fastJson Java对象转JSON，JSON转Java对象

fastJson依赖：

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.70</version>
        </dependency>

Java集合转JSON，JSON转Java集合：

        List<Object> objectList = new ArrayList<>();
        for(int i=0; i<10; i++) {
            Product product = new Product();
            product.setProductId(1l);
            product.setProductName("破军" + i);
            product.setProductNum(i);
            product.setProductPrice(3000d);
            objectList.add(product);
        }

        String jsonString = JSON.toJSONString(objectList);
        System.out.println("json: " + jsonString);

        List<Product> products = JSONObject.parseArray(jsonString, Product.class);
        for (Product product : products) {
            System.out.println(product.toString());
        }

Java对象转JSON，JSON转Java对象：

        Product product = new Product();
        product.setProductId(1l);
        product.setProductName("金箍棒");
        product.setProductNum(1);
        product.setProductPrice(10800d);
        byte[] bytes = JSON.toJSONString(product).getBytes();

        String jsonString1 = new String(bytes, "UTF-8");
        Product newProduct = JSONObject.parseObject(jsonString1, Product.class);
        System.out.println(newProduct.toString());

        JSONObject jsonObject = new JSONObject();
        jsonObject.put("name", "tom");
        jsonObject.put("age", 23);
        String jsonString = JSON.toJSONString(jsonObject);
        System.out.println(jsonString);