• 在fragment中实现Android上传图片至本地JavaWeb服务器


    服务器端:

    需要一个接受文件的servlet,以及导入两个包:commons-fileupload-1.3.1.jar 和 commons-io-2.4.jar

    import java.io.File;  
    import java.io.FileOutputStream;  
    import java.io.IOException;  
    import java.io.InputStream;  
    import java.io.PrintWriter;  
    import java.util.List;  
     
    import javax.servlet.ServletException;  
    import javax.servlet.http.HttpServlet;  
    import javax.servlet.http.HttpServletRequest;  
    import javax.servlet.http.HttpServletResponse;  
     
    import org.apache.commons.fileupload.FileItem;  
    import org.apache.commons.fileupload.FileItemFactory;  
    import org.apache.commons.fileupload.disk.DiskFileItemFactory;  
    import org.apache.commons.fileupload.servlet.ServletFileUpload;  
     
    public class Upload extends HttpServlet  
    {  
        protected void service(HttpServletRequest request,  
                HttpServletResponse response) throws ServletException, IOException{  
            try{  
                request.setCharacterEncoding("UTF-8"); // 设置处理请求参数的编码格式  
                response.setContentType("text/html;charset=UTF-8"); // 设置Content-Type字段值  
                PrintWriter out = response.getWriter();  
             
                //下面的代码开始使用Commons-UploadFile组件处理上传的文件数据  
                FileItemFactory factory = new DiskFileItemFactory(); // 建立FileItemFactory对象  
                ServletFileUpload upload = new ServletFileUpload(factory);  
                //分析请求,并得到上传文件的FileItem对象  
                List<FileItem> items = upload.parseRequest(request);  
                //从web.xml文件中的参数中得到上传文件的路径  
                String uploadPath = "E:\A_HW\";  
                File file = new File(uploadPath);  
                if (!file.exists())  
                {  
                    file.mkdir();  
                }  
                String filename = ""; // 上传文件保存到服务器的文件名  
                InputStream is = null; // 当前上传文件的InputStream对象  
                //循环处理上传文件  
                for (FileItem item : items) {
                    //处理普通的表单域  
                    if (item.isFormField())  
                    {  
                    if (item.getFieldName().equals("imageFile"))  //图片文件的name
                    {  
                    //如果新文件不为空,将其保存在filename中  
                    if (!item.getString().equals(""))  
                    filename = item.getString("UTF-8");  
                    }  
                }  
                //处理上传文件  
                else if (item.getName() != null && !item.getName().equals(""))  
                {  
                    //从客户端发送过来的上传文件路径中截取文件名  
                    filename = item.getName().substring(  
                    item.getName().lastIndexOf("\") + 1);  
                    is = item.getInputStream(); // 得到上传文件的InputStream对象  
                }  
                }  
                //将路径和上传文件名组合成完整的服务端路径  
                filename = uploadPath + filename;  
                //如果服务器已经存在和上传文件同名的文件,则输出提示信息  
                if (new File(filename).exists())  
                {  
                    new File(filename).delete();  
                }  
                //开始上传文件  
                if (!filename.equals(""))  
                {  
                    //用FileOutputStream打开服务端的上传文件  
                    FileOutputStream fos = new FileOutputStream(filename);  
                    byte[] buffer = new byte[8192]; // 每次读8K字节  
                    int count = 0;  
                    //开始读取上传文件的字节,并将其输出到服务端的上传文件输出流中  
                    while ((count = is.read(buffer)) > 0)  
                    {  
                        fos.write(buffer, 0, count); // 向服务端文件写入字节流  
                    }  
                    fos.close(); // 关闭FileOutputStream对象  
                    is.close(); // InputStream对象  
                    out.println("文件上传成功!");  
                }  
            }catch (Exception e)  
            {  
            e.printStackTrace();
            }  
        }
    }  
    注意:imageFile要和之后Android端名字的对应

    客户端:

     我是直接通过拍照获取的图片,所以首先获取图片的位置

    private void doTakePhoto() {
            Intent intent = new Intent();
            // 指定开启系统相机的Action
            intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
            intent.addCategory(Intent.CATEGORY_DEFAULT);
            String time = String.valueOf(System.currentTimeMillis());
            // 根据文件地址创建文件
            File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath()
                    + "/M2_test/" + time + ".jpg");
            Log.i("Environment_path", Environment.getExternalStorageDirectory().getAbsolutePath());
            file.getParentFile().mkdirs();
            if (file.exists()) {
                file.delete();
            }
            // 把文件地址转换成Uri格式
            Uri uri2 = Uri.fromFile(file);
            Uri uri = FileProvider.getUriForFile(getContext(), "com.f.myapplication", file);
            //添加权限
            Log.i("uri",uri.toString());
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); //临时授权
            intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
            startActivityForResult(intent, REQUEST_CAMERA);
    
    
            String imagePath = Environment.getExternalStorageDirectory().getAbsolutePath()
                    + "/M2_test/" + time + ".jpg";
    
            imageCheck(uri2,imagePath);
    
            iniLocationMap();
    
    //        uploadImage(imagePath);
        }

    获取到的图片进行查看,通过bundle传递image的uri

    private void imageCheck(Uri uri,String img) {
    
            String imagepath = uri.toString();
            Image_check image_check = new Image_check();
            Bundle bundle = new Bundle();
            bundle.putString("imagepath", imagepath);
            bundle.putString("img",img);
            image_check.setArguments(bundle);
            ft.replace(R.id.fragment_content,image_check);  //这个是我fragment替换
            ft.addToBackStack(null);
            ft.commit();
        }
    Image_check是一个Fragment可以查看图片并通过点击按钮实现上传文件(需要点击预览图片,获取到图片位置,才能上传图片)

    public class Image_check  extends Fragment {
    
        private EditText et_beizhu;
        private Button btn_upload;
        private Button btn_look_pic;
        private ImageView iv;
        private FragActivity_Map fragActivity_map;
        String imagepath="";
        String img;
        private FragmentManager fm;
        private FragmentTransaction ft;
        public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.image_check, container, false);
            fm = getFragmentManager();
            ft = fm.beginTransaction();
            fragActivity_map=new FragActivity_Map();
            iv=view.findViewById(R.id.imageView);
            btn_upload= view.findViewById(R.id.btn_upload);
            btn_look_pic= view.findViewById(R.id.btn_look_pic);
            if (getArguments() != null) {
                imagepath = getArguments().getString("imagepath");
                Log.i("image_check_image",imagepath);
            }
    
            btn_look_pic.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    iv.setImageURI( Uri.parse(imagepath) );
                }
            });
            btn_upload.setOnClickListener(new View.OnClickListener() {
                @Override
    
                public void onClick(View v) {
                    uploadImage(imagepath);
                    FragActivity_Map frag_map = new FragActivity_Map();
                    Bundle bundle = new Bundle();
                    bundle.putString("result_image", "ok_upload");
                    frag_map.setArguments(bundle);
                    fm.beginTransaction().hide(Image_check.this).show(fragActivity_map).commit();
    //                ft.replace(R.id.fragment_content,frag_map);
                    ft.addToBackStack(null);
                    ft.commit();
                }
            });
    
    
            return view;
        }
    
        //线程上传图片
        private void uploadImage(String imagePath) {
            Log.i("start upload", "start upload");
            Log.i("start upload_path", "imagePath" + imagePath);
            NetworkTask networkTask = new NetworkTask();
            networkTask.execute(imagePath);
        }
    
        public static Image_check newInstance(String text) {
            Image_check fragment = new Image_check();
            Bundle bundle = new Bundle();
            bundle.putString("imagepath", text);
            fragment.setArguments(bundle);
            return fragment;
        }
    }
    
    
    NetworkTask 是一个实现连接javaweb服务器的线程并调用上传文件的工具类 UploadUtil
    class NetworkTask extends AsyncTask<String, Integer, String> {
    // 这里就是JavaWeb服务器地址,servlet
        private final String ServerURL="http://192.168.1.105:8080/File_upload/Upload";
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }
    
        @Override
        protected String doInBackground(String... params) {
    //        return doPost(params[0]);
            String uri = (params[0]);
            Uri u=Uri.parse((String) uri);
            File file = new File(u.getPath());
            return UploadUtil.uploadFile(file, ServerURL);
        }
        @Override
        protected void onPostExecute(String result) {
            if (UploadUtil.SUCCESS.equalsIgnoreCase(result)) {
                Log.i("上传结果", "上传成功 ");
            } else {
                Log.i("上传结果", "上传失败 ");
            }
        }
    }
    UploadUtil工具类(啊哈,网上找的)
    
    
    public class UploadUtil {
        private static final int TIME_OUT = 10 * 10000000;   //超时时间
        private static final String CHARSET = "utf-8"; //设置编码
        public static final String SUCCESS = "1";
        public static final String FAILURE = "0";
    
        public static String uploadFile(File file, String RequestURL) {
            String BOUNDARY = UUID.randomUUID().toString();  //边界标识   随机生成
            String PREFIX = "--", LINE_END = "
    ";
    
            try {
                URL url = new URL(RequestURL);
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setReadTimeout(TIME_OUT);
                conn.setConnectTimeout(TIME_OUT);
                conn.setDoInput(true);  //允许输入流
                conn.setDoOutput(true); //允许输出流
                conn.setUseCaches(false);  //不允许使用缓存
                conn.setRequestMethod("POST");  //请求方式
                conn.setRequestProperty("Charset", CHARSET);  //设置编码
                conn.setRequestProperty("connection", "keep-alive");
                conn.setRequestProperty("Content-Type", "multipart/form-data" + ";boundary=" + BOUNDARY);
                if (file != null) {
                    OutputStream outputSteam = conn.getOutputStream();
                    DataOutputStream dos = new DataOutputStream(outputSteam);
                    StringBuffer sb = new StringBuffer();
                    sb.append(PREFIX);
                    sb.append(BOUNDARY);
                    sb.append(LINE_END);
                    /**
                     * 这里重点注意:
                     * name里面的值为服务器端需要key   只有这个key 才可以得到对应的文件
                     * filename是文件的名字,包含后缀名的   比如:abc.png
                     */
    
                    Log.i("file.getName()",file.getName());
                    sb.append("Content-Disposition: form-data; name="imageFile"; filename="" + file.getName() + """ + LINE_END);
                    sb.append("Content-Type: application/octet-stream; charset=" + CHARSET + LINE_END);
                    sb.append(LINE_END);
                    dos.write(sb.toString().getBytes());
                    InputStream is = new FileInputStream(file);
                    byte[] bytes = new byte[1024];
                    int len = 0;
                    while ((len = is.read(bytes)) != -1) {
                        dos.write(bytes, 0, len);
                    }
                    is.close();
                    dos.write(LINE_END.getBytes());
                    byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINE_END).getBytes();
                    dos.write(end_data);
                    dos.flush();
                    dos.close();
                    /**
                     * 获取响应码  200=成功
                     * 当响应成功,获取响应的流
                     */
                    int res = conn.getResponseCode();
                    Log.e("response code", "response code:" + res);
                    if (res == 200) {
                        return SUCCESS;
                    }
                }
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return FAILURE;
        }
    }
    
    




    当然当中遇到了很多问题,必须要仔仔细细看错误提示啊
    注意
      • 开了Tomcat服务器后,要关闭电脑的防火墙,要不然可能连接不上
     
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  • 原文地址:https://www.cnblogs.com/Nora-F/p/9011746.html
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