日期:2014-05-16 浏览次数:20394 次
关于JSON的Java类库挺多的,但有时候不希望在项目里边引入这些JAR包,所以需要自己实现一些简单的工具类。本例就属于这种情况。本例中使用Java的反射机制,将简单的POJO对象转换成JSON字符串。
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/** * 将字符串首字母大写 * @param str * @return */ private static String transform(String str) { if (str == null || str.length() < 1) { return ""; } return str.substring(0, 1).toUpperCase() + str.substring(1); } /** * 将POJO对象转换成JSON格式的字符串 * @param obj * @return */ public static String pojo2Json(Object obj) { if (obj == null) { return ""; } Class clazz = obj.getClass(); Field[] fields = clazz.getDeclaredFields(); StringBuilder buff = new StringBuilder(); buff.append("{"); for (Field f : fields) { try { String methodName = "get" + transform(f.getName()); Object value=clazz.getDeclaredMethod(methodName).invoke(obj, null); buff.append("\""); buff.append(f.getName()); buff.append("\":"); if(value==null){ buff.append("\"\","); continue; } if(value instanceof Boolean){ buff.append((Boolean)value); buff.append(","); }else if(value instanceof Number){ buff.append((Number)value); buff.append(","); }else if(value instanceof Date){ buff.append("\""); buff.append(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format((Date)value)); buff.append("\","); }else{ buff.append("\""); buff.append(value.toString()); buff.append("\","); } } catch (SecurityException e) { //e.printStackTrace(); } catch (NoSuchMethodException e) { //e.printStackTrace(); } catch (IllegalArgumentException e) { //e.printStackTrace(); } catch (IllegalAccessException e) { //e.printStackTrace(); } catch (InvocationTargetException e) { //e.printStackTrace(); } } if (buff.length() > 1) { buff = buff.deleteCharAt(buff.length() - 1); } buff.append("}"); return buff.toString(); }