上传/下载/get和post请求的区别

最新推荐文章于 2023-09-25 13:17:26 发布

原创最新推荐文章于 2023-09-25 13:17:26 发布 · 628 阅读

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CC 4.0 BY-SA版权

文章标签：

#http #网络协议 #网络

该代码示例展示了在Android中使用HttpURLConnection进行文件上传和下载的方法。上传通过POST请求实现，设置multipart/form-data内容类型，添加文件边界并读取文件流。下载则通过GET请求获取服务器资源，写入到本地文件。

上传

public String upLoda(String urlpath,String filepath)
    {
        String  BOUNDARY = UUID.randomUUID().toString();
        String PREFIX = "--" , LINE_END = "\r\n";
        String CONTENT_TYPE = "multipart/form-data";
        try {
            URL url = new URL(urlpath);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            httpURLConnection.setReadTimeout(5000);
            httpURLConnection.setConnectTimeout(5000);
            httpURLConnection.setRequestProperty("Content-Type",CONTENT_TYPE +";boundary="+ BOUNDARY);
            httpURLConnection.connect();
            File file = new File(filepath);
            if (file!=null)
            {
                OutputStream outputStream = httpURLConnection.getOutputStream();
                StringBuffer stringBuffer = new StringBuffer();
                //真正数据流发送前进行边界设置
                stringBuffer.append(PREFIX);
                stringBuffer.append(BOUNDARY);
                stringBuffer.append(LINE_END);
                stringBuffer.append("Content-Disposition: form-data; name=\"file\"; filename=\""+file.getName()+"\""+LINE_END);
                stringBuffer.append(LINE_END);
                outputStream.write(stringBuffer.toString().getBytes());
                //真数据流部分
                InputStream inputStream = new FileInputStream(file);
                byte[] bytes = new byte[1024];
                int len = 0;
                while ((len=inputStream.read(bytes))!=-1)
                {
                    outputStream.write(bytes,0,len);
                }
                inputStream.close();
                //真正数据流完毕需要设定结尾标记
                outputStream.write(LINE_END.getBytes());
                byte[] enddata = (PREFIX+BOUNDARY+PREFIX+LINE_END).getBytes();
                outputStream.write(enddata);
                outputStream.flush();
                if (httpURLConnection.getResponseCode()==200)
                {

                }
            }

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

@Override
    protected String doInBackground(String... strings) {
//        String string = HtppUtils.getInstance().getString(strings[0]);
//        String  strings1 = strings[0];
//        String string2 = strings[1];
//        String s = HtppUtils.getInstance().PostString(strings1, string2);
//        Log.i("sss", "doInBackground: "+s+string2);
//        String s = HtppUtils.getInstance().DownLoad(strings[0]);
        String urlpath = strings[0];
        String filepath = strings[1];
        HtppUtils.getInstance().upLoda(urlpath,filepath);
        return null;
    }

public void upload(View view) {
        new MyAsyncTask().execute("http://10.161.11.62/nihao/","/sdcard/hh.jpg");
    }

记得开启权限

下载

public void download(View view) {
        new MyAsyncTask().execute("https://img0.baidu.com/it/u=1684532727,1424929765&fm=253&fmt=auto&app=120&f=JPEG?w=1200&h=675");
    }

public String DownLoad(String path)
    {
        try {
            URL url = new URL(path);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("GET");
            httpURLConnection.setReadTimeout(2000);
            httpURLConnection.setConnectTimeout(2000);
            httpURLConnection.connect();
            if (httpURLConnection.getResponseCode()==200)
            {
                int len = 0;
                byte[] buffer = new byte[1024];
                InputStream inputStream = httpURLConnection.getInputStream();
                if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
                {
                    File downloadCacheDirectory = Environment.getExternalStorageDirectory();
                    File file = new File(downloadCacheDirectory,"hh.jpg");
                    FileOutputStream fileOutputStream = new FileOutputStream(file);
                    while ((len = inputStream.read(buffer))!=-1)
                    {
                        fileOutputStream.write(buffer,0,len);
                    }
                }
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

@Override
    protected String doInBackground(String... strings) {
//        String string = HtppUtils.getInstance().getString(strings[0]);
//        String  strings1 = strings[0];
//        String string2 = strings[1];
//        String s = HtppUtils.getInstance().PostString(strings1, string2);
//        Log.i("sss", "doInBackground: "+s+string2);
          String s = HtppUtils.getInstance().DownLoad(strings[0]);
        return null;
    }

GET获取数据

public String getString(String path)
    {
        try {
            URL url = new URL(path);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("GET");
            httpURLConnection.setReadTimeout(2000);
            httpURLConnection.setConnectTimeout(2000);
            httpURLConnection.connect();
            if (httpURLConnection.getResponseCode()==200)
            {
//                InputStream inputStream = httpURLConnection.getInputStream();
//                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
//                String str="";
//                StringBuilder stringBuilder = new StringBuilder();
//                while ((str=bufferedReader.readLine())!=null)
//                {
//                    stringBuilder.append(str);
//                }
                InputStream inputStream = httpURLConnection.getInputStream();
                int len = 0;
                byte[] buffer = new byte[1024];
                StringBuilder stringBuilder = new StringBuilder();
                while ((len=inputStream.read(buffer))!=-1)
                {
                    stringBuilder.append(new String(buffer,0,len));
                }
                Log.i("sss", "doInBackground: "+stringBuilder.toString());
                return stringBuilder.toString();
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

POST获取数据

public String PostString(String path,String params)
    {
        try {
            URL url = new URL(path);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setReadTimeout(2000);
            httpURLConnection.setConnectTimeout(2000);
            httpURLConnection.setDoInput(true);
            httpURLConnection.setDoOutput(true);
            httpURLConnection.connect();
            OutputStream outputStream = httpURLConnection.getOutputStream();
            outputStream.write(params.getBytes());
            outputStream.flush();
            if (httpURLConnection.getResponseCode()==200)
            {
                byte[] bytes = new byte[1024];
                int len = 0;
                InputStream inputStream = httpURLConnection.getInputStream();
                StringBuilder stringBuilder = new StringBuilder();
                while ((len = inputStream.read(bytes))!=-1)
                {
                    stringBuilder.append(new String(bytes,0,len));
                }
                return stringBuilder.toString();
            }

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

get和post请求的区别

1.GET在浏览器回退时是无害的，而POST会再次提交请求。

2.GET产生的URL地址可以被Bookmark(书签),而POST不可以。

3.GET请求会被浏览器主动cache,而POST不会，除非手动设置。

4.GET请求只能进行url编码，而POST支持多种编码方式。

5.GET请求参数会被完整保留在浏览器历史记录里，而POST中的参数不会别保留。

6.GET请求在URL中传送的参数是有长度限制的，而POST没有。

7.对参数的数据类型，GET只能接受ASCLL字符，而POST没有限制。

8.GET比POST更不安全，因为参数直接暴露在URL上，所有不能用来传递敏感信息。

9.GET参数通过URL传递，POST放在Request body中。