Android实现上传拍下的照片到服务器

作为一个玩Android的新手，之前一直在玩有关UI的东西，很少接触后端，昨天网上帮同学完成一个项目，要求实现手机调用摄像头拍照，然后预览照片最后还要讲图片上传到服务端。于是就找到了这样一个github上的文档
上传拍下的照片、视频到服务器
这个文档写的非常的清楚，代码也有，不过我这里还是想写点我的分析。

Config这个类，这个类用于保存文件上传所送到的 URL 地址，还有在移动设备中存储图片/视频的目录名称。你可能需要在测试 App 时使用你自己的 URL 地址进行上传操作。上面的链接没有给出Config 的代码，其实也不需要给出因为这里你只需要设置你上传文件的URL的地址就好了。这里我贴出自己的代码。

public static final String FILE_UPLOAD_URL = "http://XXXXXXXXX/fileUpload.php";         // Directory name to store captured images and videos    public static final String IMAGE_DIRECTORY_NAME = "Android File Upload";

FILE_UPLOAD_URL就是你连接后端服务器用的，我这里用的是php，别的行不行我就不知道了，理论上是没问题。

AndroidMultiPartEntity这个类我也没有认真的去分析它，就知道它在进度条的进度增量上有用到。

后面就是MainActivity这个类了，这个类的界面很简单按钮一个就行（因为这里我只需要拍照不需要录像），这里我也把我的代码贴上，虽然没多大区别。

import java.io.File;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Locale;import android.app.Activity;import android.content.Intent;import android.content.pm.PackageManager;import android.net.Uri;import android.os.Bundle;import android.os.Environment;import android.provider.MediaStore;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.Toast;import android.view.View.OnClickListener;public class MainActivity extends Activity {    private static final String TAG = MainActivity.class.getSimpleName();     private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;     private static final int MEDIA_TYPE_IMAGE = 1;     private Uri  fileUri;     private Button btn_take,btn_load;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        btn_take = (Button) findViewById(R.id.btn_take);        btn_load= (Button) findViewById(R.id.btn_load);        btn_take.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                takephoto();            }        });        if(!isDeviceSupportCamera()){            Toast.makeText(getApplicationContext(), "Sorry! Your device doesn't support camera", Toast.LENGTH_LONG).show();            finish();        }    }    //检查设备是否有摄像机    private boolean isDeviceSupportCamera() {        if (getApplicationContext().getPackageManager().hasSystemFeature(               PackageManager.FEATURE_CAMERA)) {                    return true;            } else {                    return false;            }     }    private void takephoto(){        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);        fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);        intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);        // start the image capture Intent        startActivityForResult(intent, CAMERA_CAPTURE_IMAGE_REQUEST_CODE);    }     public Uri getOutputMediaFileUri(int type) {         return Uri.fromFile(getOutputMediaFile(type));     }     protected void onActivityResult(int requestCode, int resultCode, Intent data) {         // if the result is capturing Image         if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {             if (resultCode == RESULT_OK) {                 // successfully captured the image                 // launching upload activity                 Log.e(TAG, "I have finish it");                 launchUploadActivity(true);             } else if (resultCode == RESULT_CANCELED) {                 // user cancelled Image capture                 Toast.makeText(getApplicationContext(),                         "User cancelled image capture", Toast.LENGTH_SHORT)                         .show();             } else {                 // failed to capture image                 Toast.makeText(getApplicationContext(),                         "Sorry! Failed to capture image", Toast.LENGTH_SHORT)                         .show();             }         } else {                 // failed to record video                 Toast.makeText(getApplicationContext(),                         "Sorry! Failed to record video", Toast.LENGTH_SHORT)                         .show();             }     }     private void launchUploadActivity(boolean isImage){         Intent i = new Intent(MainActivity.this, UpLoadActivity.class);         i.putExtra("filePath", fileUri.getPath());         i.putExtra("isImage", isImage);         startActivity(i);         Log.e(TAG, "Did i have finish");     }     private static File getOutputMediaFile(int type) {         // External sdcard location         File mediaStorageDir = new File(                 Environment                         .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),                 Config.IMAGE_DIRECTORY_NAME);         // Create the storage directory if it does not exist         if (!mediaStorageDir.exists()) {             if (!mediaStorageDir.mkdirs()) {                 Log.d(TAG, "Oops! Failed create "                         + Config.IMAGE_DIRECTORY_NAME + " directory");                 return null;             }         }         // Create a media file name         String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",                 Locale.getDefault()).format(new Date());         File mediaFile;         if (type == MEDIA_TYPE_IMAGE) {             mediaFile = new File(mediaStorageDir.getPath() + File.separator                     + "IMG_" + timeStamp + ".jpg");         } else {             return null;         }         return mediaFile;     }}

点击按钮即调用takephoto（）这个函数，这个函数就是请求手机调用摄像头的。当然别忘记在AndroidManifest.xml 中添加相应的权限。
拍照确定保存该照片后，程序直接跳转到UploadAcitvity
因为我们在调用摄像头的时候使用的是startActivityForResult这个函数，这个函数是在你调用摄像头这个Activity完成后去执行onActivityResult（）这个函数，然后根据requestCode和resultCode两个参数决定实现某种功能，在这里若拍照成功，则返回RESULT_OK然后跳转到UploadAcitivity中去。这里我在学习下是怎么保存image的。
我们可以看到takephoto()种有一个变量fileUri，从变量名就看得出是image的路径。好，接下来就是getOutputMediaFileUri和getOutputMediaFile，getOutputMediaFileUri（）函数中就只有一句代码，主要就是fromFile这个函数，这个函数的作用呢是从文件中创建一个URI。该URI的形式是“文件：//”。除’/’编码路径的字符。那么getOutputMediaFile这个函数肯定是将图片以及图片的信息放到保存起来作为一个文件。
好的，最后我们进入UploadAcitvity中去，我们可以在launchUploadActivity（）这个函数中看到，在我们调用UploadAcitvity时还给她传了两个参数，一个是fileUri（图片的路径），一个是isImage（判断它是否是图片）。

package com.qingfeng.imageload;import com.qingfeng.imageload.AndroidMultiPartEntity.ProgressListener;import java.io.File;import java.io.IOException;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpPost;import org.apache.http.entity.mime.content.FileBody;import org.apache.http.entity.mime.content.StringBody;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.util.EntityUtils;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Color;import android.graphics.drawable.ColorDrawable;import android.os.AsyncTask;import android.os.Bundle;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.ImageView;import android.widget.ProgressBar;import android.widget.TextView;import android.widget.Toast;import android.widget.VideoView;public class UploadActivity extends Activity {    // LogCat tag    private static final String TAG = MainActivity.class.getSimpleName();    private ProgressBar progressBar;    private String filePath = null;    private TextView txtPercentage;    private ImageView imgPreview;    private VideoView vidPreview;    private Button btnUpload;    long totalSize = 0;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_upload);        txtPercentage = (TextView) findViewById(R.id.txtPercentage);        btnUpload = (Button) findViewById(R.id.btnUpload);        progressBar = (ProgressBar) findViewById(R.id.progressBar);        imgPreview = (ImageView) findViewById(R.id.imgPreview);        vidPreview = (VideoView) findViewById(R.id.videoPreview);        // Changing action bar background color        getActionBar().setBackgroundDrawable(                new ColorDrawable(Color.parseColor(getResources().getString(                        R.color.action_bar))));        // Receiving the data from previous activity        Intent i = getIntent();        // image or video path that is captured in previous activity        filePath = i.getStringExtra("filePath");        // boolean flag to identify the media type, image or video        boolean isImage = i.getBooleanExtra("isImage", true);        if (filePath != null) {            // Displaying the image or video on the screen            previewMedia(isImage);        } else {            Toast.makeText(getApplicationContext(),                    "Sorry, file path is missing!", Toast.LENGTH_LONG).show();        }        btnUpload.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                // uploading the file to server                new UploadFileToServer().execute();            }        });    }    /** * Displaying captured image/video on the screen * */    private void previewMedia(boolean isImage) {        // Checking whether captured media is image or video        if (isImage) {            imgPreview.setVisibility(View.VISIBLE);            vidPreview.setVisibility(View.GONE);            // bimatp factory            BitmapFactory.Options options = new BitmapFactory.Options();            // down sizing image as it throws OutOfMemory Exception for larger            // images            options.inSampleSize = 8;            final Bitmap bitmap = BitmapFactory.decodeFile(filePath, options);            imgPreview.setImageBitmap(bitmap);        } else {            imgPreview.setVisibility(View.GONE);            vidPreview.setVisibility(View.VISIBLE);            vidPreview.setVideoPath(filePath);            // start playing            vidPreview.start();        }    }    /** * Uploading the file to server * */    private class UploadFileToServer extends AsyncTask<Void, Integer, String> {        @Override        protected void onPreExecute() {            // setting progress bar to zero            progressBar.setProgress(0);            super.onPreExecute();        }        @Override        protected void onProgressUpdate(Integer... progress) {            // Making progress bar visible            progressBar.setVisibility(View.VISIBLE);            // updating progress bar value            progressBar.setProgress(progress[0]);            // updating percentage value            txtPercentage.setText(String.valueOf(progress[0]) + "%");        }        @Override        protected String doInBackground(Void... params) {            return uploadFile();        }        @SuppressWarnings("deprecation")        private String uploadFile() {            String responseString = null;            HttpClient httpclient = new DefaultHttpClient();            HttpPost httppost = new HttpPost(Config.FILE_UPLOAD_URL);            try {                AndroidMultiPartEntity entity = new AndroidMultiPartEntity(                        new ProgressListener() {                            @Override                            public void transferred(long num) {                                publishProgress((int) ((num / (float) totalSize) * 100));                            }                        });                File sourceFile = new File(filePath);                // Adding file data to http body                entity.addPart("image", new FileBody(sourceFile));                // Extra parameters if you want to pass to server                entity.addPart("website",                        new StringBody("www.android.com"));                entity.addPart("email", new StringBody("promisesaybye@gmail.com"));                totalSize = entity.getContentLength();                httppost.setEntity(entity);                // Making server call                HttpResponse response = httpclient.execute(httppost);                HttpEntity r_entity = response.getEntity();                int statusCode = response.getStatusLine().getStatusCode();                if (statusCode == 200) {                    // Server response                    responseString = EntityUtils.toString(r_entity);                } else {                    responseString = "Error occurred! Http Status Code: "                            + statusCode;                }            } catch (ClientProtocolException e) {                responseString = e.toString();            } catch (IOException e) {                responseString = e.toString();            }            return responseString;        }        @Override        protected void onPostExecute(String result) {            Log.e(TAG, "Response from server: " + result);            // showing the server response in an alert dialog            showAlert(result);            super.onPostExecute(result);        }    }    /** * Method to show alert dialog * */    private void showAlert(String message) {        AlertDialog.Builder builder = new AlertDialog.Builder(this);        builder.setMessage(message).setTitle("Response from Servers")                .setCancelable(false)                .setPositiveButton("OK", new DialogInterface.OnClickListener() {                    public void onClick(DialogInterface dialog, int id) {                        // do nothing                    }                });        AlertDialog alert = builder.create();        alert.show();    }}

上面是有关UploadActivity的代码。最重要的肯定是上传到服务器的编写了—-UploadFileToServer（）里面的doInBackground（）这个函数中的uploadFile。里面有个addPart我去官网搜都没搜到，若有大神知道还望指点~

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