提交数据到服务器、文件上传、多线程下载

来源：互联网发布：中文域名不允许个人编辑：程序博客网时间：2024/06/07 02:48

1 post方式提交数据乱码的解决

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/jwb/servlet/LoginServlet?username="+URLEncoder.encode(username)+"&pwd="+URLEncoder.encode(password));connection.setDoOutput(true);connection.getOutputStream().write(parmes.getBytes());

2 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/jwb/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/jwb/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Entity                        UrlEncodedFormEntity 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();                }

3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/jwb/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://192.168.13.83:8080/jwb/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) {                }            });

4 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url        asyncHttpClient.post("http://192.168.13.83:8080/itheima74/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();        }    }

5 多线程加速下载的原理

    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    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。

6 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>() {            @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            }        });    }

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