[寫著玩]理解multipart/form-data，構造http表單實現android圖片上傳
阿新 • • 發佈：2018-12-23
關於multipart/form-data，可參考https://blog.csdn.net/zshake/article/details/77985757
客戶端
引數解釋，上傳主方法
private void submit() { Map<String, Object> params = new HashMap<String, Object>(); //普通表單，key-value params.put("key", "value"); //圖片表單，支援多檔案上傳，修改引數即可 FormFile[] files = new FormFile[2]; files[0] = new FormFile(String filname, byte[] data, String formname, String contentType); files[1] = new FormFile(String filname, byte[] data, String formname, String contentType); //上傳方法，回撥方法可更新介面 httpService.postHttpImageRequest(url, params, files, new HttpCallBackListener() { public void onFinish(String response) { } public void onError(Exception e) { } }); }
圖片資料bean
public class FormFile { /* 上傳檔案的資料 */ private byte[] data; /* 檔名稱 */ private String filname; /* 表單欄位名稱*/ private String formname; /* 內容型別 */ private String contentType = "application/octet-stream"; //需要查閱相關的資料 public FormFile(String filname, byte[] data, String formname, String contentType) { this.data = data; this.filname = filname; this.formname = formname; if(contentType!=null) this.contentType = contentType; } public byte[] getData() { return data; } public void setData(byte[] data) { this.data = data; } public String getFilname() { return filname; } public void setFilname(String filname) { this.filname = filname; } public String getFormname() { return formname; } public void setFormname(String formname) { this.formname = formname; } public String getContentType() { return contentType; } public void setContentType(String contentType) { this.contentType = contentType; } }
HttpService
public class HttpService { public HttpService() { } public void postHttpImageRequest(final String netWorkAddress,final Map<String, Object> params,final FormFile[] files, final HttpCallBackListener listener) { new Thread(new Runnable() { @Override public void run() { HttpURLConnection connection = null; try { String BOUNDARY = "---------7d4a6d158c9"; //資料分隔線 String MULTIPART_FORM_DATA = "multipart/form-data"; URL url = new URL(UrlInterface.UTILS + netWorkAddress); connection = (HttpURLConnection) url.openConnection(); connection.setDoInput(true);//允許輸入 connection.setDoOutput(true);//允許輸出 connection.setUseCaches(false);//不使用Cache connection.setRequestMethod("POST"); connection.setRequestProperty("Connection", "Keep-Alive"); connection.setRequestProperty("Charset", "UTF-8"); connection.setRequestProperty("Content-Type", MULTIPART_FORM_DATA + "; boundary=" + BOUNDARY); StringBuilder sb = new StringBuilder(); //上傳的表單引數部分 for (Entry<String, Object> entry : params.entrySet()) {//構建表單欄位內容 sb.append("--"); sb.append(BOUNDARY); sb.append("\r\n"); sb.append("Content-Disposition: form-data; name=\""+ entry.getKey() + "\"\r\n\r\n"); sb.append(entry.getValue()); sb.append("\r\n"); } DataOutputStream outStream = new DataOutputStream(connection.getOutputStream()); outStream.write(sb.toString().getBytes());//傳送表單欄位資料 //上傳的檔案部分 for(FormFile file : files){ StringBuilder split = new StringBuilder(); split.append("--"); split.append(BOUNDARY); split.append("\r\n"); split.append("Content-Disposition: form-data; name=\""+ file.getFormname()+"\"; filename=\""+ file.getFilname() + "\"\r\n"); split.append("Content-Type: "+ file.getContentType()+"\r\n\r\n"); outStream.write(split.toString().getBytes()); outStream.write(file.getData(), 0, file.getData().length); outStream.write("\r\n".getBytes()); } byte[] end_data = ("--" + BOUNDARY + "--\r\n").getBytes();//資料結束標誌 outStream.write(end_data); outStream.flush(); int cah = connection.getResponseCode(); if (cah != 200) throw new RuntimeException("請求url失敗"); InputStream in = connection.getInputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(in)); StringBuilder response = new StringBuilder(); String line; while ((line = reader.readLine()) != null) { response.append(line); } if (listener != null) { listener.onFinish(response.toString()); } outStream.close(); } catch (Exception e) { if (listener != null) { listener.onError(e); } } finally { if (connection != null) { connection.disconnect(); } } } }).start(); } public interface HttpCallBackListener { void onFinish(String response); void onError(Exception e); } }
服務端
public class UploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
// 上傳配置
private static final int MEMORY_THRESHOLD = 1024 * 1024 * 3; // 3MB
private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB
private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50; // 50MB
/**
* @see HttpServlet#HttpServlet()
*/
public UploadServlet() {
super();
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/json;charset=utf-8");
// 配置上傳引數
DiskFileItemFactory factory = new DiskFileItemFactory();
// 設定記憶體臨界值 - 超過後將產生臨時檔案並存儲於臨時目錄中
factory.setSizeThreshold(MEMORY_THRESHOLD);
// 設定臨時儲存目錄
factory.setRepository(new File(System.getProperty("java.io.tmpdir")));
ServletFileUpload upload = new ServletFileUpload(factory);
// 設定最大檔案上傳值
upload.setFileSizeMax(MAX_FILE_SIZE);
// 設定最大請求值 (包含檔案和表單資料)
upload.setSizeMax(MAX_REQUEST_SIZE);
upload.setHeaderEncoding("UTF-8");
// 構造臨時路徑來儲存上傳的檔案
// 這個路徑相對當前應用的目錄
String uploadPath = "/usr/image";
// 如果目錄不存在則建立
File uploadDir = new File(uploadPath);
if (!uploadDir.exists()) {
uploadDir.mkdir();
}
JSONObject jsonRes = null;
String resStr = null;
try {
JSONObject json = new JSONObject();
// 解析請求的內容提取檔案資料
List<FileItem> formItems = upload.parseRequest(request);
if (formItems != null && formItems.size() > 0) {
// 迭代表單資料
for (FileItem item : formItems) {
// 處理不在表單中的欄位
if (item.isFormField()) {
json.put(item.getFieldName(), item.getString("UTF-8"));
}else{
String fileName = new File(item.getName()).getName();
String filePath = uploadPath + File.separator + fileName;
File storeFile = new File(filePath);
// 儲存檔案到硬碟
item.write(storeFile);
json.put(item.getFieldName(),fileName);
}
}
}
//業務處理
//
//
jsonRes = new JSONObject(resStr);
} catch (Exception ex) {
}
PrintWriter out =response.getWriter();
out.println(jsonRes.toString());
out.close();
}
}