Java爬虫实战指南：按关键字搜索淘宝商品

原创于 2025-07-09 10:58:30 发布 · 621 阅读

3 ·

CC 4.0 BY-SA版权

文章标签：

#java #爬虫 #开发语言

在电商数据分析、市场调研等领域，获取淘宝商品信息是一项常见需求。Java 语言凭借其强大的网络编程能力和丰富的库支持，成为实现此类爬虫的理想选择。本文将详细介绍如何使用 Java 爬虫按关键字搜索淘宝商品，并提供完整的代码示例。

一、准备工作

1. 注册淘宝开放平台账号

在使用淘宝 API 之前，需要在淘宝开放平台注册账号并创建应用。注册完成后，平台会分配一个 App Key 和 App Secret，这两个参数是调用 API 时的身份验证凭证。

2. 添加 Maven 依赖

为了方便地发送 HTTP 请求和解析 JSON 数据，我们需要在项目中添加以下 Maven 依赖：

xml

<dependencies>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.13</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.10.0</version>
    </dependency>
</dependencies>

二、代码实现

1. 发送 HTTP 请求

使用 HttpClient 发送 GET 请求，调用淘宝的商品搜索接口：

java

import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.security.MessageDigest;
import java.util.HashMap;
import java.util.Map;

public class TaobaoProductSearchCrawler {
    public static String searchTaobaoProducts(String appKey, String appSecret, String keyword, int page) {
        String timestamp = String.valueOf(System.currentTimeMillis() / 1000);
        Map<String, String> params = new HashMap<>();
        params.put("method", "taobao.item.search");
        params.put("app_key", appKey);
        params.put("timestamp", timestamp);
        params.put("v", "2.0");
        params.put("keyword", keyword);
        params.put("page", String.valueOf(page));
        params.put("sign_method", "md5");
        params.put("sign", generateSignature(appKey, appSecret, timestamp, params));

        try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
            HttpGet request = new HttpGet("https://gw.api.taobao.com/router.json?" + toQueryString(params));
            return EntityUtils.toString(httpClient.execute(request).getEntity());
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String generateSignature(String appKey, String appSecret, String timestamp, Map<String, String> params) {
        StringBuilder signStr = new StringBuilder(appKey + timestamp + appSecret);
        for (Map.Entry<String, String> entry : params.entrySet()) {
            signStr.append(entry.getKey()).append(entry.getValue());
        }
        return md5(signStr.toString());
    }

    public static String md5(String input) {
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            byte[] messageDigest = md.digest(input.getBytes());
            BigInteger no = new BigInteger(1, messageDigest);
            String hashtext = no.toString(16);
            while (hashtext.length() < 32) {
                hashtext = "0" + hashtext;
            }
            return hashtext;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static String toQueryString(Map<String, String> params) {
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, String> entry : params.entrySet()) {
            if (sb.length() > 0) {
                sb.append("&");
            }
            sb.append(entry.getKey()).append("=").append(entry.getValue());
        }
        return sb.toString();
    }
}

2. 解析 JSON 响应

使用 Jackson 库解析返回的 JSON 数据，提取商品信息：

java

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

public class Main {
    public static void main(String[] args) {
        String appKey = "your_app_key";
        String appSecret = "your_app_secret";
        String keyword = "iPhone 13";
        int page = 1;
        String response = TaobaoProductSearchCrawler.searchTaobaoProducts(appKey, appSecret, keyword, page);
        if (response != null) {
            parseResponse(response);
        }
    }

    public static void parseResponse(String jsonResponse) {
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            JsonNode rootNode = objectMapper.readTree(jsonResponse);
            int code = rootNode.path("code").asInt();
            String errorMessage = rootNode.path("errorMessage").asText();
            if (code == 0) {
                JsonNode itemsNode = rootNode.path("item_search_response").path("items");
                for (JsonNode itemNode : itemsNode) {
                    String title = itemNode.path("title").asText();
                    String price = itemNode.path("price").asText();
                    String picUrl = itemNode.path("pic_url").asText();
                    String detailUrl = itemNode.path("detail_url").asText();
                    System.out.println("商品标题: " + title);
                    System.out.println("商品价格: " + price);
                    System.out.println("商品图片: " + picUrl);
                    System.out.println("商品详情页 URL: " + detailUrl);
                }
            } else {
                System.out.println("API 请求失败，错误信息: " + errorMessage);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}