JsonOM解析

好久没有写博客了，一直很懒。

客户端和服务器数据交换时，现在最流行的是Json格式，因此我们常常需要去解析Json字符串成对象。手动解析工作量太大了，影响工作进度，也是一种体力活。我们可以用Gson工具包来解析，它是一种Json ORM，可以帮助我们把Json字符串解析成对象。可是gson-2.3.jar包230k大小，为了一个json解析功能导入如此大的jar包，怎么给自己的应用加分？

因此我自己写了一个工具类来替代gson，一切完美！

import java.lang.reflect.Field;import java.lang.reflect.ParameterizedType;import java.lang.reflect.Type;import java.util.ArrayList;import java.util.List;import org.json.JSONArray;import org.json.JSONObject;/** * Json工具类 * @author Davee * @since 2015-10-30 */public class JsonUtil {/** * 解析json字符串至对象类型 * @param jsonStr Json格式字符串 * @param clazz 转换对象 * @return */public static <T>T parseJson(String jsonStr, Class<T> clazz) {T result = null;if (clazz == null || jsonStr == null || jsonStr.length() == 0) {return result;}try {JSONObject jsonRoot = new JSONObject(jsonStr);result = (T)clazz.newInstance();recursion(result, clazz, jsonRoot);} catch (Exception e) {e.printStackTrace();}return result;}private static <T> void recursion(T result, Class<?> clazz, JSONObject jsonRoot) {if (jsonRoot == null) return;try {Field[] fields = clazz.getDeclaredFields();if (fields != null) {for (Field field : fields) {setFieldValue(result, field, jsonRoot);}}} catch (Exception e) {e.printStackTrace();}Class<?> superClazz = clazz.getSuperclass();if (superClazz != Object.class) {//没有了父类recursion(result, superClazz, jsonRoot);}}private static void setFieldValue(Object obj, Field field, JSONObject json) {field.setAccessible(true);try {if (field.getType().isPrimitive()) {if (field.getType() == int.class) field.setInt(obj, json.optInt(field.getName()));else if (field.getType() == long.class) field.setLong(obj, json.optLong(field.getName()));else if (field.getType() == byte.class) field.setByte(obj, Byte.parseByte(json.optString(field.getName())));else if (field.getType() == short.class) field.setShort(obj, Short.parseShort(json.optString(field.getName())));else if (field.getType() == float.class) field.setFloat(obj, Float.parseFloat(json.optString(field.getName())));else if (field.getType() == double.class) field.setDouble(obj, json.optDouble(field.getName()));else if (field.getType() == char.class) {String value = json.optString(field.getName());if (value != null && value.length() > 0) field.setChar(obj, value.charAt(0));}else if (field.getType() == boolean.class) {String value = json.optString(field.getName());if (value == null || value.length() == 0|| "false".equalsIgnoreCase(value)|| "0".equals(value)|| "NULL".equalsIgnoreCase(value)) field.setBoolean(obj, false);else field.setBoolean(obj, true);}} else if (field.getType() == String.class) {field.set(obj, json.optString(field.getName()));} else if (field.getType() == java.util.Date.class || field.getType() == java.sql.Date.class) {field.set(obj, DateFormatUtil.stringToDateTime(json.optString(field.getName())));} else if (field.getType() == Integer.class) {field.set(obj, json.optInt(field.getName()));} else if (field.getType() == Long.class) {field.set(obj, json.optLong(field.getName()));} else if (field.getType() == Byte.class) {field.set(obj, Byte.parseByte(json.optString(field.getName())));} else if (field.getType() == Short.class) {field.set(obj, Short.parseShort(json.optString(field.getName())));} else if (field.getType() == Float.class) {field.set(obj, Float.parseFloat(json.optString(field.getName())));} else if (field.getType() == Double.class) {field.set(obj, json.optDouble(field.getName()));} else if (field.getType() == Character.class) {String value = json.optString(field.getName());if (value != null && value.length() > 0) field.set(obj, (Character)(value.charAt(0)));} else if (field.getType() == Boolean.class) {String value = json.optString(field.getName());if (value == null || value.length() == 0|| "false".equalsIgnoreCase(value)|| "0".equals(value)|| "NULL".equalsIgnoreCase(value)) field.set(obj, false);else field.set(obj, true);}//非基本类型else if (List.class.isAssignableFrom(field.getType())) {//field类型是否是List类或List子孙类Type type = field.getGenericType();if (type != null) {if (type instanceof ParameterizedType) {Class<?> genericClazz = (Class<?>)((ParameterizedType)type).getActualTypeArguments()[0];JSONArray jsonArray = json.optJSONArray(field.getName());if (jsonArray != null) {List<Object> list = new ArrayList<Object>();field.set(obj, list);for (int i=0,size=jsonArray.length(); i<size; i++) {if (genericClazz == String.class) {list.add(jsonArray.optString(i));} else if (genericClazz == java.util.Date.class || genericClazz == java.sql.Date.class) {list.add(DateFormatUtil.stringToDateTime(json.optString(field.getName())));} else if (genericClazz == Integer.class) {list.add(json.optInt(field.getName()));} else if (genericClazz == Long.class) {list.add(json.optLong(field.getName()));} else if (genericClazz == Byte.class) {list.add(Byte.parseByte(json.optString(field.getName())));} else if (genericClazz == Short.class) {list.add(Short.parseShort(json.optString(field.getName())));} else if (genericClazz == Float.class) {list.add(Float.parseFloat(json.optString(field.getName())));} else if (genericClazz == Double.class) {list.add(json.optDouble(field.getName()));} else if (genericClazz == Character.class) {String value = json.optString(field.getName());if (value != null && value.length() > 0) list.add((Character)(value.charAt(0)));} else if (genericClazz == Boolean.class) {String value = json.optString(field.getName());if (value == null || value.length() == 0|| "false".equalsIgnoreCase(value)|| "0".equals(value)|| "NULL".equalsIgnoreCase(value)) list.add(false);else list.add(true);} else {Object childObj = genericClazz.newInstance();list.add(childObj);recursion(childObj, genericClazz, jsonArray.optJSONObject(i));}}} else {field.set(obj, null);}} else {JSONArray jsonArray = json.optJSONArray(field.getName());if (jsonArray != null) {List<Object> list = new ArrayList<Object>();field.set(obj, list);for (int i=0,size=jsonArray.length(); i<size; i++) {list.add(jsonArray.opt(i));}} else {field.set(obj, null);}}}}else {//自定义类型Object childObj = field.getType().newInstance();field.set(obj, childObj);recursion(childObj, field.getType(), json.optJSONObject(field.getName()));}} catch (Exception e) {e.printStackTrace();}}}