Question

我想将图片上传到我的amazon s3服务器。要做到这一点，我需要制作一个我要发送的图像文件但不知何故它不起作用：

按钮选择图像：

//When clicked on addimage
        addImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // To open up a gallery browser
                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);
            }

点击图库中的图片时：

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == PICK_IMAGE && resultCode == Activity.RESULT_OK && null != data) {
        urimg = data.getData();

         String path = getPath(urimg);
        //create file of image to upload
         images3 = new File(path);
    }
}
        });

getPath方法：

public String getPath(Uri uri) {
        if( uri == null ) {
            return null;
        }
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = getActivity().getContentResolver().query(uri, projection, null, null, null);
        if( cursor != null ){
            int column_index = cursor
                    .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }
        return uri.getPath();
    }

我收到此错误：

12-05 01:37:13.857  30611-30611/com.laurenswuyts.witpa E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.laurenswuyts.witpa, PID: 30611
    java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=65537, result=-1, data=Intent { dat=content://com.android.providers.media.documents/document/image:3000 flg=0x1 }} to activity {com.laurenswuyts.witpa/com.laurenswuyts.witpa.Activities.Events.AddEventActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'char[] java.lang.String.toCharArray()' on a null object reference
            at android.app.ActivityThread.deliverResults(ActivityThread.java:3539)
            at android.app.ActivityThread.handleSendResult(ActivityThread.java:3582)
            at android.app.ActivityThread.access$1300(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1327)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'char[] java.lang.String.toCharArray()' on a null object reference
            at java.io.File.fixSlashes(File.java:185)
            at java.io.File.<init>(File.java:134)

Answer 1

如果要保存图像，请使用此类保存图像

import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Environment;
import android.util.Log;

public class SaveImageIntoDrawable {

    public static String savedImagePath = "" ;

    public static Bitmap drawableToBitmap (Drawable drawable) {
        if (drawable instanceof BitmapDrawable) {
            return ((BitmapDrawable)drawable).getBitmap();
        }

        Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap); 
        drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        drawable.draw(canvas);

        return bitmap;
    }

    public static void saveBitmapIntoDrawable(Bitmap bitmap, Context object) {
        try {

            String timeStamp = new SimpleDateFormat("ddMMyyyy_HHmm").format(new Date());

            savedImagePath = Environment.getExternalStorageDirectory() + "/imagename"+timeStamp+".png" ;

            FileOutputStream out = new FileOutputStream(savedImagePath);
            Log.i(object.getFilesDir().getAbsolutePath(), "complete-path");

            bitmap.compress(Bitmap.CompressFormat.PNG, 90, out);
            out.close();
        } catch (Exception err) {
            err.printStackTrace();
            Log.i("Error in SaveImageIntoDrawable ", "Error");
        }
    }   
}

并使用此课程发布您的图片：

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Dictionary;
import java.util.Enumeration;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.BufferedHttpEntity;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntity;
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.json.JSONObject;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.util.Log;

import com.secondhandbooks.util.ConvertStreamIntoString;
import com.secondhandbooks.util.SaveImageIntoDrawable;

public abstract class BaseAsync_Post extends AsyncTask<String, String, InputStream>
{

    Context context ;
    private HttpPost httppost;
    String url ;
    Dictionary<String, String> dictionary ;


    public BaseAsync_Post(String url , Dictionary<String, String> dictionary, Context context) {
        this.url = url ;
        this.dictionary = dictionary;
        this.context = context ;

        Enumeration<String> enumeration = dictionary.keys() ;


        showLogs("constructor") ;

        while ( enumeration.hasMoreElements() )
        {
            showLogs( enumeration.nextElement() ) ;
        }
    }

    @Override
    abstract protected void onPreExecute() ;
    @Override
    abstract protected void onPostExecute(InputStream result) ;

    @Override
    protected InputStream doInBackground(String... params) {
        // TODO Auto-generated method stub
        // TODO Auto-generated method stub
        InputStream is = null;

        HttpClient httpclient = new DefaultHttpClient();

        httppost = new HttpPost(url);

        MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);

        try 
        {   
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(50);

            Enumeration<String> enumeration = dictionary.keys() ;

            while ( enumeration.hasMoreElements() )
            {
                String key = enumeration.nextElement() ;

                if ( key.equals("file") )
                {
                    final File file = new File(SaveImageIntoDrawable.savedImagePath);

                    if ( file.isFile() )
                    {
                        showLogs("is file");
                    }
                    else
                    {
                        showLogs("no-file");
                    }

                    FileBody fb = new FileBody(file);
                    entity.addPart(key, fb);                        
                }
                else
                {
                    entity.addPart(key, new StringBody(dictionary.get(key)));
                }
            }

            httppost.setEntity(entity);

            HttpResponse response = httpclient.execute(httppost);

            HttpEntity entity1 = response.getEntity();

            BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity1);

            is = bufHttpEntity.getContent();

        } catch (ClientProtocolException e) {
            e.printStackTrace();
            showLogs("ClientProtocolException");
        } catch (IOException e) {
            e.printStackTrace();
            showLogs("IOException");
        }

        return is;
    }

    public String getString(JSONObject json, String TAG) {
        String returnParseData = "";

        try {
            Object aObj = json.get(TAG);
            if (aObj instanceof Boolean) {
                returnParseData = Boolean.toString(json.getBoolean(TAG));
            } else if (aObj instanceof Integer) {
                returnParseData = Integer.toString(json.getInt(TAG));
            } else if (aObj instanceof String) {
                returnParseData = json.getString(TAG);
            } else {
                returnParseData = json.getString(TAG);
            }
        } catch (Exception err) {
            err.printStackTrace();
            returnParseData = "";
        }

        return returnParseData;
    }

    public String getIntintoString(JSONObject json, String TAG) {
        int returnParseData = -1;

        try {
            returnParseData = json.getInt(TAG) ;
        } catch (Exception err) {
            err.printStackTrace();
            returnParseData = -1;
        }

        return Integer.toString(returnParseData) ;
    }

    public void showLogs ( String msg )
    {
        Log.e("HTTP-POST", msg) ;
    }

}

从那里下载httpmime包：http://www.java2s.com/Code/Jar/h/Downloadhttpmime42jar.htm

创建图像文件，android

1 个答案: