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Java爬虫如何解析返回的JSON数据？

article 2025/3/31 10:50:26

在Java中解析JSON数据通常使用一些流行的库，如Jackson或Gson。这些库提供了强大的功能，可以轻松地将JSON字符串转换为Java对象，或者从Java对象生成JSON字符串。以下是如何使用Jackson库解析返回的JSON数据的详细步骤和示例。

一、添加依赖

首先，确保你的项目中已经添加了Jackson库的依赖。如果你使用Maven，可以在pom.xml文件中添加以下依赖：

xml

<dependencies>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.10.0</version>
    </dependency>
</dependencies>

二、定义Java类

根据返回的JSON数据结构，定义相应的Java类。假设返回的JSON数据结构如下：

JSON

{
    "code": 200,
    "message": "success",
    "data": {
        "products": [
            {
                "id": "12345",
                "name": "商品名称",
                "price": "100.00",
                "description": "商品描述",
                "imageUrl": "https://example.com/image.jpg",
                "link": "https://1688.com/product/12345"
            }
        ]
    }
}

定义相应的Java类：

java

import java.util.List;

public class ApiResponse {
    private int code;
    private String message;
    private Data data;

    // Getters and Setters
    public int getCode() { return code; }
    public void setCode(int code) { this.code = code; }
    public String getMessage() { return message; }
    public void setMessage(String message) { this.message = message; }
    public Data getData() { return data; }
    public void setData(Data data) { this.data = data; }

    public static class Data {
        private List<Product> products;

        // Getters and Setters
        public List<Product> getProducts() { return products; }
        public void setProducts(List<Product> products) { this.products = products; }
    }

    public static class Product {
        private String id;
        private String name;
        private String price;
        private String description;
        private String imageUrl;
        private String link;

        // Getters and Setters
        public String getId() { return id; }
        public void setId(String id) { this.id = id; }
        public String getName() { return name; }
        public void setName(String name) { this.name = name; }
        public String getPrice() { return price; }
        public void setPrice(String price) { this.price = price; }
        public String getDescription() { return description; }
        public void setDescription(String description) { this.description = description; }
        public String getImageUrl() { return imageUrl; }
        public void setImageUrl(String imageUrl) { this.imageUrl = imageUrl; }
        public String getLink() { return link; }
        public void setLink(String link) { this.link = link; }
    }
}

三、解析JSON数据

使用Jackson库解析JSON数据，并将其转换为Java对象：

java

import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;

public class JsonParser {
    public static void main(String[] args) {
        String jsonResponse = "{"
                + "\"code\": 200,"
                + "\"message\": \"success\","
                + "\"data\": {"
                + "    \"products\": ["
                + "        {"
                + "            \"id\": \"12345\","
                + "            \"name\": \"商品名称\","
                + "            \"price\": \"100.00\","
                + "            \"description\": \"商品描述\","
                + "            \"imageUrl\": \"https://example.com/image.jpg\","
                + "            \"link\": \"https://1688.com/product/12345\""
                + "        }"
                + "    ]"
                + "}"
                + "}";

        ObjectMapper objectMapper = new ObjectMapper();
        try {
            ApiResponse response = objectMapper.readValue(jsonResponse, ApiResponse.class);
            if (response.getCode() == 200) {
                List<ApiResponse.Data.Product> products = response.getData().getProducts();
                for (ApiResponse.Data.Product product : products) {
                    System.out.println("商品ID: " + product.getId());
                    System.out.println("商品名称: " + product.getName());
                    System.out.println("商品价格: " + product.getPrice());
                    System.out.println("商品描述: " + product.getDescription());
                    System.out.println("商品图片URL: " + product.getImageUrl());
                    System.out.println("商品链接: " + product.getLink());
                    System.out.println("----------");
                }
            } else {
                System.out.println("API请求失败: " + response.getMessage());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}