Java中把一个对象转换成JsonString

代码如下：

	/**
	 * Object To json String
	 * 
	 * @param obj
	 * 
	 * @return json String
	 */
	public static String objToJsonString(Object obj) {
		
		// 初始化返回值
		String json = "str_empty";

		if (obj == null) {
			return json;
		}

		StringBuilder buff = new StringBuilder();
		Field fields[] = obj.getClass().getFields();
		try {
			buff.append("[");
			buff.append("{");
			int i = 0;
			for (Field field : fields) {
				if (i != 0) {
					buff.append(",");
				}
				buff.append(field.getName());
				buff.append(":");
				buff.append("\"");
				buff.append(field.get(obj) == null ? "" : field.get(obj));
				buff.append("\"");
				i++;
			}
			buff.append("}");
			buff.append("]");
			json = buff.toString();
		} catch (Exception e) {
			throw new RuntimeException("cause:" + e.toString());
		}
		return json;
	}