android 请求网络 和 httpclient的使用上传下载

访问网络最主要的也就是 http协议了。

http协议很简单，但是很重要。

直接上代码了，里面都是1个代码块 代码块的，用哪一部分直接拷出去用就好了。

1.访问网络用 get 和 post  自己组拼提交参数 ，httpclient 方式提交

2.上传 和 下载

3.比如访问服务器后 返回来的 xml 和 json 的简单解析方法

String  path = "http://192.168.13.1";
	String  username ="ll";
	String  pwd="123";

	/**   get 组拼    */
	public void  httpGet()
			throws Exception {

		String param1 = URLEncoder.encode(username);
		String param2 = URLEncoder.encode(pwd);
		URL url = new URL(path + "?name=" + param1 + "&password=" + param2);
		HttpURLConnection conn = (HttpURLConnection) url.openConnection();
		conn.setRequestMethod("GET");
		conn.setReadTimeout(5000);
		// 数据并没有发送给服务器
		// 获取服务器返回的流信息
		InputStream in = conn.getInputStream();
		byte[] result = StreamTool.getBytes(in);

		//return new String(result);
	}

	/** post  组拼   */
	public  void  httpPost() throws Exception {

		URL url = new URL(path);
		String param1 = URLEncoder.encode(username);
		String param2 = URLEncoder.encode(pwd);
		//开始连接
		HttpURLConnection conn = (HttpURLConnection) url.openConnection();
		String data = "username=" + param1 + "&password=" + param2;
		//设置方式 post
		conn.setRequestMethod("POST");
		//timeout  5000
		conn.setConnectTimeout(5000);
		// 设置 http协议可以向服务器写数据
		conn.setDoOutput(true);
		// 设置http协议的消息头
		conn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
		conn.setRequestProperty("Content-Length",  String.valueOf(data.length()));
		// 把我们准备好的data数据写给服务器
		OutputStream os = conn.getOutputStream();
		os.write(data.getBytes());
		// httpurlconnection 底层实现 outputstream 是一个缓冲输出流
		// 只要我们获取任何一个服务器返回的信息 , 数据就会被提交给服务器 , 得到服务器返回的流信息
		int code = conn.getResponseCode();
		if (code == 200) {
			InputStream is = conn.getInputStream();
			byte[] result = StreamTool.getBytes(is);
			String ss= new String(result);
		}

	}

	/**   httpclient  get   */
	public void httpClentGet () throws Exception{
		//获取到一个浏览器的实例
		HttpClient client = new DefaultHttpClient();
		//准备请求的地址
		String param1 = URLEncoder.encode(username);
		String param2 = URLEncoder.encode(pwd);
		HttpGet httpGet = new HttpGet(path + "?name=" + param1 + "&password=" + param2);
		//敲回车 发请求
		HttpResponse  ressponse = client.execute(httpGet);
		int code = ressponse.getStatusLine().getStatusCode();
		if( code ==  200){
			InputStream is  =ressponse.getEntity().getContent();
			//byte[] result = StreamTool.getBytes(is);

		}

	}

	//	不需要的时候关闭 httpclient   client.getConnectionManager().shutdown();
	/**    httpclient  post **/
	public  void httpClentPost() throws Exception{
		//1. 获取到一个浏览器的实例
		HttpClient client = new DefaultHttpClient();
		HttpPost httppost = new HttpPost(path);
		// 键值对  BasicNameValuePair
		List<NameValuePair> parameters = new ArrayList<NameValuePair>();
		parameters.add(new BasicNameValuePair("username", username));
		parameters.add(new BasicNameValuePair("pwd", pwd));
		UrlEncodedFormEntity entity = new UrlEncodedFormEntity(parameters, "utf-8");
		//3.设置post请求的数据实体
		httppost.setEntity(entity);
		//4. 发送数据给服务器
		HttpResponse  ressponse = client.execute(httppost);
		int code = ressponse.getStatusLine().getStatusCode();
		if(code == 200){
			InputStream is  =ressponse.getEntity().getContent();
			byte[] result = StreamTool.getBytes(is);

			//return new String(result);
		}

	}

	/*** 下载一个东西    ***/
	public void getFileData(Context context){

		try {
		     HttpClient client = new DefaultHttpClient();
		     HttpGet httpGet = new HttpGet(path);
			 //执行
			 HttpResponse  ressponse = client.execute(httpGet);
			 int code = ressponse.getStatusLine().getStatusCode();

			      if(code == HttpStatus.SC_OK){
						InputStream in =ressponse.getEntity().getContent();
						//图片
//						Bitmap bitmap = BitmapFactory.decodeStream(in);
//						in.close();

						//文件什么的比如读取了是要写在本地的
						//小文件直接读取   大文件读取一点写一点
						//byte[] result = StreamTool.getBytes(in);
						//

						 //这里可以得到文件的类型 如image/jpg /zip /tiff 等等 但是发现并不是十分有效，有时明明后缀是.rar但是取到的是null，这点特别说明
                        System.out.println(ressponse.getEntity().getContentType());
                        //可以判断是否是文件数据流
                        System.out.println(ressponse.getEntity().isStreaming());
                        //设置本地保存的文件
                        //File storeFile = new File("c:/0431la.zip");
                        String path="sdcard/aa.txt";
                        FileOutputStream output = context.openFileOutput(path, context.MODE_PRIVATE);
                        //得到网络资源并写入文件
                        InputStream input = ressponse.getEntity().getContent();
                        byte b[] = new byte[1024];
                        int j = 0;
                        while( (j = input.read(b))!=-1){
                             output.write(b,0,j);
                        }
                        output.flush();
                        output.close();
				     }
		} catch (Exception e) {
			// TODO: handle exception
		}
	}

	/**
	 * 提交数据给服务器 带一个文件
	 * @param filepath 文件在手机上的路径
	 */
	public void PostData(String filepath) throws Exception{

		// 实例化上传数据的 数组  part [] username  pwd
		Part[] parts = {
				  new StringPart("username", username),
				  new StringPart("pwd", pwd),
				  new FilePart("file", new File(filepath))
				  };

		PostMethod file_Post = new PostMethod(path);
	    //                              多种类型的数据实体
		file_Post.setRequestEntity(new MultipartRequestEntity(parts, file_Post.getParams()));
		//创建 client
		org.apache.commons.httpclient.HttpClient client = new org.apache.commons.httpclient.HttpClient();
        //timeout
		client.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
		//执行
		int status = client.executeMethod(file_Post);

		if(status==200){

		}

	}

	//传送文件
	public void setFile() throws Exception{

		 HttpClient httpclient = new DefaultHttpClient();
	     HttpPost httppost = new HttpPost("http://192.168.1.1");
	     File file = new File(path);
	     InputStreamEntity reqEntity = new InputStreamEntity(
	             new FileInputStream(file), -1);
	     reqEntity.setContentType("binary/octet-stream");
	     reqEntity.setChunked(true);   

	     // FileEntity entity = new FileEntity(file, "binary/octet-stream");
	     httppost.setEntity(reqEntity);
	     System.out.println("executing request " + httppost.getRequestLine());
	     HttpResponse response = httpclient.execute(httppost); 

         if(response.getStatusLine().getStatusCode() == 200){

         }

	}

	/** 1.
	 *  一般访问了就会返回来1个  webservice
	 *  pull解析访问webservice 返回来的xml
	 *   **/

	public void  pullJX(byte[]  bb)  throws Exception{
		// byte[] bb = EntityUtils.toByteArray(response.getEntity());
		 XmlPullParser pullParser = Xml.newPullParser();
		 pullParser.setInput(new ByteArrayInputStream(bb), "UTF-8");
		 int event = pullParser.getEventType();
	     List<Object> info;
		 while(event != XmlPullParser.END_DOCUMENT){
			      switch (event) {
					   case XmlPullParser.START_DOCUMENT:
						info = new ArrayList<Object>();
						break;

					   case XmlPullParser.START_TAG:
						if("aa".equals(pullParser.getName())){
							String id = pullParser.nextText().toString();

						}
						break;

					   case XmlPullParser.END_TAG:
						  if("aa".equals(pullParser.getName())){
						 }
				      break;
			      }
			event = pullParser.next();
		  }
	}

	/**2.
	 *  解析 json  数据 [{id:"001",name:"lilei",age:"20"},{id:"002",name:"zhangjia",age:"30"}]
	 */
	private static List parseJSON(InputStream  in) throws Exception{
		byte[] data = StreamTool.getBytes(in);
		String s =new String(data);
		// 转换成  json 数组对象   [{"001","ll","20"},{"002","zj","30"},]
		JSONArray json = new JSONArray(s);
			for (int i = 0; i < json.length() ; i++) {
				  JSONObject j = json.getJSONObject(i);
			      String aa1 = j.getString("id");
			      String aa2 = j.getString("name");
			      String aa3 = j.getString("age");
			}
		  return  null;
	   }
	

HttpClient其实是一个interface类型，HttpClient封装了对象需要执行的Http请求、身份验证、连接管理和其它特性

HttpClient有三个已知的实现类分别是：

AbstractHttpClient, AndroidHttpClient, DefaultHttpClient

AndroidHttpClient是对HttpClient的包装，内部带访问连接器，并设置为可以多线程使用，

public class MyApplication extends Application{

	 private AndroidHttpClient httpClient;

      //  application oncreate的时候创建
      public void onCreate(){
          super.onCreate();
          httpClient =  AndroidHttpClient.newInstance("Android");
      }

      //供外部调用
      public AndroidHttpClient getHttpClient() {
        if (httpClient == null){
    	   httpClient = AndroidHttpClient.newInstance("Android");
        }
        return httpClient;
      }

	  @Override
	  public void onLowMemory() {
	    super.onLowMemory();
	    shutdownHttpClient();
	  }

	  @Override
	  public void onTerminate() {
	    super.onTerminate();
	    shutdownHttpClient();
	  }

      //关闭
	  private void shutdownHttpClient() {
	    if (httpClient != null) {
	      if (httpClient.getConnectionManager() != null) {
	        httpClient.getConnectionManager().shutdown();
	      }
	      httpClient.close();
	      httpClient = null;
	    }
	  }

}

外部调用的话

AndroidHttpClient httpClient = ((MyApplication)getApplication()).getHttpClient();