添加以下依赖项pom.xml（如果您使用的是 Maven）：
<dependency> <groupId>com.alibaba.csp</groupId> <artifactId>sentinel-apache-httpclient-adapter</artifactId> <version>x.y.z</version> </dependency>
我们可以在初始化SentinelApacheHttpClientBuilder时使用when CloseableHttpClient，例如：
CloseableHttpClient httpclient = new SentinelApacheHttpClientBuilder().build();
如果我们要添加一些额外的配置，可以参考下面的代码
HttpClientBuilder builder = new SentinelApacheHttpClientBuilder(); //builder Other Definitions CloseableHttpClient httpclient = builder.build();
配置
SentinelApacheHttpClientConfig配置：
| 名称 | 描述 | 类型 | 默认值 |
| 字首 | 自定义资源前缀 | String |
httpclient: |
| 提取器 | 自定义资源提取器 | ApacheHttpClientResourceExtractor |
DefaultApacheHttpClientResourceExtractor |
| 倒退 | 当请求被阻塞时处理请求 | ApacheHttpClientFallback |
DefaultApacheHttpClientFallback |
提取器（资源提取器）
我们可以在默认配置中定义ApacheHttpClientResourceExtractor自定义资源提取器替换，例如： httpclient:GET:/httpclient/back/1 ==> httpclient:GET:/httpclient/back/{id}DefaultApacheHttpClientResourceExtractorSentinelApacheHttpClientBuilder
SentinelApacheHttpClientConfig config = new SentinelApacheHttpClientConfig(); config.setExtractor(new ApacheHttpClientResourceExtractor() { @Override public String extractor(HttpRequestWrapper request) { String contains = "/httpclient/back/"; String uri = request.getRequestLine().getUri(); if (uri.startsWith(contains)) { uri = uri.substring(0, uri.indexOf(contains) + contains.length()) + "{id}"; } return request.getMethod() + ":" + uri; } }); CloseableHttpClient httpclient = new SentinelApacheHttpClientBuilder(config).build();
回退（块处理）
我们可以ApacheHttpClientFallback在SentinelApacheHttpClientBuilder默认配置中定义，根据实际场景来处理请求被阻塞，例如：
public class DefaultApacheHttpClientFallback implements ApacheHttpClientFallback { @Override public CloseableHttpResponse handle(HttpRequestWrapper request, BlockException e) { // Just wrap and throw the exception. throw new SentinelRpcException(e); } }
