如何用RequestConfig替换不推荐使用的httpClient.getParams()？

Question

我继承了代码

import org.apache.http.client.HttpClient;
...
HttpClient httpclient = createHttpClientOrProxy();
...



private HttpClient createHttpClientOrProxy() {
    HttpClient httpclient = new DefaultHttpClient();

    /*
     * Set an HTTP proxy if it is specified in system properties.
     * 
     * http://docs.oracle.com/javase/6/docs/technotes/guides/net/proxies.html
     * http://hc.apache.org/httpcomponents-client-ga/httpclient/examples/org/apache/http/examples/client/ClientExecuteProxy.java
     */
    if( isSet(System.getProperty("http.proxyHost")) ) {
        int port = 80;
        if( isSet(System.getProperty("http.proxyPort")) ) {
            port = Integer.parseInt(System.getProperty("http.proxyPort"));
        }
        HttpHost proxy = new HttpHost(System.getProperty("http.proxyHost"), port, "http");
// @Deprecated methods here... getParams() and ConnRoutePNames
        httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);
    }
    return httpclient;
}

httpClient.getParams() 是@Deprecated并读"

HttpParams  getParams()
Deprecated. 
(4.3) use RequestConfig.

RequestConfig没有类文档,我不知道应该用什么方法替换getParams()和ConnRoutePNames.DEFAULT_PROXY.

Answer 1

这更像是@Stephane Lallemagne给出的答案的后续行动

有一种非常简洁的方法可以让HttpClient获取系统代理设置

CloseableHttpClient client = HttpClients.custom()
        .setRoutePlanner(
             new SystemDefaultRoutePlanner(ProxySelector.getDefault()))
        .build();

或者,如果您希望HttpClient实例完全配置系统默认值

CloseableHttpClient client = HttpClients.createSystem();

Answer 2

您正在使用apache HttpClient 4.3库与apache HttpClient 4.2代码.

请注意,getParams()和ConnRoutePNames不是您的案例中唯一不推荐使用的方法.DefaultHttpClient类本身依赖于4.2实现,并且在4.3中也不推荐使用.

关于这里的4.3文档(http://hc.apache.org/httpcomponents-client-4.3.x/tutorial/html/connmgmt.html#d5e473),您可以这样重写:

private HttpClient createHttpClientOrProxy() {

    HttpClientBuilder hcBuilder = HttpClients.custom();

    // Set HTTP proxy, if specified in system properties
    if( isSet(System.getProperty("http.proxyHost")) ) {
        int port = 80;
        if( isSet(System.getProperty("http.proxyPort")) ) {
            port = Integer.parseInt(System.getProperty("http.proxyPort"));
        }
        HttpHost proxy = new HttpHost(System.getProperty("http.proxyHost"), port, "http");
        DefaultProxyRoutePlanner routePlanner = new DefaultProxyRoutePlanner(proxy);
        hcBuilder.setRoutePlanner(routePlanner);
    }

    CloseableHttpClient httpClient = hcBuilder.build();

    return httpClient;
}