利用Android自带的http包进展网络请求

利用Android自带的http包进行网络请求
目的是为了不依赖第三方的jar包进行网络请求（如：commons-httpclient.jar）

修改了一下，可以自定义请求的Header，增加了对POST表单数据的支持。

1. 建立一个连接配置类

class UserAgentConfig {	public String host;	public String scheme = "http";	public int port = 80;	public int timeoutConnection = 3000;	public int timeoutSocket = 20000;	public String username = "";	public String password = "";}

2. 封装请求类

public class HttpRequest {	private String mUrl;	private UserAgentConfig mConfig = null;	private HashMap<String, String> mHeaders = null;	private HttpEntity mBody = null;	private int mStatus = -1;	public HttpRequest(String url) {		mUrl = url;	}	public void addHeader(String key, String value) {		if (mHeaders == null)			mHeaders = new HashMap<String, String>();		mHeaders.put(key, value);	}	public void clearHeader() {		mHeaders.clear();		mHeaders = null;	}	public void setConfig(UserAgentConfig config) {		mConfig = config;	}	public void setPostBody(List<BasicNameValuePair> body) {		try {			mBody = new UrlEncodedFormEntity(body, "utf-8");		} catch (UnsupportedEncodingException e) {			e.printStackTrace();		}	}	public void setPostBody(String body) {		try {			mBody = new StringEntity(body);		} catch (UnsupportedEncodingException e) {			e.printStackTrace();		}	}	public void execute() throws ClientProtocolException, IOException {		httprequest();	}	public int getStatusCode() {		return mStatus;	}	/**	 * get "Stream" as response	 * 	 * @return response in stream	 * @throws IOException	 * @throws ClientProtocolException	 */	public InputStream getStream() throws ClientProtocolException, IOException {		HttpEntity entity = httprequest();		InputStream ret = null;		if (entity != null) {			try {				byte[] b = EntityUtils.toByteArray(entity);				ret = new ByteArrayInputStream(b);			} finally {				release(entity);			}		}		return ret;	}	/**	 * get "String" as response	 * 	 * @return response in string	 * @throws IOException	 * @throws ClientProtocolException	 */	public String getString() throws ClientProtocolException, IOException {		HttpEntity entity = httprequest();		String ret = null;		if (entity != null) {			try {				ret = EntityUtils.toString(entity);			} finally {				release(entity);			}		}		return ret;	}	/**	 * release connection resource	 * 	 * @param entity	 */	private static void release(HttpEntity entity) {		try {			entity.consumeContent();		} catch (IOException e) {			e.printStackTrace();		}	}	/**	 * get "HttpEntity" as response	 * 	 * @return	 * @throws IOException	 * @throws ClientProtocolException	 */	private HttpEntity httprequest() throws ClientProtocolException,			IOException {		System.out.println(mUrl);		DefaultHttpClient client = null;		HttpEntity entity = null;		BasicHttpParams httpParameters = new BasicHttpParams();		if (mConfig != null) {			// set connection timeout			HttpConnectionParams.setConnectionTimeout(httpParameters,					mConfig.timeoutConnection);		}		client = new DefaultHttpClient(httpParameters);		DefaultHttpRequestRetryHandler retryHandler = new DefaultHttpRequestRetryHandler(				3, true);		client.setHttpRequestRetryHandler(retryHandler);		// set username & password if available		if (mConfig != null				&& !(isEmpty(mConfig.username) && isEmpty(mConfig.password))) {			AuthScope as = new AuthScope(mConfig.host, mConfig.port);			UsernamePasswordCredentials upc = new UsernamePasswordCredentials(					mConfig.username, mConfig.password);			client.getCredentialsProvider().setCredentials(as, upc);		}		// check get or post method by params		HttpRequestBase method = null;		if (mBody == null) {			method = new HttpGet(mUrl);		} else {			method = new HttpPost(mUrl);			((HttpPost) method).setEntity(mBody);		}		// set request header		if (mHeaders != null) {			Iterator<?> iter = mHeaders.entrySet().iterator();			while (iter.hasNext()) {				Map.Entry<?, ?> entry = (Entry<?, ?>) iter.next();				String key = (String) entry.getKey();				String val = (String) entry.getValue();				method.setHeader(key, val);			}		}		// get response		HttpResponse response = null;		if (mConfig == null || isEmpty(mConfig.host) || isEmpty(mConfig.scheme)) {			// only URL is available			response = client.execute(method);		} else {			BasicHttpContext localContext = new BasicHttpContext();			BasicScheme basicAuth = new BasicScheme();			localContext.setAttribute("preemptive-auth", basicAuth);			HttpHost targetHost = new HttpHost(mConfig.host, mConfig.port,					mConfig.scheme);			response = client.execute(targetHost, method, localContext);		}		mStatus = response.getStatusLine().getStatusCode();		entity = response.getEntity();		return entity;	}	/**	 * Check the string is valuable or not	 * 	 * @param s	 * @return true if s is null or s.length() == 0 false otherwise	 */	private boolean isEmpty(String s) {		return s == null || s.length() == 0;	}}

3. 调用
GET请求

HttpRequest request = new HttpRequest("...");request.execute();

UserAgentConfig config = new UserAgentConfig();config.host = "...";config.username = "...";config.password = "...";HttpRequest request = new HttpRequest("...");request.setConfig(config);System.out.println(request.getString());

POST请求

HttpRequest request = new HttpRequest("...");request.addHeader("...", "...");request.setPostBody("....");request.execute();System.out.println(request.getStatusCode());