1.maven依赖：
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.6</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.2</version>
</dependency>>2.HttpClientUtil工具类
import java.io.IOException;
import java.io.InterruptedIOException;
import java.io.UnsupportedEncodingException;
import java.net.SocketTimeoutException;
import java.net.URLEncoder;
import java.net.UnknownHostException;
import java.nio.charset.Charset;
import java.security.NoSuchAlgorithmException;
import java.util.Map;
import java.util.Map.Entry;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLHandshakeException;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpRequest;
import org.apache.http.NoHttpResponseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.config.SocketConfig;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.util.EntityUtils;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
/**
*
* @author Qian Wenjin
*
*/
public class HttpClientUtil {
private static final Logger LOG = LogManager.getLogger(HttpClientUtil.class);
private static final int CONNECT_TIMEOUT = 5000;//设置超时毫秒数
private static final int SOCKET_TIMEOUT = 10000;//设置传输毫秒数
private static final int REQUESTCONNECT_TIMEOUT = 3000;//获取请求超时毫秒数
private static final int CONNECT_TOTAL = 200;//最大连接数
private static final int CONNECT_ROUTE = 20;//设置每个路由的基础连接数
private static final int VALIDATE_TIME = 30000;//设置重用连接时间
private static final String RESPONSE_CONTENT = "通信失败";
private static PoolingHttpClientConnectionManager manager = null;
private static CloseableHttpClient client = null;
static {
ConnectionSocketFactory csf = PlainConnectionSocketFactory.getSocketFactory();
LayeredConnectionSocketFactory lsf = createSSLConnSocketFactory();
Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
.register("http", csf).register("https", lsf).build();
manager = new PoolingHttpClientConnectionManager(registry);
manager.setMaxTotal(CONNECT_TOTAL);
manager.setDefaultMaxPerRoute(CONNECT_ROUTE);
manager.setValidateAfterInactivity(VALIDATE_TIME);
SocketConfig config = SocketConfig.custom().setSoTimeout(SOCKET_TIMEOUT).build();
manager.setDefaultSocketConfig(config);
RequestConfig requestConf = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT)
.setConnectionRequestTimeout(REQUESTCONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
client = HttpClients.custom().setConnectionManager(manager).setDefaultRequestConfig(requestConf).setRetryHandler(
//实现了HttpRequestRetryHandler接口的
//public boolean retryRequest(IOException exception, int executionCount, HttpContext context)方法
(exception, executionCount, context) -> {
if(executionCount >= 3)
return false;
if(exception instanceof NoHttpResponseException)//如果服务器断掉了连接那么重试
return true;
if(exception instanceof SSLHandshakeException)//不重试握手异常
return false;
if(exception instanceof InterruptedIOException)//IO传输中断重试
return true;
if(exception instanceof UnknownHostException)//未知服务器
return false;
if(exception instanceof ConnectTimeoutException)//超时就重试
return true;
if(exception instanceof SSLException)
return false;
HttpClientContext cliContext = HttpClientContext.adapt(context);
HttpRequest request = cliContext.getRequest();
if(!(request instanceof HttpEntityEnclosingRequest))
return true;
return false;
}).build();
if(manager!=null && manager.getTotalStats()!=null)
LOG.info("客户池状态："+manager.getTotalStats().toString());
}
private static SSLConnectionSocketFactory createSSLConnSocketFactory() {
SSLConnectionSocketFactory sslsf = null;
SSLContext context;
try {
context = SSLContext.getInstance(SSLConnectionSocketFactory.TLS);
sslsf = new SSLConnectionSocketFactory(context, NoopHostnameVerifier.INSTANCE);
} catch (NoSuchAlgorithmException e) {
LOG.error("SSL上下文创建失败，由于" + e.getLocalizedMessage());
e.printStackTrace();
}
return sslsf;
}
private String res(HttpRequestBase method) {
HttpClientContext context = HttpClientContext.create();
CloseableHttpResponse response = null;
String content = RESPONSE_CONTENT;
try {
response = client.execute(method, context);//执行GET/POST请求
HttpEntity entity = response.getEntity();//获取响应实体
if(entity!=null) {
Charset charset = ContentType.getOrDefault(entity).getCharset();
content = EntityUtils.toString(entity, charset);
EntityUtils.consume(entity);
}
} catch(ConnectTimeoutException cte) {
LOG.error("请求连接超时，由于 " + cte.getLocalizedMessage());
cte.printStackTrace();
} catch(SocketTimeoutException ste) {
LOG.error("请求通信超时，由于 " + ste.getLocalizedMessage());
ste.printStackTrace();
} catch(ClientProtocolException cpe) {
LOG.error("协议错误（比如构造HttpGet对象时传入协议不对(将'http'写成'htp')or响应内容不符合），由于 " + cpe.getLocalizedMessage());
cpe.printStackTrace();
} catch(IOException ie) {
LOG.error("实体转换异常或者网络异常， 由于 " + ie.getLocalizedMessage());
ie.printStackTrace();
} finally {
try {
if(response!=null) {
response.close();
}
} catch(IOException e) {
LOG.error("响应关闭异常， 由于 " + e.getLocalizedMessage());
}
if(method!=null) {
method.releaseConnection();
}
}
return content;
}
public String get(String url) {
HttpGet get = new HttpGet(url);
return res(get);
}
public String get(String url, String cookie) {
HttpGet get = new HttpGet(url);
if(StringUtils.isNotBlank(cookie))
get.addHeader("cookie", cookie);
return res(get);
}
public byte[] getAsByte(String url) {
return get(url).getBytes();
}
public String getHeaders(String url, String cookie, String headerName) {
HttpGet get = new HttpGet(url);
if(StringUtils.isNotBlank(cookie))
get.addHeader("cookie", cookie);
res(get);
Header[] headers = get.getHeaders(headerName);
return headers == null ? null : headers.toString();
}
public String getWithRealHeader(String url) {
HttpGet get = new HttpGet(url);
get.addHeader("Accept", "text/html,application/xhtml+xml,application/xml;");
get.addHeader("Accept-Language", "zh-cn");
get.addHeader("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.0.3) Gecko/2008092417 Firefox/3.0.3");
get.addHeader("Keep-Alive", "300");
get.addHeader("Connection", "Keep-Alive");
get.addHeader("Cache-Control", "no-cache");
return res(get);
}
public String post(String url, Map<String, String> param, String cookie) {
HttpPost post = new HttpPost(url);
param.keySet().stream().forEach(key -> {
String value = param.get(key);
if(value!=null)
post.addHeader(key, value);
});
if(StringUtils.isNotBlank(cookie))
post.addHeader("cookie", cookie);
return res(post);
}
public String post(String url, String data) {
HttpPost post = new HttpPost(url);
if(StringUtils.isNotBlank(data))
post.addHeader("Content-Type", "application/json");
post.setEntity(new StringEntity(data,ContentType.APPLICATION_JSON));
return res(post);
}
public String post(String url, Map<String, String> param, String cookie, Map<String, String> headers) {
HttpPost post = new HttpPost(url);
String reqEntity = "";
for(Entry<String, String> entry:param.entrySet()) {
post.addHeader(entry.getKey(), entry.getValue());
try {
reqEntity += entry.getKey() + "=" + URLEncoder.encode(entry.getValue(), "utf-8") + "&";
} catch (UnsupportedEncodingException e) {
LOG.error("请求实体转换异常，不支持的字符集，由于 " + e.getLocalizedMessage());
e.printStackTrace();
}
}
try {
post.setEntity(new StringEntity(reqEntity));
} catch (UnsupportedEncodingException e) {
LOG.error("请求设置实体异常，不支持的字符集， 由于 " + e.getLocalizedMessage());
e.printStackTrace();
}
if(StringUtils.isNotEmpty(cookie))
post.addHeader("cookie", cookie);
return res(post);
}
}
3.参考资料：
HttpClient工具类 ——人生若只如初见
4.注意，jdk版本要求1.8以上
ok~