在setProxy()方法中设置代理IP后可以将url中的域名换成这个代理IP。
http很简单，但是https这样会报错。
问题：如何使用代理发送https请求？
客户端发送https请求之前会先向这台服务器请求ssl证书，并在客服端对这个证书做一个校验。
而使用代理IP时，实际上请求打到了这个代理IP上，而客户端并不知道这件事，他仍然在等待url域名中所对应的ssl证书，而这代理ip对应的服务器实际上并没有这个证书，导致了https请求失败。
解决方法：
HttpClient中有一个 类，里面的方法中包含了需要验证的所有ssl证书类型，而我们只需要重写这个方法，并把需要验证的证书设置为空，即命令客户端不验证任何ssl证书，就ok了。
关于http请求头中的host字段：
https://blog.csdn.net/yzpbright/article/details/51052008
代码：
private JSONObject HttpPing(String dns, String uri, String qlb, String scheme) {
String url = scheme + "://" + dns + uri;
CloseableHttpClient httpclient = null;
if (scheme.equals("http")) {
httpclient = getHttpClient(qlb);
} else if (scheme.equals("https")) {
httpclient = getHttpsClient(qlb);
} else{
return null;
}
HttpGet httpGet = new HttpGet(url);
CloseableHttpResponse httpResp = null;
try {
httpResp = httpclient.execute(httpGet);
} catch (IOException e) {
e.printStackTrace();
}
try {
int statusCode = httpResp.getStatusLine().getStatusCode();
if (statusCode == org.apache.http.HttpStatus.SC_OK) {
return JSONObject.parseObject(EntityUtils.toString(httpResp.getEntity(), "UTF-8"));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
httpResp.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
private CloseableHttpClient getHttpClient(String qlb) {
HttpHost proxy = new HttpHost(qlb, 80, "http");
//把代理设置到请求配置
RequestConfig defaultRequestConfig = RequestConfig.custom()
.setProxy(proxy)
.build();
CloseableHttpClient httpclient = HttpClients.custom().setDefaultRequestConfig(defaultRequestConfig).build();
return httpclient;
}
private CloseableHttpClient getHttpsClient(String qlb) {
//这里设置客户端不检测服务器ssl证书
try {
X509TrustManager x509mgr = new X509TrustManager() {
public void checkClientTrusted(X509Certificate[] xcs, String string) {
}
public void checkServerTrusted(X509Certificate[] xcs, String string) {
}
public X509Certificate[] getAcceptedIssuers() {
return null;
}
};
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, new TrustManager[] { x509mgr }, null);
SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, SSLConnectionSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
HttpHost proxy = new HttpHost(qlb, 443, "https");
RequestConfig defaultRequestConfig = RequestConfig.custom()
.setProxy(proxy)
.build();
CloseableHttpClient httpclient = HttpClients.custom().setSSLSocketFactory(sslsf).setDefaultRequestConfig(defaultRequestConfig).build();
return httpclient;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}