在工作中要用到android,然后进行网络请求的时候,打算使用httpClient。
总结一下httpClient的一些基本使用。
版本是4.2.2。
使用这个版本的过程中,百度很多,结果都是出现的org.apache.commons.httpclient.这个包名,而不是我这里的org.apache.http.client.HttpClient----------前者版本是Commons
HttpClient 3.x ,不是最新的版本HttpClient 4.×。
官网上面:
Commons HttpClient 3.x codeline is at the end of life. All users of Commons HttpClient 3.x are strongly encouraged to upgrade to HttpClient 4.1.
1.基本的get
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
public void getUrl(String url, String encoding)
throws ClientProtocolException, IOException {
// 默认的client类。
HttpClient client = new DefaultHttpClient();
// 设置为get取连接的方式.
HttpGet get = new HttpGet(url);
// 得到返回的response.
HttpResponse response = client.execute(get);
// 得到返回的client里面的实体对象信息.
HttpEntity entity = response.getEntity();
if (entity != null) {
System.out.println("内容编码是:" + entity.getContentEncoding());
System.out.println("内容类型是:" + entity.getContentType());
// 得到返回的主体内容.
InputStream instream = entity.getContent();
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(instream, encoding));
System.out.println(reader.readLine());
} catch (Exception e) {
e.printStackTrace();
} finally {
instream.close();
}
}
// 关闭连接.
client.getConnectionManager().shutdown();
}
2.基本的Post
下面的params参数,是在表单里面提交的参数。
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
public void postUrlWithParams(String url, Map params, String encoding)
throws Exception {
DefaultHttpClient httpclient = new DefaultHttpClient();
try {
HttpPost httpost = new HttpPost(url);
// 添加参数
List<NameValuePair> nvps = new ArrayList<NameValuePair>();
if (params != null && params.keySet().size() >0) {
Iterator iterator = params.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry entry = (Entry) iterator.next();
nvps.add(new BasicNameValuePair((String) entry.getKey(),
(String) entry.getValue()));
}
httpost.setEntity(new UrlEncodedFormEntity(nvps, Consts.UTF_8));
HttpResponse response = httpclient.execute(httpost);
HttpEntity entity = response.getEntity();
System.out.println("Login form get: " + response.getStatusLine()
+ entity.getContent());
dump(entity, encoding);
System.out.println("Post logon cookies:");
List<Cookie> cookies = httpclient.getCookieStore().getCookies();
if (cookies.isEmpty()) {
System.out.println("None");
} else {
for (int i =0; i < cookies.size(); i++) {
System.out.println("- " + cookies.get(i).toString());
} finally {
// 关闭请求
httpclient.getConnectionManager().shutdown();
3。打印页面输出的小代码片段
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
private staticvoid dump(HttpEntity entity, String encoding)
throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(
entity.getContent(), encoding));
System.out.println(br.readLine());
4.常见的登录session问题,需求:使用账户,密码登录系统之后,然后再访问页面不出错。
特别注意,下面的httpclient对象要使用一个,而不要在第二次访问的时候,重新new一个。至于如何保存这个第一步经过了验证的httpclient,有很多种方法实现。单例,系统全局变量(android 下面的Application),ThreadLocal变量等等。
以及下面创建的httpClient要使用ThreadSafeClientConnManager对象!
public String getSessionId(String url, Map params, String encoding,
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
String url2) throws Exception {
DefaultHttpClient httpclient = new DefaultHttpClient(
new ThreadSafeClientConnManager());
try {
HttpPost httpost = new HttpPost(url);
// 添加参数
List<NameValuePair> nvps = new ArrayList<NameValuePair>();
if (params != null && params.keySet().size() >0) {
Iterator iterator = params.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry entry = (Entry) iterator.next();
nvps.add(new BasicNameValuePair((String) entry.getKey(),
(String) entry.getValue()));
// 设置请求的编码格式
httpost.setEntity(new UrlEncodedFormEntity(nvps, Consts.UTF_8));
// 登录一遍
httpclient.execute(httpost);
// 然后再第二次请求普通的url即可。
httpost = new HttpPost(url2);
BasicResponseHandler responseHandler = new BasicResponseHandler();
System.out.println(httpclient.execute(httpost, responseHandler));
} finally {
// 关闭请求
httpclient.getConnectionManager().shutdown();
return "";
}
5.下载文件,例如mp3等等。
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
//第一个参数,网络连接;第二个参数,保存到本地文件的地址
public void getFile(String url, String fileName) {
HttpClient httpClient = new DefaultHttpClient();
ResponseHandler<byte[]> handler =new ResponseHandler<byte[]>() {
public byte[] handleResponse(HttpResponse response)
throws ClientProtocolException, IOException {
HttpEntity entity = response.getEntity();
if (entity !=
null) {
return EntityUtils.toByteArray(entity);
} else {
return
null;
}
};
byte[] charts = httpClient.execute(get, handler);
FileOutputStream out = new FileOutputStream(fileName);
out.write(charts);
out.close();
} catch (Exception e) {
e.printStackTrace();
httpClient.getConnectionManager().shutdown();
6.创建一个多线程环境下面可用的httpClient
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
HttpParams params = new BasicHttpParams();
//设置允许链接的做多链接数目
ConnManagerParams.setMaxTotalConnections(params, 200);
//设置超时时间.
ConnManagerParams.setTimeout(params, 10000);
//设置每个路由的最多链接数量是20
ConnPerRouteBean connPerRoute = new ConnPerRouteBean(20);
//设置到指定主机的路由的最多数量是50
HttpHost localhost = new HttpHost("127.0.0.1",80);
connPerRoute.setMaxForRoute(new HttpRoute(localhost),50);
ConnManagerParams.setMaxConnectionsPerRoute(params, connPerRoute);
//设置链接使用的版本
HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
//设置链接使用的内容的编码
HttpProtocolParams.setContentCharset(params,
HTTP.DEFAULT_CONTENT_CHARSET);
//是否希望可以继续使用.
HttpProtocolParams.setUseExpectContinue(params, true);
SchemeRegistry schemeRegistry = new SchemeRegistry();
schemeRegistry.register(new Scheme("http",PlainSocketFactory.getSocketFactory(),80));
schemeRegistry.register(new Scheme("https",SSLSocketFactory.getSocketFactory(),443));
ClientConnectionManager cm = new ThreadSafeClientConnManager(params,schemeRegistry);
httpClient = new DefaultHttpClient(cm, params);
7.实用的一个对象,http上下文,可以从这个对象里面取到一次请求相关的信息,例如request,response,代理主机等。
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
public staticvoid getUrl(String url, String encoding)
HttpContext localContext = new BasicHttpContext();
// 得到返回的response.第二个参数,是上下文,很好的一个参数!
httpclient.execute(get, localContext);
// 从上下文中得到HttpConnection对象
HttpConnection con = (HttpConnection) localContext
.getAttribute(ExecutionContext.HTTP_CONNECTION);
System.out.println("socket超时时间:" + con.getSocketTimeout());
// 从上下文中得到HttpHost对象
HttpHost target = (HttpHost) localContext
.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
System.out.println("最终请求的目标:" + target.getHostName() +":"
+ target.getPort());
// 从上下文中得到代理相关信息.
HttpHost proxy = (HttpHost) localContext
.getAttribute(ExecutionContext.HTTP_PROXY_HOST);
if (proxy != null)
System.out.println("代理主机的目标:" + proxy.getHostName() +":"
+ proxy.getPort());
System.out.println("是否发送完毕:"
+ localContext.getAttribute(ExecutionContext.HTTP_REQ_SENT));
// 从上下文中得到HttpRequest对象
HttpRequest request = (HttpRequest) localContext
.getAttribute(ExecutionContext.HTTP_REQUEST);
System.out.println("请求的版本:" + request.getProtocolVersion());
Header[] headers = request.getAllHeaders();
System.out.println("请求的头信息: ");
for (Header h : headers) {
System.out.println(h.getName() + "--" + h.getValue());
System.out.println("请求的链接:" + request.getRequestLine().getUri());
// 从上下文中得到HttpResponse对象
HttpResponse response = (HttpResponse) localContext
.getAttribute(ExecutionContext.HTTP_RESPONSE);
System.out.println("返回结果内容编码是:" + entity.getContentEncoding());
System.out.println("返回结果内容类型是:" + entity.getContentType());
输出结果大致如下:
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
socket超时时间:0
最终请求的目标:money.finance.sina.com.cn:-1
是否发送完毕:true
请求的版本:HTTP/1.1
请求的头信息:
Host--money.finance.sina.com.cn
Connection--Keep-Alive
User-Agent--Apache-HttpClient/4.2.2 (java1.5)
请求的链接:/corp/go.php/vFD_BalanceSheet/stockid/600031/ctrl/part/displaytype/4.phtml
返回结果内容编码是:null
返回结果内容类型是:Content-Type: text/html
8.设置代理
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
//String hostIp代理主机ip,int port 代理端口
tpHost proxy = new HttpHost(hostIp, port);
// 设置代理主机.
tpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY,
proxy);
9.设置保持链接时间
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiIml2ZukHcvN2Xu92Yp9CXzV2Zh1WavwVbvNmLllXZ0lmLwITMllmauVmcvw1LcpDc0RHaiojIsJye.gif)
//在服务端设置一个保持持久连接的特性.
//HTTP服务器配置了会取消在一定时间内没有活动的链接,以节省系统的持久性链接资源.
httpClient.setKeepAliveStrategy(new ConnectionKeepAliveStrategy() {
public long getKeepAliveDuration(HttpResponse response,
HttpContext context) {
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 {
return Long.parseLong(value) *1000;
} catch (Exception e) {
}
HttpHost target = (HttpHost)context.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
if("www.baidu.com".equalsIgnoreCase(target.getHostName())){
return 5*1000;
else
return 30*1000;
}
});
转账注明出处:http://renjie120.iteye.com/blog/1727933