Sentinel Apache Httpclient 适配器介绍

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}

DefaultApacheHttpClientResourceExtractor

SentinelApacheHttpClientBuilder

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);
    }
}