls.getDeclaredFields();
for (Field field : fields) {
try {
String setMetodName = parseMethodName(field.getName(),"set");
if (!haveMethod(methods, setMetodName)) {
continue;
}
Method fieldMethod = cls.getMethod(setMetodName, field
.getType());
String value = valMap.get(field.getName());
if (null != value && !"".equals(value)) {
String fieldType = field.getType().getSimpleName();
if ("String".equals(fieldType)) {
fieldMethod.invoke(obj, value);
} else if ("Date".equals(fieldType)) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss",Locale.US);
Date temp = sdf.parse(value);
fieldMethod.invoke(obj, temp);
} else if ("Integer".equals(fieldType)
|| "int".equals(fieldType)) {
Integer intval = Integer.parseInt(value);
fieldMethod.invoke(obj, intval);
} else if ("Long".equalsIgnoreCase(fieldType)) {
Long temp = Long.parseLong(value);
fieldMethod.invoke(obj, temp);
} else if ("Double".equalsIgnoreCase(fieldType)) {
Double temp = Double.parseDouble(value);
fieldMethod.invoke(obj, temp);
} else if ("Boolean".equalsIgnoreCase(fieldType)) {
Boolean temp = Boolean.parseBoolean(value);
fieldMethod.invoke(obj, temp);
} else {
System.out.println("setFieldValue not supper type:" + fieldType);
}
}
} catch (Exception e) {
continue;
}
}
}
/**
* 对象转Map
* @param obj
* @return
*/
public static Map<String, String> getFieldValueMap(Object obj) {
Class<?> cls = obj.getClass();
Map<String, String> valueMap = new HashMap<String, String>();
// 取出bean里的所有方法
Method[] methods = cls.getDeclaredMethods();
Field[] fields = cls.getDeclaredFields();
for (Field field : fields) {
try {
String fieldType = field.getType().getSimpleName();
String fieldGetName = parseMethodName(field.getName(),"get");
if (!haveMethod(methods, fieldGetName)) {
continue;
}
Method fieldGetMet = cls.getMethod(fieldGetName, new Class[] {});
Object fieldVal = fieldGetMet.invoke(obj, new Object[] {});
String result = null;
if ("Date".equals(fieldType)) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss",Locale.CHINA);
result = sdf.format((Date)fieldVal);
} else {
if (null != fieldVal) {
result = String.valueOf(fieldVal);
}
}
valueMap.put(field.getName(), result);
} catch (Exception e) {
continue;
}
}
return valueMap;
}
/**
* 给对象的字段赋值
* @param obj
* @param fieldSetMethod
* @param fieldType
* @param value
*/
public static void setFiedlValue(Object obj,Method fieldSetMethod,String fieldType,Object value){
try {
if (null != value && !"".equals(value)) {
if ("String".equals(fieldType)) {
fieldSetMethod.invoke(obj, value.toString());
} else if ("Date".equals(fieldType)) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss",Locale.CHINA);
Date temp = sdf.parse(value.toString());
fieldSetMethod.invoke(obj, temp);
} else if ("Integer".equals(fieldType)
|| "int".equals(fieldType)) {
Integer intval = Integer.parseInt(value.toString());
fieldSetMethod.invoke(obj, intval);
} else if ("Long".equalsIgnoreCase(fieldType)) {
Long temp = Long.parseLong(value.toString());
fieldSetMethod.invoke(obj, temp);
} else if ("Double".equalsIgnoreCase(fieldType)) {
Double temp = Double.parseDouble(value.toString());
fieldSetMethod.invoke(obj, temp);
} else if ("Boolean".equalsIgnoreCase(fieldType)) {
Boolean temp = Boolean.parseBoolean(value.toString());
fieldSetMethod.invoke(obj, temp);
} else {
fieldSetMethod.invoke(obj, value);
Log.e(TAG, TAG + ">>>>setFiedlValue -> not supper type" + fieldType);
}
}
} catch (Exception e) {
Log.e(TAG, TAG + ">>>>>>>>>>set value error.",e);
}
}
/**
* 反序列化简单对象
* @param jo
* @param clazz
* @return
*/
public static <T> T parseObject(JSONObject jo, Class<T> clazz) {
if (clazz == null || isNull(jo)) {
return null;
}
T obj = newInstance(clazz);
if (obj == null) {
return null;
}
if(isMap(clazz)){
setField(obj,jo);
}else{
// 取出bean里的所有方法
Method[] methods = clazz.getDeclaredMethods();
Field[] fields = clazz.getDeclaredFields();
for (Field f : fields) {
String setMetodName = parseMethodName(f.getName(),"set");
if (!haveMethod(methods, setMetodName)) {
continue;
}
try {
Method fieldMethod = clazz.getMethod(setMetodName, f.getType());
setField(obj,fieldMethod,f, jo);
} catch (Exception e) {
e.printStackTrace();
}
}
}
return obj;
}
/**
* 反序列化简单对象
* @param jsonString
* @param clazz
* @return
*/
public static <T> T parseObject(String jsonString, Class<T> clazz) {
if (clazz == null || jsonString == null || jsonString.length() == 0) {
return null;
}
JSONObject jo = null;
try {
jo = new JSONObject(jsonString);
} catch (JSONException e) {
e.printStackTrace();
}
if (isNull(jo)) {
return null;
}
return parseObject(jo, clazz);
}
/**
* 反序列化数组对象
* @param ja
* @param clazz
* @return
*/
public static <T> T[] parseArray(JSONArray ja, Class<T> clazz) {
if (clazz == null || isNull(ja)) {
return null;
}
int len = ja.length();
@SuppressWarnings("unchecked")
T[] array = (T[]) Array.newInstance(clazz, len);
for (int i = 0; i < len; ++i) {
try {
JSONObject jo = ja.getJSONObject(i);
T o = parseObject(jo, clazz);
array[i] = o;
} catch (JSONException e) {
e.printStackTrace();
}
}
return array;
}
/**
* 反序列化数组对象
* @param jsonString
* @param clazz
* @return
*/
public static <T> T[] parseArray(String jsonString, Class<T> clazz) {
if (clazz == null || jsonString == null || jsonString.length() == 0) {
return null;
}
JSONArray jo = null;
try {
jo = new JSONArray(jsonString);
} catch (JSONException e) {
e.printStackTrace();
}
if (isNull(jo)) {
return null;
}
return parseArray(jo, clazz);
}
/**
* 反序列化泛型集合
* @param ja
* @param collectionClazz
* @param genericType
* @return
*/
@SuppressWarnings("unchecked")
public static <T> Collection<T> parseCollection(JSONArray ja, Class<?> collectionClazz,
Class<T> genericType) {
if (collectionClazz == null || genericType == null || isNull(ja)) {
return null;
}
Collection<T> collection = (Collection<T>) newInstance(collectionClazz);
for (int i = 0; i < ja.length(); ++i) {
try {
JSONObject jo = ja.getJSONObject(i);
T o = parseObject(jo, genericType);
collection.add(o);
} catch (JSONException e) {
e.printStackTrace();
}
}
return collection;
}
/**
* 反序列化泛型集合
* @param jsonString
* @param collectionClazz
* @param genericType
* @return
*/
public static <T> Collection<T> parseCollection(String jsonString, Class<?> collectionClazz,
Class<T> genericType) {
if (collectionClazz == null || genericType == null || jsonString == null
|| jsonString.length() == 0) {
return null;
}
JSONArray jo = null;
try {
jo = new JSONArray(jsonString);
} catch (JSONException e) {
e.printStackTrace();
}
if (isNull(jo)) {
return null;
}
return parseCollection(jo, collectionClazz, genericType);
}
/**
* 根据类型创建对象
* @param clazz
* @return
*/
private static <T> T newInstance(Class<T> clazz) {
if (clazz == null)
return null;
T obj = null;
try {
obj = clazz.newInstance();
} catch (Exception e) {
e.printStackTrace();
}
return obj;
}
/**
* 设定Map的值
* @param obj
* @param jo
*/
private static void setField(Object obj, JSONObject jo) {
try {
@SuppressWarnings("unchecked")
Iterator<String> keyIter = jo.keys();
String key;
Object value;
@SuppressWarnings("unchecked")
Map<String, Object> valueMap = (Map<String, Object>) obj;
while (keyIter.hasNext()) {
key = (String) keyIter.next();
value = jo.get(key);
valueMap.put(key, value);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
/**
* 设定字段的值
* @param obj
* @param fieldSetMethod
* @param f
* @param jo
*/
private static void setField(Object obj, Method fieldSetMethod,Field f, JSONObject jo) {
String name = f.getName();
Class<?> clazz = f.getType();
try {
if (isArray(clazz)) { // 数组
Class<?> c = clazz.getComponentType();
JSONArray ja = jo.optJSONArray(name);
if (!isNull(ja)) {
Object array = parseArray(ja, c);
setFiedlValue(obj, fieldSetMethod, clazz.getSimpleName(), array);
}
} else if (isCollection(clazz)) { // 泛型集合
// 获取定义的泛型类型
Class<?> c = null;
Type gType = f.getGenericType();
if (gType instanceof ParameterizedType) {
ParameterizedType ptype = (ParameterizedType) gType;
Type[] targs = ptype.getActualTypeArguments();
if (targs != null && targs.length > 0) {
Type t = targs[0];
c = (Class<?>) t;
}
}
JSONArray ja = jo.optJSONArray(name);
if (!isNull(ja)) {
Object o = parseCollection(ja, clazz, c);
setFiedlValue(obj, fieldSetMethod, clazz.getSimpleName(), o);
}
} else if (isSingle(clazz)) { // 值类型
Object o = jo.opt(name);
if (o != null) {
setFiedlValue(obj, fieldSetMethod, clazz.getSimpleName(), o);
}
} else if (isObject(clazz)) { // 对象
JSONObject j = jo.optJSONObject(name);
if (!isNull(j)) {
Object o = parseObject(j, clazz);
setFiedlValue(obj, fieldSetMethod, clazz.getSimpleName(), o);
}
} else if (isList(clazz)) { // 列表
// JSONObject j = jo.optJSONObject(name);
// if (!isNull(j)) {
// Object o = parseObject(j, clazz);
// f.set(obj, o);
// }
} else {
throw new Exception("unknow type!");
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 设定字段的值
* @param obj
* @param f
* @param jo
*/
private static void setField(Object obj, Field f, JSONObject jo) {
String name = f.getName();
Class<?> clazz = f.getType();
try {
if (isArray(clazz)) { // 数组
Class<?> c = clazz.getComponentType();
JSONArray ja = jo.optJSONArray(name);
if (!isNull(ja)) {
Object array = parseArray(ja, c);
f.set(obj, array);
}
} else if (isCollection(clazz)) { // 泛型集合
// 获取定义的泛型类型
Class<?> c = null;
Type gType = f.getGenericType();
if (gType instanceof ParameterizedType) {
ParameterizedType ptype = (ParameterizedType) gType;
Type[] targs = ptype.getActualTypeArguments();
if (targs != null && targs.length > 0) {
Type t = targs[0];
c = (Class<?>) t;
}
}
JSONArray ja = jo.optJSONArray(name);
if (!isNull(ja)) {
Object o = parseCollection(ja, clazz, c);
f.set(obj, o);
}
} else if (isSingle(clazz)) { // 值类型
Object o = jo.opt(name);
if (o != null) {
f.set(obj, o);
}
} else if (isObject(clazz)) { // 对象
JSONObject j = jo.optJSONObject(name);
if (!isNull(j)) {
Object o = parseObject(j, clazz);
f.set(obj, o);
}
} else if (isList(clazz)) { // 列表
JSONObject j = jo.optJSONObject(name);
if (!isNull(j)) {
Object o = parseObject(j, clazz);
f.set(obj, o);
}
}else {
throw new Exception("unknow type!");
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 判断对象是否为空
* @param obj
* @return
*/
private static boolean isNull(Object obj) {
if (obj instanceof JSONObject) {
return JSONObject.NULL.equals(obj);
}
return obj == null;
}
/**
* 判断是否是值类型
* @param clazz
* @return
*/
private static boolean isSingle(Class<?> clazz) {
return isBoolean(clazz) || isNumber(clazz) || isString(clazz);
}
/**
* 是否布尔值
* @param clazz
* @return
*/
public static boolean isBoolean(Class<?> clazz) {
return (clazz != null)
&& ((Boolean.TYPE.isAssignableFrom(clazz)) || (Boolean.class
.isAssignableFrom(clazz)));
}
/**
* 是否数值
* @param clazz
* @return
*/
public static boolean isNumber(Class<?> clazz) {
return (clazz != null)
&& ((Byte.TYPE.isAssignableFrom(clazz)) || (Short.TYPE.isAssignableFrom(clazz))
|| (Integer.TYPE.isAssignableFrom(clazz))
|| (Long.TYPE.isAssignableFrom(clazz))
|| (Float.TYPE.isAssignableFrom(clazz))
|| (Double.TYPE.isAssignableFrom(clazz)) || (Number.class
.isAssignableFrom(clazz)));
}
/**
* 判断是否是字符串
* @param clazz
* @return
*/
public static boolean isString(Class<?> clazz) {
return (clazz != null)
&& ((String.class.isAssignableFrom(clazz))
|| (Character.TYPE.isAssignableFrom(clazz)) || (Character.class
.isAssignableFrom(clazz)));
}
/**
* 判断是否是对象
* @param clazz
* @return
*/
private static boolean isObject(Class<?> clazz) {
return clazz != null && !isSingle(clazz) && !isArray(clazz) && !isCollection(clazz);
}
/**
* 判断是否是数组
* @param clazz
* @return
*/
public static boolean isArray(Class<?> clazz) {
return clazz != null && clazz.isArray();
}
/**
* 判断是否是集合
* @param clazz
* @return
*/
public static boolean isCollection(Class<?> clazz) {
return clazz != null && Collection.class.isAssignableFrom(clazz);
}
/**
* 判断是否是Map
* @param clazz
* @return
*/
public static boolean isMap(Class<?> clazz) {
return clazz != null && Map.class.isAssignableFrom(clazz);
}
/**
* 判断是否是列表
* @param clazz
* @return
*/
public static boolean isList(Class<?> clazz) {
return clazz != null && List.class.isAssignableFrom(clazz);
}
}

测试代码：

[java]

public class User{
private String name;
private String password;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
void testObj(){
User user = new User();
user.setName("abcd");
user.setPassword("123456");
String jsonStrUser = JSONHelper.toJSON(user);
User jsonUser = JSONHelper.parseObject(jsonStrUser, User.class);
Map mapUser = JSONHelper.parseObject(jsonStrUser, HashMap.class);
}

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