java 实例化泛型且赋值

实例化泛型

Class <T> clazz = (Class <T>) ((ParameterizedType) new
 Entity().getClass().getGenericSuperclass()).getActualTypeArguments()[0];
        T dto = clazz.newInstance();

泛型方法

    /**
     *
     * @param clazz
     * @param book
     * @param sheetIndex
     * @param <T>
     * @return
     * @throws IllegalAccessException
     * @throws InstantiationException
     */
    public static <T> List<T> toEntity(Class<T> clazz,Workbook book, int sheetIndex) throws IllegalAccessException, InstantiationException {
        List<T> list = new ArrayList<>();
//        Class <T> clazz = (Class <T>) ((ParameterizedType) entity.getClass().getGenericSuperclass()).getActualTypeArguments()[0];
        T dto = clazz.newInstance();
        T dto2 = clazz.newInstance();
        Field[] fields = clazz.getDeclaredFields();
        Map<String, Field> fieldMap = new LinkedHashMap<>();
        for (Field field : fields) {
            String mod = Modifier.toString(field.getModifiers());
            System.out.println("mod = " + mod);
            // 跳过静态属性
            if (mod.indexOf("static") != -1) {
                continue;
            }

            // 取得注解的设置的属性值
            Description setField = field.getAnnotation(Description.class);
            if (setField != null) {
                String fieldName = setField.key();
                String fieldType = setField.value();
                //   必须,不然赋值会出现异常
                field.setAccessible(true);
                fieldMap.put(fieldType, field);
                System.out.println("注解的属性 fieldName = " + fieldName);
                System.out.println("注解的属性 fieldType = " + fieldType);
            }
        }
        int num = 0;
        for (String key : fieldMap.keySet()) {
            num++;
            fieldMap.get(key).set(dto, "dto1:" + key + num);
            fieldMap.get(key).set(dto2, "dto2:" + key + num);
        }
        list.add(dto);
        return list;
    }