Question

我想在我的应用程序中添加图像上传器，我可以从图像文件夹中选择一个图像，但是当我选择图像时，图像路径只显示为“null”，当我点击上传时，我得到这个错误：

BitmapFactory：无法解码流：java.lang.NullPointerException：

这是我的代码：

package com.test.mysqltest;

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class UploadToServer extends Activity implements OnClickListener{

private TextView messageText;
private Button uploadButton, btnselectpic;
private ImageView imageview;
private int serverResponseCode = 0;
private ProgressDialog dialog = null;

private String upLoadServerUri = null;
private String imagepath=null;
@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_upload_to_server);

    uploadButton = (Button)findViewById(R.id.uploadButton);
    btnselectpic = (Button)findViewById(R.id.button_selectpic);
    messageText  = (TextView)findViewById(R.id.messageText);
    imageview = (ImageView)findViewById(R.id.imageView_pic);

    btnselectpic.setOnClickListener(this);
    uploadButton.setOnClickListener(this);
    upLoadServerUri = "http://www.eywow.com/webservice/UploadToServer.php";
    ImageView img= new ImageView(this);

}


@Override
public void onClick(View arg0) {
    if(arg0==btnselectpic)
    {
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(Intent.createChooser(intent, "Complete action using"), 1);
    }
    else if (arg0==uploadButton) {

        dialog = ProgressDialog.show(UploadToServer.this, "", "Uploading file...", true);
        messageText.setText("uploading started.....");
        new Thread(new Runnable() {
            public void run() {

                uploadFile(imagepath);

            }
        }).start();
    }

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == 1 && resultCode == RESULT_OK) {
        //Bitmap photo = (Bitmap) data.getData().getPath();

        Uri selectedImageUri = data.getData();
        imagepath = getPath(selectedImageUri);
        Bitmap bitmap=BitmapFactory.decodeFile(imagepath);
        imageview.setImageBitmap(bitmap);
        messageText.setText("Uploading file path:" +imagepath);

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




public int uploadFile(String sourceFileUri) {


    String fileName = sourceFileUri;

    HttpURLConnection conn = null;
    DataOutputStream dos = null;
    String lineEnd = "\r\n";
    String twoHyphens = "--";
    String boundary = "*****";
    int bytesRead, bytesAvailable, bufferSize;
    byte[] buffer;
    int maxBufferSize = 1 * 1024 * 1024;
    File sourceFile = new File(sourceFileUri);

    if (!sourceFile.isFile()) {

        dialog.dismiss();

        Log.e("uploadFile", "Source File not exist :"+imagepath);

        runOnUiThread(new Runnable() {
            public void run() {
                messageText.setText("Source File not exist :"+ imagepath);
            }
        });

        return 0;

    }
    else
    {
        try {

            // open a URL connection to the Servlet
            FileInputStream fileInputStream = new FileInputStream(sourceFile);
            URL url = new URL(upLoadServerUri);

            // Open a HTTP  connection to  the URL
            conn = (HttpURLConnection) url.openConnection();
            conn.setDoInput(true); // Allow Inputs
            conn.setDoOutput(true); // Allow Outputs
            conn.setUseCaches(false); // Don't use a Cached Copy
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("ENCTYPE", "multipart/form-data");
            conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
            conn.setRequestProperty("uploaded_file", fileName);

            dos = new DataOutputStream(conn.getOutputStream());

            dos.writeBytes(twoHyphens + boundary + lineEnd);
            dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
                    + fileName + "\"" + lineEnd);

            dos.writeBytes(lineEnd);

            // create a buffer of  maximum size
            bytesAvailable = fileInputStream.available();

            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];

            // read file and write it into form...
            bytesRead = fileInputStream.read(buffer, 0, bufferSize);

            while (bytesRead > 0) {

                dos.write(buffer, 0, bufferSize);
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);

            }

            // send multipart form data necesssary after file data...
            dos.writeBytes(lineEnd);
            dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

            // Responses from the server (code and message)
            serverResponseCode = conn.getResponseCode();
            String serverResponseMessage = conn.getResponseMessage();

            Log.i("uploadFile", "HTTP Response is : "
                    + serverResponseMessage + ": " + serverResponseCode);

            if(serverResponseCode == 200){

                runOnUiThread(new Runnable() {
                    public void run() {
                        String msg = "File Upload Completed.\n\n See uploaded file here : \n\n"
                                +" F:/wamp/wamp/www/uploads";
                        messageText.setText(msg);
                        Toast.makeText(UploadToServer.this, "File Upload Complete.", Toast.LENGTH_SHORT).show();
                    }
                });
            }

            //close the streams //
            fileInputStream.close();
            dos.flush();
            dos.close();

        } catch (MalformedURLException ex) {

            dialog.dismiss();
            ex.printStackTrace();

            runOnUiThread(new Runnable() {
                public void run() {
                    messageText.setText("MalformedURLException Exception : check script url.");
                    Toast.makeText(UploadToServer.this, "MalformedURLException", Toast.LENGTH_SHORT).show();
                }
            });

            Log.e("Upload file to server", "error: " + ex.getMessage(), ex);
        } catch (Exception e) {

            dialog.dismiss();
            e.printStackTrace();

            runOnUiThread(new Runnable() {
                public void run() {
                    messageText.setText("Got Exception : see logcat ");
                    Toast.makeText(UploadToServer.this, "Got Exception : see logcat ", Toast.LENGTH_SHORT).show();
                }
            });
            Log.e("Upload file to server Exception", "Exception : "  + e.getMessage(), e);
        }
        dialog.dismiss();
        return serverResponseCode;

    } // End else block
}


}

有任何想法如何解决这个问题？

Answer 1

现在效果更好，图片预览第一次正常工作，但我仍然没有找到合适的文件路径上传它：Image uploader

这是我更新的代码：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent  data) {



    if (requestCode == 1 && resultCode == RESULT_OK) {
        //Bitmap photo = (Bitmap) data.getData().getPath();


        Uri selectedImageUri = data.getData();

        try { Bitmap bitmap=BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImageUri));


            imageview.setImageBitmap(bitmap);
            messageText.setText("Uploading file path:" +imagepath);

        } catch(IOException ie) {

            messageText.setText("Error");
        }


    }
}

Answer 2

直接在onActivityResult（）

中使用这行代码

Bitmap bitmap=BitmapFactory.decodeStream(getContentResolver().openInputStream(targetUri));

这应该有用。

编辑：试着找到我自己上面写过的兄弟：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        if (requestCode == 1 && resultCode == RESULT_OK) {
            ...
            Bitmap bitmap=BitmapFactory.decodeStream(getContentResolver().openInputStream(targetUri));
            imageview.setImageBitmap(bitmap);
            ...
        }
    }

BitmapFactory：无法解码流 - null

2 个答案: