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1、HttpComponents項(xiàng)目的介紹
先介紹一下一個開源項(xiàng)目， 這個項(xiàng)目就是Apache開源組織中的HttpComponents，主要是提供對http服務(wù)器的訪問功能，目前已經(jīng)是一個單獨(dú)的項(xiàng)目，可見http服務(wù)器的訪問絕非易事。 在某些時候可能需要通過程序來訪問這別人的網(wǎng)頁程序，比如從別人的網(wǎng)頁中“偷”一些數(shù)據(jù)。如果對方僅僅是一個很簡單的頁面，那我們的程序會很簡單，。但是考慮到一些服務(wù)授權(quán)的問 題，很多公司提供的頁面往往并不是可以通過一個簡單的URL就可以訪問的，而必須經(jīng)過注冊然后登錄后方可使用提供服務(wù)的頁面，這個時候就涉及到 COOKIE問題的處理。我們知道目前流行的動態(tài)網(wǎng)頁技術(shù)例如ASP、JSP無不是通過COOKIE來處理會話信息的。為了使我們的程序能使用別人所提供的服務(wù)頁面，就要求程序首先登錄后再訪問服務(wù)頁面！再比如通過HTTP來上傳文件呢？ HttpComponents項(xiàng)目就是專門設(shè)計(jì)來簡化HTTP客戶端與服務(wù)器進(jìn)行各種通訊編程。通過它可以讓原來很頭疼的事情現(xiàn)在輕松的解決，例如你不再管是HTTP或者HTTPS的通訊方式，告訴它你想使用HTTPS方式，剩下的事情交給 httpclient替你完成。 網(wǎng)址：http://www./ 主頁下面的Projects 可以找到HttpComponents項(xiàng)目，下載到相應(yīng)的jar包，以及源代碼跟示例程序。
2、httpcomponents 4.5.2 簡單使用
HttpComponents 也就是以前的httpclient項(xiàng)目，可以用來提供高效的、最新的、功能豐富的支持 HTTP 協(xié)議的客戶端/服務(wù)器編程工具包，并且它支持 HTTP 協(xié)議最新的版本和建議。不過現(xiàn)在的 HttpComponents 包含多個子項(xiàng)目，有： <dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.2</version>
</dependency>
get請求獲取響應(yīng)
CloseableHttpClient httpClient= HttpClients.createDefault();
HttpGet httpget = new HttpGet('http://www.baidu.com');
CloseableHttpResponse response = httpClient.execute(httpget);
HttpEntity httpEntity= response.getEntity();
String strResult= EntityUtils.toString(httpEntity); post請求獲取響應(yīng)
HttpPost httpost = new HttpPost('https://www.baidu.com');
List <NameValuePair> nvps = new ArrayList <NameValuePair>();
nvps.add(new BasicNameValuePair('IDToken1', 'username'));
nvps.add(new BasicNameValuePair('IDToken2', 'password'));
httpost.setEntity(new UrlEncodedFormEntity(nvps, Consts.UTF_8));
HttpClient提供URIBuilder工具類來簡化URIs的創(chuàng)建和修改過程。
URI uri = new URIBuilder()
.setScheme('http')
.setHost('www.google.com')
.setPath('/search')
.setParameter('q', 'httpclient')
.setParameter('btnG', 'Google Search')
.setParameter('aq', 'f')
.setParameter('oq', '')
.build();
HttpGet httpget = new HttpGet(uri);
System.out.println(httpget.getURI()) 模擬瀏覽器請求httpget.setHeader('User-Agent', 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0');
3、HttpComponents之httpclient基本使用方法 - httpclient的版本是4.3 A、第一種方式
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class HttpClient2 {
public static void main(String args[]) throws IOException {
List<NameValuePair> formparams = new ArrayList<NameValuePair>();
formparams.add(new BasicNameValuePair('account', ''));
formparams.add(new BasicNameValuePair('password', ''));
HttpEntity reqEntity = new UrlEncodedFormEntity(formparams, 'utf-8');
RequestConfig requestConfig = RequestConfig.custom()
.setSocketTimeout(5000)
.setConnectTimeout(5000)
.setConnectionRequestTimeout(5000)
.build();
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost('http:///login');
post.setEntity(reqEntity);
post.setConfig(requestConfig);
HttpResponse response = client.execute(post);
if (response.getStatusLine().getStatusCode() == 200) {
HttpEntity resEntity = response.getEntity();
String message = EntityUtils.toString(resEntity, 'utf-8');
System.out.println(message);
} else {
System.out.println('請求失敗');
}
}
} B、第二種方式，這種方式是用了一個http的連接池，同時使用httpbuilder構(gòu)造合適的http方法。 import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.client.methods.RequestBuilder;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import java.io.IOException;
import java.util.*;
public class HttpClientUtils {
private static PoolingHttpClientConnectionManager connectionManager = null;
private static HttpClientBuilder httpBulder = null;
private static RequestConfig requestConfig = null;
private static int MAXCONNECTION = 10;
private static int DEFAULTMAXCONNECTION = 5;
private static String IP = '';
private static int PORT = 80;
static {
//設(shè)置http的狀態(tài)參數(shù)
requestConfig = RequestConfig.custom()
.setSocketTimeout(5000)
.setConnectTimeout(5000)
.setConnectionRequestTimeout(5000)
.build();
HttpHost target = new HttpHost(IP, PORT);
connectionManager = new PoolingHttpClientConnectionManager();
connectionManager.setMaxTotal(MAXCONNECTION);
connectionManager.setDefaultMaxPerRoute(DEFAULTMAXCONNECTION);
connectionManager.setMaxPerRoute(new HttpRoute(target), 20);
httpBulder = HttpClients.custom();
httpBulder.setConnectionManager(connectionManager);
}
public static CloseableHttpClient getConnection() {
CloseableHttpClient httpClient = httpBulder.build();
httpClient = httpBulder.build();
return httpClient;
}
public static HttpUriRequest getRequestMethod(Map<String, String> map, String url, String method) {
List<NameValuePair> params = new ArrayList<NameValuePair>();
Set<Map.Entry<String, String>> entrySet = map.entrySet();
for (Map.Entry<String, String> e : entrySet) {
String name = e.getKey();
String value = e.getValue();
NameValuePair pair = new BasicNameValuePair(name, value);
params.add(pair);
}
HttpUriRequest reqMethod = null;
if ('post'.equals(method)) {
reqMethod = RequestBuilder.post().setUri(url)
.addParameters(params.toArray(new BasicNameValuePair[params.size()]))
.setConfig(requestConfig).build();
} else if ('get'.equals(method)) {
reqMethod = RequestBuilder.get().setUri(url)
.addParameters(params.toArray(new BasicNameValuePair[params.size()]))
.setConfig(requestConfig).build();
}
return reqMethod;
}
public static void main(String args[]) throws IOException {
Map<String, String> map = new HashMap<String, String>();
map.put('account', '');
map.put('password', '');
HttpClient client = getConnection();
HttpUriRequest post = getRequestMethod(map, 'http:///login', 'post');
HttpResponse response = client.execute(post);
if (response.getStatusLine().getStatusCode() == 200) {
HttpEntity entity = response.getEntity();
String message = EntityUtils.toString(entity, 'utf-8');
System.out.println(message);
} else {
System.out.println('請求失敗');
}
}
} =============END============= |
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