本文为android开发基础课程网络编程系列文章，关于接口，权限的声明与配置，请看前面的文章。

课程地址：

Android网络编程

接口地址

方法：post

/file/upload

参数file

多文件上传

/files/upload

方法post 参数 files

抓包

我们前面已经了解了http的请求格式，那么如果我们不知道如何上传文件，那怎么整呢？

用postMan上传一个文件抓个包不就知道了嘛！

尾部：

我们按照这个套路，去拼接内容，不就可以啦！对吧！

代码实现

private void uploadFile(File file,
                                    String fileKey,
                                    String fileName,
                                    String fileType,
                                    String BOUNDARY,
                                    OutputStream outputStream,
                                    boolean isLast) throws IOException {
                //准备数据
                StringBuilder headerSbInfo = new StringBuilder();
                headerSbInfo.append("--");
                headerSbInfo.append(BOUNDARY);
                headerSbInfo.append("\r\n");
                headerSbInfo.append("Content-Disposition: form-data; name=\"" + fileKey + "\"; filename=\"" + fileName + "\"");
                headerSbInfo.append("\r\n");
                headerSbInfo.append("Content-Type: " + fileType);
                headerSbInfo.append("\r\n");
                headerSbInfo.append("\r\n");
                byte[] headerInfoBytes = headerSbInfo.toString().getBytes("UTF-8");
                outputStream.write(headerInfoBytes);
                //文件内容
                FileInputStream fos = new FileInputStream(file);
                BufferedInputStream bfi = new BufferedInputStream(fos);
                byte[] buffer = new byte[1024];
                int len;
                while((len = bfi.read(buffer,0,buffer.length)) != -1) {
                    outputStream.write(buffer,0,len);
                }
                //写尾部信息
                StringBuilder footerSbInfo = new StringBuilder();
                footerSbInfo.append("\r\n");
                footerSbInfo.append("--");
                footerSbInfo.append(BOUNDARY);
                if(isLast) {
                    footerSbInfo.append("--");
                    footerSbInfo.append("\r\n");
                }
                footerSbInfo.append("\r\n");
                outputStream.write(footerSbInfo.toString().getBytes("UTF-8"));
            }

如果这个不方便理解，就看视频吧。一次就能看懂了。

这里面跟格式有关系，单文件和多文件的都有了。

如果是多文件，其实我们是向body里多添加几个文件而已，格式一样的。

所以就有了这样的调用。

多文件上传调用

    OutputStream outputStream = null;
                try {
                    File fileOne = new File("/storage/emulated/0/Download/1.jpg");
                    File fileTwo = new File("/storage/emulated/0/Download/rBsADV2rEz-AIzSoAABi-6nfiqs456.png");
                    File fileThree = new File("/storage/emulated/0/Download/2.jpg");
                    File fileFour = new File("/storage/emulated/0/Download/rBPLFV2A8POASi1aAAE-PgvGzOo723.jpg");
                    String fileKey = "files";
                    String fileType = "image/jpeg";
                    String BOUNDARY = "--------------------------954555323792164398227139";
                    //String BOUNDARY = "----------------------------954555323792164398227139--";
                    //String BOUNDARY = "----------------------------954555323792164398227139";
                    URL url = new URL(BASE_URL + "/files/upload");
                    HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                    httpURLConnection.setRequestMethod("POST");
                    httpURLConnection.setConnectTimeout(10000);
                    httpURLConnection.setRequestProperty("User-Agent","Android/" + Build.VERSION.SDK_INT);
                    httpURLConnection.setRequestProperty("Accept","*/*");
                    httpURLConnection.setRequestProperty("Cache-Control","no-cache");
                    httpURLConnection.setRequestProperty("Content-Type","multipart/form-data; boundary=" + BOUNDARY);
                    httpURLConnection.setRequestProperty("Connection","keep-alive");
                    httpURLConnection.setDoOutput(true);
                    httpURLConnection.setDoInput(true);
                    //连接
                    httpURLConnection.connect();
                    outputStream = httpURLConnection.getOutputStream();
                    uploadFile(fileOne,fileKey,fileOne.getName(),fileType,BOUNDARY,outputStream,false);
                    uploadFile(fileTwo,fileKey,fileTwo.getName(),fileType,BOUNDARY,outputStream,false);
                    uploadFile(fileFour,fileKey,fileFour.getName(),fileType,BOUNDARY,outputStream,false);
                    uploadFile(fileThree,fileKey,fileThree.getName(),fileType,BOUNDARY,outputStream,true);
                    outputStream.flush();
                    //获取返回的结果
                    int responseCode = httpURLConnection.getResponseCode();
                    Log.d(TAG,"responseCode -- > " + responseCode);
                    if(responseCode == HttpURLConnection.HTTP_OK) {
                        InputStream inputStream = httpURLConnection.getInputStream();
                        BufferedReader bf = new BufferedReader(new InputStreamReader(inputStream));
                        String result = bf.readLine();
                        Log.d(TAG,"result -- > " + result);
                    }
                } catch(Exception e) {
                    e.printStackTrace();
                } finally {
                    if(outputStream != null) {
                        try {
                            outputStream.close();
                        } catch(IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }

okay啦，详细内容请看视频吧，感谢同学们的支持与关注