Android网络编程基础(二)

Android学习笔记，整理给自己复习的时候看的，谢谢！

1 post方式提交数据乱码的解决

Android端的默认编码是utf-8;一般在公司开发客户端和服务端的编码要保持一致。做url请求时需要对参数进行URLEncode编码.

URL url = new URL("http:// 169.254.248.190:8080/jokerjohn/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（23以后用得少了）

• 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://169.254.248.190:8080/jokerjohn/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://169.254.248.190:8080/jokerjohn/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 asyncHttpClient 方式提交

• 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://169.254.248.190:8080/jokerjohn/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() {                    @Override                    public 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 block                                e.printStackTrace();                            }                        }                    }                    @Override                    public 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://169.254.248.190:8080/jokerjohn/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() {                @Override                public 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 block                            e.printStackTrace();                        }                    }                }                @Override                public void onFailure(int statusCode, Header[] headers,                        byte[] responseBody, Throwable error) {                }            });

5 文件上传操作

- 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url        asyncHttpClient.post("http://169.254.248.190:8080/jokerjohn/servlet/UploaderServlet", params, new AsyncHttpResponseHandler() {            @Override            public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {                if(statusCode == 200){                    Toast.makeText(MainActivity.this, "上传成功", 0).show();                }            }            @Override            public 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 开源项目xutils实现多线程下载

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>() {            @Override            public void onLoading(long total, long current, boolean isUploading) {                System.out.println("total:"+total+";current:"+current);                super.onLoading(total, current, isUploading);            }            @Override            public void onSuccess(ResponseInfo<File> responseInfo) {                System.out.println(responseInfo.result);            }            @Override            public void onFailure(HttpException error, String msg) {                // TODO Auto-generated method stub            }        });    }