java对象与json字符串互转的工具类
import java.beans.PropertyDescriptor;import java.lang.reflect.Array;import java.lang.reflect.InvocationTargetException;import java.math.BigDecimal;import java.math.BigInteger;import java.net.URLDecoder;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Collection;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Set;import java.util.Map.Entry;import ognl.OgnlOps;import org.apache.commons.lang.StringUtils;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.json.JSONArray;import org.json.JSONObject;import com.opensymphony.xwork.util.OgnlUtil;/** * java对象与json字符串互转的工具类 * */public class JsonUtil {/** * 将json字符串转成javabean * @param jsonStr 要转换的json字符串 * @param toClass 要转化到的类型 * @param childMap 该类型中集合字段的字段名和集合元素类型map * @return Object * @throws InvocationTargetException * @throws IllegalAccessException * @throws IllegalArgumentException */@SuppressWarnings("unchecked") public static Object json2Bean(Class toClass,String jsonValue,Map<String,Class> childMap) throws Exception{if( toClass == null || StringUtils.isBlank(jsonValue)) {return null;} try{ jsonValue= URLDecoder.decode(jsonValue, "utf-8"); }catch(Exception e){ throw new Exception("编码格式错误！"); }JSONObject object = null;try{ object= new JSONObject(jsonValue);}catch(Exception e){throw new Exception("json格式错误！");}Object obj = toClass.newInstance();Map<String,Object> sourceMap = toMap(object);PropertyDescriptor[] props = OgnlUtil.getPropertyDescriptors(obj);Map<String,Object> map = new HashMap<String,Object>();//参数不区分大小写for (PropertyDescriptor desc : props) { Set entrys = sourceMap.entrySet(); boolean contains = false; for(Iterator i = entrys.iterator();i.hasNext();){ Entry entry = (Entry) i.next(); if(((String)entry.getKey()).equalsIgnoreCase(desc.getName())){ map.put(desc.getName(), entry.getValue()); contains = true; break; } } if( contains ) {Object value = null;// 处理日期型// "yyyy-MM-dd'T'HH:mm:ss'Z'"此格式是由json2.js转换后的Date格式if(java.util.Date.class.isAssignableFrom(desc.getPropertyType())) { String date = (String) map.get(desc.getName()); if(!validateDate(date)){ throw new Exception(desc.getName()+"日期格式错误!"); } value = new SimpleDateFormat("yyyy-MM-dd").parse(date.trim());} else if(java.sql.Date.class.isAssignableFrom(desc.getPropertyType())) {String date = (String) map.get(desc.getName()); if(!validateDate(date)){ throw new Exception(desc.getName()+"日期格式错误!"); } value = new java.sql.Date(new SimpleDateFormat("yyyy-MM-dd").parse(date.trim()).getTime());} else if(Collection.class.isAssignableFrom(desc.getPropertyType())) { Class clz = childMap.get(desc.getName()); if(clz.isPrimitive() || CharSequence.class.isAssignableFrom(clz) || Number.class.isAssignableFrom(clz)) value = convertFromStringListSimple(map.get(desc.getName()).toString(),clz); else value = convertFromStringListComplex(map.get(desc.getName()).toString(),clz); } else { if(desc.getPropertyType().isPrimitive() || CharSequence.class.isAssignableFrom(desc.getPropertyType()) || Number.class.isAssignableFrom(desc.getPropertyType())){ try{ value = OgnlOps.convertValue(map.get(desc.getName()),desc.getPropertyType()); }catch(NumberFormatException e){ Class clz = desc.getPropertyType();if(clz == Integer.TYPE||clz == Short.TYPE||clz == Long.TYPE||clz == BigInteger.class) throw new Exception(desc.getName()+"应为整数!");else if(clz == Double.TYPE||clz == Float.TYPE||clz == BigDecimal.class) throw new Exception(desc.getName()+"应为数字!"); } } else { value = json2Bean(desc.getPropertyType(),map.get(desc.getName()).toString(),null); }}desc.getWriteMethod().invoke(obj, new Object[] { value });}} return obj;}/** * 将json字符串转成javabean 日期格式默认为yyyy-MM-dd HH:mm:ss * @param jsonStr 要转换的json字符串 * @param toClass 要转化到的类型 * @param childMap 该类型中集合字段的字段名和集合元素类型map * @param DateStyle 日期时间格式 * @return Object * @throws InvocationTargetException * @throws IllegalAccessException * @throws IllegalArgumentException * @throws ParseException */@SuppressWarnings("unchecked") public static Object json2Bean(Class toClass,String jsonValue,Map<String,Class> childMap,String DateStyle) throws Exception{if(StringUtils.isBlank(DateStyle)){DateStyle = DateUtil.DEFAULT_DATETIME_FORMAT;}if( toClass == null) {return null;} try{ jsonValue= URLDecoder.decode(jsonValue, "utf-8"); }catch(Exception e){ throw new Exception("编码格式错误！"); }JSONObject object = null;try{ object= new JSONObject(jsonValue);}catch(Exception e){throw new Exception("json格式错误！");}Object obj = toClass.newInstance();Map<String,Object> sourceMap = toMap(object);PropertyDescriptor[] props = OgnlUtil.getPropertyDescriptors(obj);Map<String,Object> map = new HashMap<String,Object>();//参数不区分大小写for (PropertyDescriptor desc : props) { Set entrys = sourceMap.entrySet(); boolean contains = false; for(Iterator i = entrys.iterator();i.hasNext();){ Entry entry = (Entry) i.next(); if(((String)entry.getKey()).equalsIgnoreCase(desc.getName())){ map.put(desc.getName(), entry.getValue()); contains = true; break; } } if( contains ) {Object value = null;// 处理日期型// "yyyy-MM-dd'T'HH:mm:ss'Z'"此格式是由json2.js转换后的Date格式if(java.util.Date.class.isAssignableFrom(desc.getPropertyType())) { String date = (String) map.get(desc.getName()); try{ value = new SimpleDateFormat(DateStyle).parse(date.trim()); }catch(ParseException e3){ throw new Exception(desc.getName()+"="+date+";日期格式错误!"); }} else if(java.sql.Date.class.isAssignableFrom(desc.getPropertyType())) { String date = (String) map.get(desc.getName()); try{value = new java.sql.Date(new SimpleDateFormat(DateStyle).parse(date.trim()).getTime()); }catch(ParseException e3){ throw new Exception(desc.getName()+"="+date+";日期格式错误!"); }} else if(Collection.class.isAssignableFrom(desc.getPropertyType())) { Class clz = childMap.get(desc.getName()); if(clz.isPrimitive() || CharSequence.class.isAssignableFrom(clz) || Number.class.isAssignableFrom(clz)) value = convertFromStringListSimple(map.get(desc.getName()).toString(),clz); else value = convertFromStringListComplex(map.get(desc.getName()).toString(),clz); } else { if(desc.getPropertyType().isPrimitive() || CharSequence.class.isAssignableFrom(desc.getPropertyType()) || Number.class.isAssignableFrom(desc.getPropertyType())){ try{ value = OgnlOps.convertValue(map.get(desc.getName()),desc.getPropertyType()); }catch(NumberFormatException e){ Class clz = desc.getPropertyType();if(clz == Integer.TYPE||clz == Short.TYPE||clz == Long.TYPE||clz == BigInteger.class) throw new Exception(desc.getName()+"应为整数!");else if(clz == Double.TYPE||clz == Float.TYPE||clz == BigDecimal.class) throw new Exception(desc.getName()+"应为数字!"); } } else { value = json2Bean(desc.getPropertyType(),map.get(desc.getName()).toString(),null); }}desc.getWriteMethod().invoke(obj, new Object[] { value });}} return obj;}public static Map<String,Object> json2Map(String jsonValue) throws Exception{if (StringUtils.isBlank(jsonValue)) {return null;}try {jsonValue = URLDecoder.decode(jsonValue, "utf-8");} catch (Exception e) {throw new Exception("编码格式错误！");}JSONObject object = null;try {object = new JSONObject(jsonValue);} catch (Exception e) {throw new Exception("json格式错误！");}return toMap(object);}@SuppressWarnings("unchecked") public static List<Map<String,String>> json2List(String jsonValue) throws Exception{if (StringUtils.isBlank(jsonValue)) {return null;}try {jsonValue = URLDecoder.decode(jsonValue, "utf-8");} catch (Exception e) {throw new Exception("编码格式错误！");}JSONArray array = new JSONArray(jsonValue);List<Map<String,String>> jsonList = new ArrayList<Map<String,String>>();for(int i=0;i<array.length();i++){Map jsonMap = toMap(array.getJSONObject(i));jsonList.add(jsonMap);}return jsonList;}public static boolean validateDate(String date){ if(date == null ||date.trim().length() != 10) return false; else { date = date.trim(); String[] param = date.split("-"); if(param[0].length() != 4) return false; int month = Integer.parseInt(param[1]); if(month < 1 || month > 12) return false; int day = Integer.parseInt(param[2]); if(day < 1 || day > 31) return false; } return true;} @SuppressWarnings("unchecked") private static Object convertFromStringListSimple (String jsonValue,Class toClass) throws Exception { if( toClass == null) {return null;} ArrayList<Object> list = new ArrayList<Object>();JSONArray array = new JSONArray(jsonValue);int i;Object value = null; for(i = 0; i < array.length(); i++) { Object property = array.get(i); if(java.util.Date.class.isAssignableFrom(toClass)) { String date = (String)property; if(!validateDate(date)){ throw new Exception("日期格式错误!"); }value = new SimpleDateFormat("yyyy-MM-dd").parse(date.trim()); } else if(java.sql.Date.class.isAssignableFrom(toClass)){ String date = (String)property; if(!validateDate(date)){ throw new Exception("日期格式错误!"); } value = new java.sql.Date(new SimpleDateFormat("yyyy-MM-dd").parse(date.trim()).getTime()); }else value = OgnlOps.convertValue(property, toClass); list.add(value); } return list;} @SuppressWarnings("unchecked") private static Object convertFromStringListComplex( String jsonValue, Class toClass) throws Exception{ if( toClass == null) {return null;}ArrayList<Object> list = new ArrayList<Object>();JSONArray array = new JSONArray(jsonValue);for (int i = 0; i < array.length(); i++) {Object obj = toClass.newInstance();Map map = toMap(array.getJSONObject(i));PropertyDescriptor[] props = OgnlUtil.getPropertyDescriptors(obj);for (PropertyDescriptor desc : props) {if( map.containsKey(desc.getName()) ) {Object value = null;// 处理日期型// "yyyy-MM-dd'T'HH:mm:ss'Z'"此格式是由json2.js转换后的Date格式if(java.util.Date.class.isAssignableFrom(desc.getPropertyType())) {String date = (String) map.get(desc.getName()); if(!validateDate(date)){ throw new Exception(desc.getName()+"日期格式错误!"); } value = new SimpleDateFormat("yyyy-MM-dd").parse(date.trim());} else if(java.sql.Date.class.isAssignableFrom(desc.getPropertyType())) {String date = (String) map.get(desc.getName()); if(!validateDate(date)){ throw new Exception(desc.getName()+"日期格式错误!"); } value = new java.sql.Date(new SimpleDateFormat("yyyy-MM-dd").parse(date.trim()).getTime());} else { try{value = OgnlOps.convertValue(map.get(desc.getName()),desc.getPropertyType());}catch(NumberFormatException e){Class clz = desc.getPropertyType();if(clz == Integer.class||clz == Short.class||clz == Long.class||clz == BigInteger.class) throw new Exception(desc.getName()+"应为整数!");else if(clz == Double.class||clz == Float.class||clz == BigDecimal.class) throw new Exception(desc.getName()+"应为数字!"); }}desc.getWriteMethod().invoke(obj, new Object[] { value });}}list.add(obj);} return list;}@SuppressWarnings("unchecked") private static Map<String,Object> toMap(JSONObject object) throws Exception {HashMap<String, Object> map = new HashMap<String, Object>();Iterator iter = object.keys();while (iter.hasNext()) {String key = (String) iter.next();Object val = object.get(key);if(val != null && !val.toString().trim().equals(""))map.put(key,val);}return map;}/** * 将javabean转成json字符串 * @param cls 要转的javabean类型 * @param value 要转的javabean * @return String * */public static String bean2Json(Class<?> cls, Object value) {try {return transToJSONObject(cls, value).toString();} catch (Exception e) {log.error("转换jsonObject失败",e);return null;}}// 将value转换成JSONObject@SuppressWarnings("unchecked") private static Object transToJSONObject(Class<?> cls, Object value) throws Exception {Object json = null;if (value != null) {if (Collection.class.isAssignableFrom(cls)) {// 列表sIterator iter = ((Collection) value).iterator();JSONArray array = new JSONArray();while (iter.hasNext()) {Object element = iter.next();if( element != null ) {array.put(transToJSONObject(element.getClass(), element));}}json = array;} else if (cls.isArray()) {// 数组JSONArray array = new JSONArray();int length = Array.getLength(value);for (int i = 0; i < length; i++) {Object element = Array.get(value, i);if( element != null ) {array.put(transToJSONObject(element.getClass(), element));}}json = array;} else if (Map.class.isAssignableFrom(cls)) {// 映射Iterator iter = ((Map) value).entrySet().iterator();JSONObject object = new JSONObject();while (iter.hasNext()) {Map.Entry entry = (Map.Entry) iter.next();Object v = entry.getValue();if( v != null ) {object.put(entry.getKey().toString(), transToJSONObject(v.getClass(), v));}}json = object;} else if (cls.isPrimitive() || CharSequence.class.isAssignableFrom(cls) || Number.class.isAssignableFrom(cls)) {// 基本类型、数值或字符串if (cls == Boolean.TYPE|| cls == Integer.TYPE|| cls == Float.TYPE|| cls == Double.TYPE|| cls == Long.TYPE|| cls == Short.TYPE|| cls == Byte.TYPE|| cls.isAssignableFrom(Number.class)) {json = value;} else {json = value.toString();}} else if (java.util.Date.class.isAssignableFrom(cls) || java.sql.Date.class.isAssignableFrom(cls)) {json = value.toString();} else {// 对象Map map = OgnlUtil.getBeanMap(value);JSONObject object = new JSONObject();if ( map != null ) {Iterator iter = map.entrySet().iterator();while (iter.hasNext()) {Map.Entry element = (Map.Entry) iter.next();Object v = element.getValue();if( v != null ) {object.put((String)element.getKey(), transToJSONObject(v.getClass(), v));}else{object.put((String)element.getKey(), "null");}}json = object;}}}return json == null ? "" : json;}@SuppressWarnings("unchecked") public static void main(String args[]) throws Exception{String str = "["1","2","3","4"]";ArrayList list = (ArrayList)JsonUtil.json2Bean(ArrayList.class, str, null);System.out.println(list.get(0));}private static Log log = LogFactory.getLog(JsonUtil.class);}?