java List、Object、String、Map转json 工具类

这个工具类太吊了！！！

copy到相应的包中去即可。。

package com.util;import java.beans.IntrospectionException;import java.beans.Introspector;import java.beans.PropertyDescriptor;import java.math.BigDecimal;import java.math.BigInteger;import java.util.List;import java.util.Map;import java.util.Set;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;public class JsonUtil {private static Log log = LogFactory.getLog(JsonUtil.class);public static String object2json(Object obj) {StringBuilder json = new StringBuilder();if (obj == null) {json.append("\"\"");} else if (obj instanceof String || obj instanceof Integer|| obj instanceof Float || obj instanceof Boolean|| obj instanceof Short || obj instanceof Double|| obj instanceof Long || obj instanceof BigDecimal|| obj instanceof BigInteger || obj instanceof Byte) {json.append("\"").append(string2json(obj.toString())).append("\"");} else if (obj instanceof Object[]) {json.append(array2json((Object[]) obj));} else if (obj instanceof List) {json.append(list2json((List<?>) obj));} else if (obj instanceof Map) {json.append(map2json((Map<?, ?>) obj));} else if (obj instanceof Set) {json.append(set2json((Set<?>) obj));} else {json.append(bean2json(obj));}return json.toString();}public static String bean2json(Object bean) {StringBuilder json = new StringBuilder();json.append("{");PropertyDescriptor[] props = null;try {props = Introspector.getBeanInfo(bean.getClass(), Object.class).getPropertyDescriptors();} catch (IntrospectionException e) {}if (props != null) {for (int i = 0; i < props.length; i++) {try {String name = object2json(props[i].getName());String value = object2json(props[i].getReadMethod().invoke(bean));json.append(name);json.append(":");json.append(value);json.append(",");} catch (Exception e) {}}json.setCharAt(json.length() - 1, '}');} else {json.append("}");}return json.toString();}public static String list2json(List<?> list) {StringBuilder json = new StringBuilder();json.append("[");if (list != null && list.size() > 0) {for (Object obj : list) {json.append(object2json(obj));json.append(",");}json.setCharAt(json.length() - 1, ']');} else {json.append("]");}return json.toString();}public static String array2json(Object[] array) {StringBuilder json = new StringBuilder();json.append("[");if (array != null && array.length > 0) {for (Object obj : array) {json.append(object2json(obj));json.append(",");}json.setCharAt(json.length() - 1, ']');} else {json.append("]");}return json.toString();}public static String map2json(Map<?, ?> map) {StringBuilder json = new StringBuilder();json.append("{");if (map != null && map.size() > 0) {for (Object key : map.keySet()) {json.append(object2json(key));json.append(":");json.append(object2json(map.get(key)));json.append(",");}json.setCharAt(json.length() - 1, '}');} else {json.append("}");}return json.toString();}public static String set2json(Set<?> set) {StringBuilder json = new StringBuilder();json.append("[");if (set != null && set.size() > 0) {for (Object obj : set) {json.append(object2json(obj));json.append(",");}json.setCharAt(json.length() - 1, ']');} else {json.append("]");}return json.toString();}public static String string2json(String s) {if (s == null)return "";StringBuilder sb = new StringBuilder();for (int i = 0; i < s.length(); i++) {char ch = s.charAt(i);switch (ch) {case '"':sb.append("\\\"");break;case '\\':sb.append("\\\\");break;case '\b':sb.append("\\b");break;case '\f':sb.append("\\f");break;case '\n':sb.append("\\n");break;case '\r':sb.append("\\r");break;case '\t':sb.append("\\t");break;case '/':sb.append("\\/");break;default:if (ch >= '\u0000' && ch <= '\u001F') {String ss = Integer.toHexString(ch);sb.append("\\u");for (int k = 0; k < 4 - ss.length(); k++) {sb.append('0');}sb.append(ss.toUpperCase());} else {sb.append(ch);}}}return sb.toString();}}