使用反射实现Java Bean的toString方法只打印非空参数

    @Override
    public String toString() {

        Class c = this.getClass();
        StringBuilder sb = new StringBuilder(c.getName() + ".toString：\n");
        Field[] fields = c.getDeclaredFields();
        Field.setAccessible(fields, true);
        try {
            for (Field field : fields) {
                if (null != field.get(this)) {
                    String fieldType = String.valueOf(field.getType());
                    String tmp = field.getName() + "=" + field.get(this) + "\n";
                    sb.append(tmp);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sb.toString();
    }