android 获取 json数据 获取json值

通常我们在做接口开发时，常常需要接受json类型的数据，如需要先使用postMian进行测试，就需要大量的写json，这样通常需要耗费很长时间，所以本人就写了一个工具类。

//3、获取json请求参数
    public static String toParam(Class clazz) {
        try {
            Object instance = clazz.newInstance();
            Class<?> aClass = instance.getClass();
            Field[] fields = copyField(aClass);//数据不可为一个死循环(继承时有可能发生)
            for (Field field : fields) {
                setFieldObj(field, instance);
                setField(field, instance);
            }
            ObjectMapper mapper = new ObjectMapper();
            return mapper.writeValueAsString(instance);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

public static void setFieldObj(Field field, Object instance) throws Exception {
        field.setAccessible(true);
        if (validType(field.getType())) {
            Class<?> type = (Class<?>) field.getGenericType();
            Object o = type.newInstance();
            Field[] fields1 = copyField(o.getClass());
            for (Field newField : fields1) {
                setFieldObj(newField, o);
                setField(newField, o);
            }
            field.set(instance, o);
            return;
        }
        if (field.getType().equals(List.class)) {
            ParameterizedType type = (ParameterizedType) field.getGenericType();
            Class<?> argument = (Class<?>) type.getActualTypeArguments()[0];
            ArrayList<Object> list = new ArrayList<>();
            list.add(argument.newInstance());
            for (Object o : list) {
                Field[] listField = copyField(o.getClass());
                for (Field field1 : listField) {
                    setFieldObj(field1, o);
                    setField(field1, o);
                }
            }
            field.set(instance, list);
            return;
        }
        if (field.getType().equals(Map.class) || field.getType().equals(HashMap.class)) {
            ParameterizedType type = (ParameterizedType) field.getGenericType();
            field.set(instance, setMapVal((Class<?>) type.getActualTypeArguments()[1]));
            return;
        }
    }

public static HashMap setMapVal(Class<?> type) {
        HashMap<String, Object> map = new HashMap<>();
        if (type.equals(Integer.class)) {
            map.put(Symbol.KEY, 0);
            return map;
        }
        if (type.equals(Double.class)) {
            map.put(Symbol.KEY, 0d);
            return map;
        }
        if (type.equals(Float.class)) {
            map.put(Symbol.KEY, 0f);
            return map;
        }
        if (type.equals(String.class)) {
            map.put(Symbol.KEY, "");
            return map;
        }
        map.put(Symbol.KEY,null);
        return map;
    }

public static void setField(Field field, Object instance) throws Exception {
        field.setAccessible(true);
        if (field.getType().equals(String.class)) {
            field.set(instance, "");
            return;
        }
        if (field.getType().equals(Integer.class) || field.getType().equals(int.class)) {
            field.set(instance, 0);
            return;
        }
        if (field.getType().equals(Date.class)) {
            field.set(instance, null);
            return;
        }
    }

//判断是否为包装类型
    public static boolean validType(Class<?> type) {
        if (type.equals(String.class) || type.equals(Set.class)) {
            return false;
        } else if (type.equals(Integer.class) || type.equals(int.class)) {
            return false;
        } else if (type.equals(BigDecimal.class) || type.equals(Date.class)) {
            return false;
        } else if (type.equals(Double.class) || type.equals(double.class)) {
            return false;
        } else if (type.equals(Boolean.class) || type.equals(boolean.class)) {
            return false;
        } else if (type.equals(Byte.class) || type.equals(byte.class)) {
            return false;
        } else if (type.equals(Short.class) || type.equals(short.class)) {
            return false;
        } else if (type.equals(Char.class) || type.equals(char.class)) {
            return false;
        } else if (type.equals(List.class) || type.equals(Map.class)) {
            return false;
        }else if (type.equals(HashMap.class) || type.equals(HashSet.class)) {
            return false;
        }
        return true;
    }

测试

@Test
    public void  test006(){
        String s = BeanUtil.toParam(User2.class);
        System.out.println(s);
        //输出实例 {"id2":0,"name2":"","addr2":"","age":"","phone":""}
    }

输出实例 {"id2":0,"name2":"","addr2":"","age":"","phone":""}

备注：支持对象字段为list类型或map类型，对象类型都可以进行格式化。多层对象解析，单不可为死循环，切记