Android 基础知识05

##Android基础网络第二天


# 1 post方式提交数据乱码的解决


一般在公司开发客户端和服务端的编码要保持一致。
android端的默认编码是utf-8;


做url请求时需要对参数进行URLEncode编码.


URL url = new URL("http://192.168.13.83:8080/itheima74/servlet/LoginServlet?username="+URLEncoder.encode(username)+"&pwd="+URLEncoder.encode(password));

connection.setDoOutput(true);connection.getOutputStream().write(parmes.getBytes());

# 2 get方式提交数据乱码解决

URLEncode


# 3 httpclient方式提交数据到服务器


HttpClient:


get方式:

//使用HttpClient请求服务器将用户密码发送服务器验证try{String path = "http://192.168.13.83:8080/itheima74/servlet/LoginServlet?username="+URLEncoder.encode(username,"utf-8")+"&pwd="+URLEncoder.encode(password,"utf-8");//1.创建一个httpClient对象HttpClient httpclient = new DefaultHttpClient();//2.设置请求的方式HttpGet httpget = new HttpGet(path);//3.执行一个http请求HttpResponse response = httpclient.execute(httpget);//4.获取请求的状态码，StatusLine statusLine = response.getStatusLine();int code = statusLine.getStatusCode();//5.判断状态码后获取内容if(code == 200){HttpEntity entity = response.getEntity();//获取实体内容，中封装的有http请求返回的流信息InputStream inputStream = entity.getContent();//将流信息转换成字符串String result = StreamUtils.streamToString(inputStream);Message msg = Message.obtain();msg.what = 1;msg.obj = result;handler.sendMessage(msg);}}catch (Exception e) {e.printStackTrace();}

post方式：

//使用UrlConncetion请求服务器将用户密码发送服务器验证try{String path = "http://192.168.13.83:8080/itheima74/servlet/LoginServlet";//1.创建一个httpclient对象HttpClient httpclient = new DefaultHttpClient();//2.创建一个请求方式HttpPost httppost = new HttpPost(path);//创建集合封装数据ArrayList<BasicNameValuePair> arrayList = new ArrayList<BasicNameValuePair>();BasicNameValuePair nameValuePair = new BasicNameValuePair("username",username);arrayList.add(nameValuePair);BasicNameValuePair nameValuePair1 = new BasicNameValuePair("pwd",password);arrayList.add(nameValuePair1);//创建一个EntityUrlEncodedFormEntity entity = new UrlEncodedFormEntity(arrayList, "utf-8");//设置请求时的内容httppost.setEntity(entity);//3.执行一个请求,返回一个response对象HttpResponse response = httpclient.execute(httppost);//4.获取状态码int code = response.getStatusLine().getStatusCode();//5.判断并获取内容if(code == 200){HttpEntity entity1 = response.getEntity();//获取实体内容，中封装的有http请求返回的流信息InputStream inputStream = entity1.getContent();//将流信息转换成字符串String result = StreamUtils.streamToString(inputStream);Message msg = Message.obtain();msg.what = 2;msg.obj = result;handler.sendMessage(msg);}}catch (Exception e) {e.printStackTrace();}

   
# 4开源项目get post 方式提交 (asyncHttpClient)  




get方式：

public static void requestNetForGetLogin(final Context context,final Handler handler ,final String username, final String password) {//使用HttpClient请求服务器将用户密码发送服务器验证try{String path = "http://192.168.13.83:8080/itheima74/servlet/LoginServlet?username="+URLEncoder.encode(username,"utf-8")+"&pwd="+URLEncoder.encode(password,"utf-8");//创建一个AsyncHttpClient对象AsyncHttpClient asyncHttpClient = new AsyncHttpClient();asyncHttpClient.get(path, new AsyncHttpResponseHandler() {@Overridepublic void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {//statusCode:状态码    headers：头信息  responseBody：返回的内容，返回的实体//判断状态码if(statusCode == 200){//获取结果try {String result = new String(responseBody,"utf-8");Toast.makeText(context, result, 0).show();} catch (UnsupportedEncodingException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}@Overridepublic void onFailure(int statusCode, Header[] headers,byte[] responseBody, Throwable error) {System.out.println("...............onFailure");}});}catch (Exception e) {e.printStackTrace();}}

post方式：

String path = "http://192.168.13.83:8080/itheima74/servlet/LoginServlet";AsyncHttpClient asyncHttpClient = new AsyncHttpClient();RequestParams params = new RequestParams();params.put("username", username);params.put("pwd", password);//url:   parmas：请求时携带的参数信息   responseHandler：是一个匿名内部类接受成功过失败asyncHttpClient.post(path, params, new AsyncHttpResponseHandler() {@Overridepublic void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {//statusCode:状态码    headers：头信息  responseBody：返回的内容，返回的实体//判断状态码if(statusCode == 200){//获取结果try {String result = new String(responseBody,"utf-8");Toast.makeText(context, result, 0).show();} catch (UnsupportedEncodingException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}@Overridepublic void onFailure(int statusCode, Header[] headers,byte[] responseBody, Throwable error) {}});

# 5 文件上传的操作 

使用第三方utils做文件上传。

public void fileupload(View v){try{EditText et_filepath = (EditText) findViewById(R.id.et_filepath);//获取输入的文件地址String filepath = et_filepath.getText().toString().trim();//使用开源Utils做上传操作AsyncHttpClient asyncHttpClient = new AsyncHttpClient();RequestParams params = new RequestParams();params.put("filename", new File(filepath));//url : 请求服务器的urlasyncHttpClient.post("http://192.168.13.83:8080/itheima74/servlet/UploaderServlet", params, new AsyncHttpResponseHandler() {@Overridepublic void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {if(statusCode == 200){Toast.makeText(MainActivity.this, "上传成功", 0).show();}}@Overridepublic void onFailure(int statusCode, Header[] headers,byte[] responseBody, Throwable error) {}});}catch (Exception e) {e.printStackTrace();}}

# 6 多线程加速下载的原理


1.线程越多下载越快？？ 不是。 与 本地网络带宽， 服务器资源的带宽 有关
2.迅雷：3-5个。


多线程下载的步骤：


1.要知道服务端资源的大小。

通过URLConnection请求服务器url获取。
UrlConnection.getContentLength();//资源的大小

2.在本地创建一个与服务端资源同样大小的一个文件（占位）
//file :  文件； mode:文件的模式，rwd：直接写到底层设备，硬盘
RandomAccessFile randomfile =new RandomAccessFile(File file,String mode)

randomfile.setLength(long size);//创建一个文件和服务器资源一样大小

3.要分配每个线程下载文件的开始位置和结束位置。

4.开启线程去执行下载
通过UrlConnection下载部分资源。
注意：
1.需要Range头，key：Range   value：bytes:0-499 
urlconnection.setRequestPropety("Range","bytes:0-499")
2.需要设置每个线程在本地文件的保存的开始位置
RandomAccessFile randomfile =new RandomAccessFile(File file,String mode)
randomfile.seek(int startPostion);//本次线程下载保存的开始位置。

5.要知道每个线程下载完毕。


# 7 javase 多线程下载


# 8 多线程断点续传实现


# 9 Android版本多线程下载


安智： sdcard没有判断。uc

# 10 开源项目实现多线程下载 (xutils)

public void download(View v){EditText et_url = (EditText) findViewById(R.id.et_url);String url = et_url.getText().toString().trim();//1.创建httpUtils对象HttpUtils httpUtils = new HttpUtils();//2.调用download方法  url:下载的地址  target：下载的目录   callback：回调 httpUtils.download(url, "/sdcard/feiqiu/feiq.exe", new RequestCallBack<File>() {@Overridepublic void onLoading(long total, long current, boolean isUploading) {System.out.println("total:"+total+";current:"+current);super.onLoading(total, current, isUploading);}@Overridepublic void onSuccess(ResponseInfo<File> responseInfo) {System.out.println(responseInfo.result);}@Overridepublic void onFailure(HttpException error, String msg) {// TODO Auto-generated method stub}});}

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