标签：java httpclient http协议
相对于httpurlconnection ，httpclient更加丰富，也更加强大，其中apache有两个项目都是httpclient，一个是commonts包下的，这个是通用的，更专业的是org.apache.http.包下的，所以我一般用后者；
httpclient可以处理长连接，保存会话，重连接，以及请求过滤器，连接重用等等...
下面是测试代码（全部总结来自官方文档，以及翻译）
须要下载核心包：httpclient-4.3.4.jar ，也可在官网下载：http://hc.apache.org/downloads.cgi
package httpClientTest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.InterruptedIOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.UnknownHostException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import javax.net.ssl.SSLException;
import org.apache.http.Consts;
import org.apache.http.HeaderElement;
import org.apache.http.HeaderElementIterator;
import org.apache.http.HttpClientConnection;
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
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.protocol.HttpClientContext;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.client.utils.URIUtils;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.ConnectionKeepAliveStrategy;
import org.apache.http.conn.ConnectionRequest;
import org.apache.http.conn.HttpClientConnectionManager;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.entity.ContentType;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultConnectionKeepAliveStrategy;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.client.LaxRedirectStrategy;
import org.apache.http.impl.conn.BasicHttpClientConnectionManager;
import org.apache.http.message.BasicHeaderElementIterator;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;
public class Main {
public static void main(String[] args) {
try {
test9();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 测试1： 构建复杂uri，这种方式会很方便的设置多个参数；
*
* HttpClients类是client的具体一个实现类；
*
* URIBuilder包含：协议，主机名，端口（可选），资源路径，和多个参数（可选）
*
*/
private static void test1() {
CloseableHttpClient client = HttpClients.createDefault();
URI uri = null;
try {
uri = new URIBuilder()
.setScheme("http")
.setHost("webservice.webxml.com.cn")
.setPath("/WebServices/MobileCodeWS.asmx/getDatabaseInfo")
.setParameter("", "")//这里可以设置多个参数
.setParameter("", "")
.setParameter("", "")
.setParameter("", "")
.build();
} catch (URISyntaxException e1) {
e1.printStackTrace();
}
//http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx/getDatabaseInfo
HttpGet get = new HttpGet(uri);
try {
CloseableHttpResponse response = client.execute(get);
if(response.getStatusLine().getStatusCode()==200){
System.out.println(EntityUtils.toString(response.getEntity()));
//以下这种方式读取流也可以，只不过用EntityUtils会更方便
/*InputStream is = response.getEntity().getContent();
ByteArrayOutputStream os = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len=-1;
while((len = is.read(buffer))!=-1){
os.write(buffer,0,len);
}
os.close();
is.close();
System.out.println(os.size()+new String(os.toByteArray(),"utf-8"));*/
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 为uri进行加密，并进行表单提交；
*
* 许多应用需要模拟提交的HTML表单的处理，例如，在
为了登录到Web应用程序或提交的输入数据。 HttpClient提供的实体类
UrlEncodedFormEntity可以实现该过程；
*/
private static void test2(){
CloseableHttpClient client = HttpClients.createDefault();
HttpPost httppost = new HttpPost("http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx/getMobileCodeInfo");
//构建请求参数
List<NameValuePair> list = new ArrayList<NameValuePair>();
list.add(new BasicNameValuePair("mobileCode", "110"));
list.add(new BasicNameValuePair("userID", ""));
//构建url加密实体，并以utf-8方式进行加密；
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, Consts.UTF_8);
httppost.setEntity(entity);
try {
CloseableHttpResponse response = client.execute(httppost);
if(response.getStatusLine().getStatusCode()==200){
//org.apache.http.util.EntityUtils类可以快速处理服务器返回实体对象
System.out.println(EntityUtils.toString(response.getEntity()));
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 以回调方式处理返回结果
*
* 处理响应的最简单和最方便的方法是通过使用ResponseHandler的
接口。用户不必担心连接管理的问题。当使用一个
ResponseHandler的时候，无论是否请求执行成功或导致异常，HttpClient将会自动释放连接。
*/
private static void test3(){
CloseableHttpClient client = HttpClients.createDefault();
//==============================================================
ResponseHandler<Object> handler = new ResponseHandler<Object>() {
@Override
public Object handleResponse(final HttpResponse response) throws IOException {
HttpEntity entity = response.getEntity();
if (entity == null) {
throw new ClientProtocolException("返回结果为空");
}
if(response.getStatusLine().getStatusCode()==200){
//获取返回结果的字符集 如：utf-8 gbk，并以这种字符集来读取流信息
ContentType contentType = ContentType.getOrDefault(entity);
Charset charset = contentType.getCharset();
InputStreamReader reader = new InputStreamReader(entity.getContent(), charset);
BufferedReader br = new BufferedReader(reader);
StringBuffer sb = new StringBuffer();
char[] buffer = new char[1024];
while (br.read(buffer)!=-1) {
sb.append(new String(buffer));
}
return sb.toString();
}
return null;
}
};
//===================================================================
URI uri = null;//构建uri实体
try {
uri = new URIBuilder()
.setScheme("http")
.setHost("webservice.webxml.com.cn")
.setPath("/WebServices/MobileCodeWS.asmx/getDatabaseInfo")
.setParameter("", "")
.setParameter("", "")
.setParameter("", "")
.build();
} catch (URISyntaxException e) {
e.printStackTrace();
}
HttpPost post = new HttpPost(uri);
try {
//handler回调
Object obj = client.execute(post, handler);
System.out.println("返回结果："+obj);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 设置长连接策略，根据服务器的约束或者客户端的约束来设置长连接的时长；
*/
private static void test4() {
ConnectionKeepAliveStrategy strategy = new DefaultConnectionKeepAliveStrategy() {
/**
* 服务器端配置（以tomcat为例）：keepAliveTimeout=60000，表示在60s内内，服务器会一直保持连接状态。
* 也就是说，如果客户端一直请求服务器，且间隔未超过60s，则该连接将一直保持，如果60s内未请求，则超时。
*
* getKeepAliveDuration返回超时时间；
*/
@Override
public long getKeepAliveDuration(HttpResponse response, HttpContext context) {
//如果服务器指定了超时时间，则以服务器的超时时间为准
HeaderElementIterator it = new BasicHeaderElementIterator(response.headerIterator(HTTP.CONN_KEEP_ALIVE));
while (it.hasNext()) {
HeaderElement he = it.nextElement();
String param = he.getName();
String value = he.getValue();
if (value != null && param.equalsIgnoreCase("timeout")) {
try {
System.out.println("服务器指定的超时时间：" + value + " 秒");
return Long.parseLong(value) * 1000;
} catch (NumberFormatException ignore) {
ignore.printStackTrace();
}
}
}
long keepAlive = super.getKeepAliveDuration(response, context);
// 如果服务器未指定超时时间，则客户端默认30s超时
if (keepAlive == -1) {
keepAlive = 30 * 1000;
}
return keepAlive;
/*如果访问webservice.webxml.com.cn主机，则超时时间5秒，其他主机超时时间30秒
HttpHost host = (HttpHost) context.getAttribute(HttpClientContext.HTTP_TARGET_HOST);
if ("webservice.webxml.com.cn".equalsIgnoreCase(host.getHostName())) {
keepAlive = 10 * 1000;
} else {
keepAlive = 30 * 1000;
}*/
}
};
CloseableHttpClient client = HttpClients.custom().setKeepAliveStrategy(strategy).build();
URI uri = null;//构建uri实体
try {
uri = new URIBuilder()
.setScheme("http")
.setHost("webservice.webxml.com.cn")
.setPath("/WebServices/MobileCodeWS.asmx/getDatabaseInfo")
.setParameter("", "")
.build();
} catch (URISyntaxException e) {
e.printStackTrace();
}
HttpPost post = new HttpPost(uri);
try {
CloseableHttpResponse response = client.execute(post);
if(response.getStatusLine().getStatusCode()==200){
String result = EntityUtils.toString(response.getEntity());
System.out.println("返回的结果====="+result);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 构建复杂请求体
*
* RequestConfig将会保存在context上下文中，并会在连续的请求中进行传播（来自官方文档）；
*
*/
private void test5(){
CloseableHttpClient client = HttpClients.createDefault();
//构建请求配置
RequestConfig config = RequestConfig.
custom().
setSocketTimeout(1000*10).
setConnectTimeout(1000*10).
build();
//==============================================================
ResponseHandler<Object> handler = new ResponseHandler<Object>() {//回调
@Override
public Object handleResponse(final HttpResponse response) throws IOException {
HttpEntity entity = response.getEntity();
if (entity == null) {
throw new ClientProtocolException( "返回结果为空");
}
if(response.getStatusLine().getStatusCode()==200){
ContentType contentType = ContentType.getOrDefault(entity);
Charset charset = contentType.getCharset();
InputStreamReader reader = new InputStreamReader(entity.getContent(), charset);
BufferedReader br = new BufferedReader(reader);
StringBuffer sb = new StringBuffer();
char[] buffer = new char[1024];
while (br.read(buffer)!=-1) {
sb.append(new String(buffer));
}
return sb.toString();
}
return null;
}
};
//===================================================================
URI uri = null;
try {
uri = new URIBuilder()
.setScheme("http")
.setHost("webservice.webxml.com.cn")
.setPath("/WebServices/MobileCodeWS.asmx/getDatabaseInfo")
.setParameter("", "")
.setParameter("", "")
.setParameter("", "")
.build();
} catch (URISyntaxException e) {
e.printStackTrace();
}
HttpPost post = new HttpPost(uri);
post.setConfig(config);//设置请求配置
try {
Object obj = client.execute(post, handler);
System.out.println("返回结果："+obj);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 异常恢复机制：
*
* HttpRequestRetryHandler连接失败后，可以针对相应的异常进行相应的处理措施；
* HttpRequestRetryHandler接口须要用户自己实现；
*
*/
private static void test6(){
HttpRequestRetryHandler retryHandler = new HttpRequestRetryHandler() {
/**
* exception异常信息；
* executionCount：重连次数；
* context：上下文
*/
@Override
public boolean retryRequest(IOException exception, int executionCount,HttpContext context) {
System.out.println("重连接次数："+executionCount);
if (executionCount >= 5) {//如果连接次数超过5次，就不进行重复连接
return false;
}
if (exception instanceof InterruptedIOException) {//io操作中断
return false;
}
if (exception instanceof UnknownHostException) {//未找到主机
// Unknown host
return false;
}
if (exception instanceof ConnectTimeoutException) {//连接超时
return true;
}
if (exception instanceof SSLException) {
// SSL handshake exception
return false;
}
HttpClientContext clientContext = HttpClientContext.adapt(context);
HttpRequest request = clientContext.getRequest();
boolean idempotent = !(request instanceof HttpEntityEnclosingRequest);
if (idempotent) {
// Retry if the request is considered idempotent
return true;
}
return false;
}
};
CloseableHttpClient client = HttpClients.custom().setRetryHandler(retryHandler).build();
RequestConfig config = RequestConfig.
custom().
setSocketTimeout(1000*10).
setConnectTimeout(1000*10).
build();
HttpPost post = new HttpPost("http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx/getDatabaseInfo");
post.setConfig(config);
try {
HttpResponse response = client.execute(post);
HttpEntity entity = response.getEntity();
ContentType contentType = ContentType.getOrDefault(entity);
Charset charset = contentType.getCharset();
InputStreamReader reader = new InputStreamReader(entity.getContent(), charset);
BufferedReader br = new BufferedReader(reader);
StringBuffer sb = new StringBuffer();
char[] buffer = new char[1024];
while (br.read(buffer) != -1) {
sb.append(new String(buffer));
}
System.out.println("返回的结果："+sb.toString());
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* HTTP请求过滤器，在执行请求之前拦截HttpRequest 和 HttpContext；
*/
private static void test7() throws ClientProtocolException, IOException{
HttpRequestInterceptor requestInterceptor = new HttpRequestInterceptor() {
/**
* 处理请求：
* 如果是客户端：这个处理在发送请求之前执行；
* 如果是服务器：这个处理在接收到请求体之前执行；
*/
public void process(final HttpRequest request, final HttpContext context) throws HttpException, IOException {
AtomicInteger count = (AtomicInteger) context.getAttribute("count");
request.addHeader("count", Integer.toString(count.getAndIncrement()));
}
};
CloseableHttpClient httpclient = HttpClients.
custom().
addInterceptorLast(requestInterceptor).
build();
AtomicInteger count = new AtomicInteger(1);
HttpClientContext context = HttpClientContext.create();
context.setAttribute("count", count);
HttpGet httpget = new HttpGet("http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx/getDatabaseInfo");
for (int i = 0; i < 10; i++) {
CloseableHttpResponse response = httpclient.execute(httpget,context);
try {
HttpEntity entity = response.getEntity();
// System.out.println(EntityUtils.toString(entity));
} finally {
response.close();
}
}
}
/**
*
* httpclient会自动处理重定向；
*
* 301 永久重定向,告诉客户端以后应从新地址访问.
302 作为HTTP1.0的标准,以前叫做Moved Temporarily ,现在叫Found. 现在使用只是为了兼容性的 处理,包括PHP的默认Location重定向用的也是302.
但是HTTP 1.1 有303 和307作为详细的补充,其实是对302的细化
303：对于POST请求，它表示请求已经被处理，客户端可以接着使用GET方法去请求Location里的URI。
307：对于POST请求，表示请求还没有被处理，客户端应该向Location里的URI重新发起POST请求。
*/
private static void test8() throws ClientProtocolException, IOException,
URISyntaxException {
LaxRedirectStrategy redirectStrategy = new LaxRedirectStrategy();
CloseableHttpClient httpclient = HttpClients.custom().setRedirectStrategy(redirectStrategy).build();
HttpClientContext context = HttpClientContext.create();
HttpGet httpget = new HttpGet("http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx/getDatabaseInfo");
CloseableHttpResponse response = httpclient.execute(httpget, context);
try {
HttpHost target = context.getTargetHost();
List<URI> redirectLocations = context.getRedirectLocations();
URI location = URIUtils.resolve(httpget.getURI(), target, redirectLocations);
System.out.println("Final HTTP location: " + location.toASCIIString());
} finally {
response.close();
}
}
}
JAVA: httpclient 详解；,布布扣,bubuko.com
标签：java httpclient http协议
原文地址：http://blog.csdn.net/lyc66666666666/article/details/36899463
