下面给出一份可直接落地的「Java 版 1688 商品详情 API 爬虫」完整示例，覆盖签名算法、HTTP 调用、JSON 解析、异常重试、频率控制等关键要点，复制即可运行。
（注：1688 接口需企业认证并申请 AppKey / AppSecret，以下代码以官方 REST 网关item_get为例，也可平替为第三方代理网关，只需换域名即可 。）
一、Maven 依赖
<dependencies> <!-- HTTP --> <dependency> <groupId>org.apache.httpcomponents.client5</groupId> <artifactId>httpclient5</artifactId> <version>5.3.1</version> </dependency> <!-- JSON --> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.17.0</version> </dependency> </dependencies>二、签名工具（1688 官方 MD5 签名规则）
public class SignUtil { public static String sign(TreeMap<String, String> params, String appSecret) { StringBuilder sb = new StringBuilder(appSecret); for (Map.Entry<String, String> e : params.entrySet()) { sb.append(e.getKey()).append(e.getValue()); } sb.append(appSecret); return md5(sb.toString()).toUpperCase(); } private static String md5(String raw) { try { byte[] bs = MessageDigest.getInstance("MD5").digest(raw.getBytes(StandardCharsets.UTF_8)); StringBuilder hex = new StringBuilder(); for (byte b : bs) hex.append(String.format("%02X", b & 0xFF)); return hex.toString(); } catch (Exception e) { throw new RuntimeException(e); } } }三、统一入口 ——ItemGetService
public class ItemGetService { private static final String GATEWAY = "https://api.1688.com/router/rest"; private final String appKey; private final String appSecret; private final CloseableHttpClient http; public ItemGetService(String appKey, String appSecret) { this.appKey = appKey; this.appSecret = appSecret; this.http = HttpClients.custom() .setConnectionManager(PoolingHttpClientConnectionManagerBuilder.create() .setMaxConnTotal(50).setMaxConnPerRoute(10).build()) .build(); } /** 获取商品详情（自动重试 3 次） */ public ItemDO getItem(long numIid) throws IOException { TreeMap<String, String> params = new TreeMap<>(); params.put("method", "item_get"); params.put("app_key", appKey); params.put("timestamp", String.valueOf(System.currentTimeMillis())); params.put("num_iid", String.valueOf(numIid)); params.put("v", "2.0"); params.put("sign_method", "md5"); params.put("format", "json"); params.put("sign", SignUtil.sign(params, appSecret)); String url = GATEWAY + "?" + URLEncodedUtils.format( params.entrySet().stream() .map(e -> new BasicNameValuePair(e.getKey(), e.getValue())) .collect(Collectors.toList()), StandardCharsets.UTF_8); for (int i = 0; i < 3; i++) { try (CloseableHttpResponse resp = http.execute(new HttpGet(url))) { if (resp.getCode() == 200) { JsonNode root = new ObjectMapper().readTree(EntityUtils.toString(resp.getEntity())); if ("0".equals(root.get("code").asText())) { return new ObjectMapper().convertValue(root.get("item"), ItemDO.class); } throw new IllegalStateException("API 业务错误: " + root.get("msg").asText()); } } catch (Exception e) { if (i == 2) throw e; try { Thread.sleep(1000); } catch (InterruptedException ignore) {} } } throw new RuntimeException("重试 3 次仍失败"); } @Data // lombok public static class ItemDO { private String title; private BigDecimal price; private Integer num; // 库存 private String picUrl; private List<Sku> skus; } public void shutdown() throws IOException { http.close(); } }四、频率控制 + 批量调用示例
public class CrawlerBoot { public static void main(String[] args) throws Exception { ItemGetService api = new ItemGetService("你的AppKey", "你的AppSecret"); List<Long> numIids = List.of(610947572360L, 623456789012L); // 商品ID池 for (Long id : numIids) { ItemGetService.ItemDO item = api.getItem(id); System.out.printf("标题=%s 价格=%s 库存=%d%n", item.getTitle(), item.getPrice(), item.getNum()); Thread.sleep(350); // 约 3 次/秒，低于官方 5 次/秒限制 } api.shutdown(); } }五、常见坑 & 优化建议
签名顺序必须
TreeMap升序，否则 4005 授权失败。免费账号每日调用上限 1 万次，超出需购买套餐；峰值时段做好限流与重试。
如需 SKU 图、阶梯价、近 30 天销量，需在参数额外指定
fields=skus,priceRange,saleInfo。若走第三方代理网关（如
api-gw.onebound.cn），签名规则不变，仅换域名即可。数据落库时建议用
ON DUPLICATE KEY UPDATE做幂等，避免重复写入。
六、一句话总结
以上代码即为“Java 爬虫 1688 详情 API 接口”的最小可运行骨架，已帮你屏蔽掉签名、编码、重试、频率等所有细节，直接填上自己的 AppKey / Secret 即可把 1688 商品库变成本地数据表
