JSON與Java物件互轉 工具類
阿新 • • 發佈：2019-02-01
話不多說，上程式碼~
import java.io.Serializable; import java.lang.reflect.Field; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.Iterator; import java.util.List; import java.util.Map; import org.apache.log4j.Logger; import org.json.JSONArray; import org.json.JSONObject; class shop implements Serializable{ private static final long serialVersionUID = 1L; String name; Date openTime; Date closeTime; public String getName() { return name; } public void setName(String name) { this.name = name; } public Date getOpenTime() { return openTime; } public void setOpenTime(Date openTime) { this.openTime = openTime; } public Date getCloseTime() { return closeTime; } public void setCloseTime(Date closeTime) { this.closeTime = closeTime; } } public class JSON { static Logger logger = Logger.getLogger(JSON.class); public static void main(String[] args) { shop s1 = new shop(); s1.setName("1.."); s1.setOpenTime(new Date()); try { System.out.println(JSON.toJson(s1)); String s = "{\"name\":\"1..\",\"openTime\":\"2018-4-13 16:36:27\"}"; shop ss = (shop)JSON.toObject(s, shop.class); System.out.println(ss.getOpenTime()); System.out.println(ss.getCloseTime()); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } /** * JSON字串轉成Object物件<br> * 此方法假設沒有把子類當成父類去使用<br> * 不然會出現解析出來的物件沒有子類屬性<br> * @param json * @param clazz * @return */ public static Object toObject(String json, Class<?> clazz) { return toObject(json, clazz, null, null); } /** * JSON字串轉成Object物件<br> * 此方法可以把子類當成父類去使用<br> * 但是需要提供一個map<br> * 告訴程式對應的(子)類<br> * @param json * @param map * @return */ public static Object toObject(String json, Map<String,String> map) { return toObject(json, null, null, map); } /** * JSON字串轉成Object物件<br> * 此方法可以把子類當成父類去使用<br> * 但是需要提供一個基礎的basePackage<br> * 並且在生成JSON的時候,也需要傳入這個basePackage * @param json * @return */ public static Object toObject(String json, String basePackage) { return toObject(json, null, basePackage, null); } /** * JSON字串轉成Object物件<br> * 此方法可以把子類當成父類去使用<br> * 但是需要提供一個基礎的basePackage<br> * 並且在生成JSON的時候,也需要傳入這個basePackage * @param json * @return */ public static Object toObject(String json, Class<?> clazz, String basePackage) { return toObject(json, clazz, basePackage, null); } /** * Object物件轉成JSON字串<br> * 此方法假設沒有把子類當成父類去使用<br> * 不然反轉的時候可能會出現解析出來的物件沒有子類屬性<br> * @param obj * @return */ public static String toJson(Object obj) { return toJson(obj, null, false); } /** * Object物件轉成JSON字串<br> * 對應反轉方法：toObject(String json, Map<String,String> map) * @param obj * @param createClassInfo * @return */ public static String toJson(Object obj, boolean createClassInfo) { return toJson(obj, null, createClassInfo); } /** * Object物件轉成JSON字串<br> * 對應反轉方法：toObject(String json, String basePackage) * @param obj * @return */ public static String toJson(Object obj, String basePackage) { return toJson(obj, basePackage, false); } public static String format(String json) { String fillStringUnit = " "; if (json == null || json.trim().length() == 0) { return null; } int fixedLenth = 0; ArrayList<String> tokenList = new ArrayList<String>(); { String jsonTemp = json; // 預讀取 while (jsonTemp.length() > 0) { String token = getToken(jsonTemp); jsonTemp = jsonTemp.substring(token.length()); token = token.trim(); tokenList.add(token); } } for (int i = 0; i < tokenList.size(); i++) { String token = tokenList.get(i); int length = token.getBytes().length; if (length > fixedLenth && i < tokenList.size() - 1 && tokenList.get(i + 1).equals(":")) { fixedLenth = length; } } StringBuilder buf = new StringBuilder(); int count = 0; for (int i = 0; i < tokenList.size(); i++) { String token = tokenList.get(i); if (token.equals(",")) { buf.append(token); doFill(buf, count, fillStringUnit); continue; } if (token.equals(":")) { buf.append(" ").append(token).append(" "); continue; } if (token.equals("{")) { String nextToken = tokenList.get(i + 1); if (nextToken.equals("}")) { i++; buf.append("{ }"); } else { count++; buf.append(token); doFill(buf, count, fillStringUnit); } continue; } if (token.equals("}")) { count--; doFill(buf, count, fillStringUnit); buf.append(token); continue; } if (token.equals("[")) { String nextToken = tokenList.get(i + 1); if (nextToken.equals("]")) { i++; buf.append("[ ]"); } else { count++; buf.append(token); doFill(buf, count, fillStringUnit); } continue; } if (token.equals("]")) { count--; doFill(buf, count, fillStringUnit); buf.append(token); continue; } buf.append(token); // 左對齊 if (i < tokenList.size() - 1 && tokenList.get(i + 1).equals(":")) { int fillLength = fixedLenth - token.getBytes().length; if (fillLength > 0) { for (int j = 0; j < fillLength; j++) { buf.append(" "); } } } } return buf.toString(); } /** * * @param json * JSONObject的字串形式 * @param clazz * Object的class * @return */ private static final String ENTER_REPLACE_STR = "\\n"; private static Object toObject(String json, Class<?> clazz, String basePackage, Map<String,String> map) { if (json == null || json.equals("")) { return json; } else { json = json.replace("\r\n", ENTER_REPLACE_STR).replace("\n", ENTER_REPLACE_STR); } Object object = null; try { if (json.charAt(0) == '[') { object = toList(json, clazz, basePackage, map); } else if (json.charAt(0) == '{'){ JSONObject infoObject = new JSONObject(json); // // if (infoObject.has("class")) { String className = infoObject.getString("class"); if (className != null) { if (map != null && map.get(className) != null) { clazz = Class.forName(map.get(className)); } else if (basePackage != null) { clazz = Class.forName(basePackage + className); } } } if (clazz == null) { throw new NullPointerException("clazz, basePackage, map不能全部為空。"); } object = clazz.newInstance(); // // Iterator<?> iterator = infoObject.keys(); while (iterator.hasNext()) { String key = (String) iterator.next(); Object fieldValue = null; List<Field> fields = getAllFields(null, clazz); for (int i = 0; i < fields.size(); i++) { Field field = fields.get(i); if (field.getName().equalsIgnoreCase(key)) { field.setAccessible(true); fieldValue = getFieldValue(field, infoObject, key, basePackage, map); if (null != fieldValue) { field.set(object, fieldValue); } field.setAccessible(false); } } } } else { return json; } } catch (Exception e) { e.printStackTrace(); logger.error("=====JSON EXCEPTION=====", e); } if (object instanceof List<?>) { List<?> list = (List<?>) object; for (int i = 0; i < list.size(); i++) { replaceObjectBr(list.get(i)); } } else { replaceObjectBr(object); } return object; } /** * * @param json * JSONArray的字串形式 * @param clazz * List內物件的class * @return */ private static List<?> toList(String json, Class<?> clazz, String basePackage, Map<String,String> map) { List<Object> list = null; try { JSONArray jsonArray = (JSONArray) new JSONArray(json); list = new ArrayList<Object>(); for (int i = 0; i < jsonArray.length(); i++) { String jsonvalue = jsonArray.getJSONObject(i).toString(); switch (getJSONType(jsonvalue)) { case JSON_TYPE_OBJECT: { /* JSONObject subObject = new JSONObject(jsonvalue); Class<?> newClazz = null; if (subObject.has("class")) { String className = subObject.getString("class"); if (className != null) { if (map != null && map.get(className) != null) { newClazz = Class.forName(map.get(className)); } else if (basePackage != null) { newClazz = Class.forName(basePackage + className); } } }*/ list.add(toObject(jsonvalue, clazz, basePackage, map)); break; } case JSON_TYPE_ARRAY: { List<?> infoList = toList(jsonvalue, clazz, basePackage, map); list.add(infoList); break; } default: break; } } } catch (Exception e) { e.printStackTrace(); logger.error("=====JSON EXCEPTION=====", e); } return list; } private static String toJson(Object obj, String basePackage, boolean createClass) { if (obj instanceof String) { return obj.toString(); } else { StringBuffer xmlBuffer = new StringBuffer(""); if (obj instanceof List<?>) { xmlBuffer.append("["); List<?> list = (List<?>) obj; for (int i = 0; i < list.size(); i++) { addObjectToBuffer(xmlBuffer, list.get(i), basePackage, createClass); if (i < list.size() - 1) { xmlBuffer.append(","); } } xmlBuffer.append("]"); } else { addObjectToBuffer(xmlBuffer, obj, basePackage, createClass); } return xmlBuffer.toString(); } } /** * 在JSON->Object的時候 * 根據JSON的鍵(key) * 生成Field的值(value) * @param field * @param infoObject * @param key * @param basePackage * @return * @throws Exception */ private static Object getFieldValue(Field field, JSONObject infoObject, String key, String basePackage, Map<String,String> map) throws Exception { Object fieldValue = null; Class<?> fieldClass = field.getType(); if (fieldClass.getSimpleName().toString().equals("int") || fieldClass.getSimpleName().toString().equals( "Integer")) { fieldValue = infoObject.getInt(key); } else if (fieldClass.getSimpleName().toString() .equalsIgnoreCase("String")) { fieldValue = infoObject.getString(key); } else if (fieldClass.getSimpleName().toString() .equalsIgnoreCase("double")) { fieldValue = infoObject.getDouble(key); } else if (fieldClass.getSimpleName().toString() .equalsIgnoreCase("boolean")) { fieldValue = infoObject.getBoolean(key); } else if (fieldClass.getSimpleName().toString() .equalsIgnoreCase("long")) { fieldValue = infoObject.getLong(key); } else if (fieldClass.getSimpleName().toString() .equalsIgnoreCase("Date")) { fieldValue = DateFormatUtil.toDate(infoObject.getString(key)); } else { String jsonvalue = infoObject.getString(key); switch (getJSONType(jsonvalue)) { case JSON_TYPE_OBJECT: { fieldValue = toObject(jsonvalue, fieldClass, basePackage, map); break; } case JSON_TYPE_ARRAY: { // 獲取泛型的class Type genericFieldType = field.getGenericType(); if (genericFieldType instanceof ParameterizedType) { ParameterizedType aType = (ParameterizedType) genericFieldType; Type[] fieldArgTypes = aType .getActualTypeArguments(); for (Type fieldArgType : fieldArgTypes) { Class<?> fieldArgClass = (Class<?>) fieldArgType; // if (map != null && map.get(key) != null) { // fieldArgClass = Class.forName(map.get(key)); // } fieldValue = toList(jsonvalue, fieldArgClass, basePackage, map); } } break; } default: break; } } return fieldValue; } private static List<Field> getAllFields(List<Field> fields, Class<?> clazz) { if (fields == null) { fields = new ArrayList<Field>(); } try { if (clazz.getSuperclass() != null) { Field[] fieldsSelf = clazz.getDeclaredFields(); for (Field field : fieldsSelf) { if (!Modifier.isFinal(field.getModifiers())) { fields.add(field); } } getAllFields(fields, clazz.getSuperclass()); } } catch (Exception e) { e.printStackTrace(); logger.error("=====JSON Exception=====", e); } return fields; } private static void addObjectToBuffer(StringBuffer xmlBuffer, Object obj, String basePackage, boolean createClass) { xmlBuffer.append("{"); // 獲取所有屬性 List<Field> fields = new ArrayList<Field>(); getAllFields(fields, obj.getClass()); for (int i = -1; i < fields.size(); i++) { if (i == -1) { if (basePackage != null || createClass) { // 加入類資訊 xmlBuffer.append("\""); xmlBuffer.append("class"); xmlBuffer.append("\":"); xmlBuffer.append("\""); if (basePackage != null) { xmlBuffer.append(obj.getClass().getName().replace(basePackage, "")); } else { xmlBuffer.append(obj.getClass().getSimpleName()); } xmlBuffer.append("\","); } continue; } Field field = fields.get(i); String fieldName = field.getName(); // 拼接GET方法名 Object fieldValue = null; Method method = null; try { String methodName = "get" + ((char) (fieldName.charAt(0) - 32)) + fieldName.substring(1); // System.out.println("methodName->" + methodName); method = obj.getClass().getMethod(methodName); } catch (Exception e) { String methodName = "is" + ((char) (fieldName.charAt(0) - 32)) + fieldName.substring(1); try { method = obj.getClass().getMethod(methodName); } catch (Exception e1) { e1.printStackTrace(); logger.error("=====To JSON Object Exception=====", e); } } if (method != null) { try { fieldValue = method.invoke(obj); } catch (Exception e) { e.printStackTrace(); logger.error("=====To JSON Object Exception=====", e); } } if (null != fieldValue) { xmlBuffer.append("\""); xmlBuffer.append(fieldName); xmlBuffer.append("\":"); if (fieldValue instanceof Date) { xmlBuffer.append("\""); xmlBuffer.append((DateFormatUtil.toTimeFormat((Date) fieldValue))); xmlBuffer.append("\""); } else if (fieldValue instanceof Integer || fieldValue instanceof Double || fieldValue instanceof Long || fieldValue instanceof Boolean) { xmlBuffer.append("\""); xmlBuffer.append(fieldValue.toString()); xmlBuffer.append("\""); } else if (fieldValue instanceof String) { xmlBuffer.append("\""); String str = fieldValue.toString(); xmlBuffer.append(str); xmlBuffer.append("\""); } else if (fieldValue instanceof List<?>) { addListToBuffer(xmlBuffer, fieldValue, basePackage, createClass); } else { addObjectToBuffer(xmlBuffer, fieldValue, basePackage, createClass); } xmlBuffer.append(","); } if (i == fields.size() - 1 && xmlBuffer.charAt(xmlBuffer.length() - 1) == ',') { xmlBuffer.deleteCharAt(xmlBuffer.length() - 1); } } xmlBuffer.append("}"); } private static void addListToBuffer(StringBuffer xmlBuffer, Object fieldvalue, String basePackage,boolean createClass) { xmlBuffer.append("["); List<?> v_list = (List<?>) fieldvalue; for (int i = 0; i < v_list.size(); i++) { addObjectToBuffer(xmlBuffer, v_list.get(i), basePackage, createClass); if (i < v_list.size() - 1) { xmlBuffer.append(","); } } xmlBuffer.append("]"); } private static JSON_TYPE getJSONType(String str) { final char[] strChar = str.substring(0, 1).toCharArray(); final char firstChar = strChar[0]; if (firstChar == '{') { return JSON_TYPE.JSON_TYPE_OBJECT; } else if (firstChar == '[') { return JSON_TYPE.JSON_TYPE_ARRAY; } else { return JSON_TYPE.JSON_TYPE_ERROR; } } private static String getToken(String json) { StringBuilder buf = new StringBuilder(); boolean isInYinHao = false; while (json.length() > 0) { String token = json.substring(0, 1); json = json.substring(1); if (!isInYinHao && (token.equals(":") || token.equals("{") || token.equals("}") || token.equals("[") || token.equals("]") || token.equals(","))) { if (buf.toString().trim().length() == 0) { buf.append(token); } break; } if (token.equals("\\")) { buf.append(token); buf.append(json.substring(0, 1)); json = json.substring(1); continue; } if (token.equals("\"")) { buf.append(token); if (isInYinHao) { break; } else { isInYinHao = true; continue; } } buf.append(token); } return buf.toString(); } private static void doFill(StringBuilder buf, int count, String fillStringUnit) { buf.append("\n"); for (int i = 0; i < count; i++) { buf.append(fillStringUnit); } } /** * 替換掉/n * @param obj 此Object不可以是List */ private static void replaceObjectBr(Object obj) { // 獲取所有屬性 Field[] fields = obj.getClass().getDeclaredFields(); for (int i = 0; i < fields.length; i++) { Field field = fields[i]; if (!Modifier.isFinal(field.getModifiers())) { continue; } field.setAccessible(true); Object fieldValue = null; try { fieldValue = field.get(obj); if (fieldValue instanceof Integer) { } else if (fieldValue instanceof Double) { } else if (fieldValue instanceof Boolean) { } else if (fieldValue instanceof Long) { } else if (fieldValue instanceof Date) { } else if (fieldValue instanceof String) { if (fieldValue != null) { String str = fieldValue.toString(); field.set(obj, str.replaceAll(ENTER_REPLACE_STR, "\n")); } }else if (fieldValue instanceof List<?>) { if (fieldValue != null) { List<?> list = (List<?>) fieldValue; for (int j = 0; j < list.size(); j++) { replaceObjectBr(list.get(j)); } } } else { if (fieldValue != null) { replaceObjectBr(fieldValue); } } } catch (Exception e) { e.printStackTrace(); logger.error("=====JSON Exception=====", e); } finally { field.setAccessible(false); } } } private enum JSON_TYPE { /** JSONObject */ JSON_TYPE_OBJECT, /** JSONArray */ JSON_TYPE_ARRAY, /** 不是JSON格式的字串 */ JSON_TYPE_ERROR } } class DateFormatUtil{ public static Object toDate(String string) { // TODO Auto-generated method stub SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); Date date = null; try { date = sdf.parse(string); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return date; } public static Object toTimeFormat(Date fieldValue) { return fieldValue.toLocaleString(); } }
自行刪除不必要的部分~