我正在尝试将所选图片从gallery中上传到Dropbox。我因为无法恢复运行时异常而被困了几天
我的onActivityResult（）是
if(requestCode == PIC_UPLOAD) {
System.out.println("Reahced 1");
Uri selectedImage = data.getData();
String[] filePathColumn ={MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null); cursor.moveToFirst();
System.out.println("Reahced 2");
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String filePath = cursor.getString(columnIndex);
cursor.close();
Uri imageUri=data.getData();
List<NameValuePair> params = new ArrayList<NameValuePair>(1);
params.add(new BasicNameValuePair("image", imageUri.getPath()));
System.out.println("Reahced 3");
/* String outPath = imageUri.toString(); File outFile = new
File(outPath); FileInputStream fis = new FileInputStream(outFile);
mDBApi.putFileOverwriteRequest("/Pic1", fis, outFile.length(),null);
*/
Uri photoUri = data.getData();
String[] proj = {MediaStore.Images.Media.DATA };
Cursor actualimagecursor = managedQuery(photoUri, proj,null, null, null);
int actual_image_column_index =
actualimagecursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
actualimagecursor.moveToFirst();
String img_path =actualimagecursor.getString(actual_image_column_index);
System.out.println("Image location: " + img_path);
System.out.println("Reached 1");
uploadDropbox(img_path);
}
uploadDropbox正文为：
private void uploadDropbox(String URL) {
// TODO Auto-generated method stub
AppKeyPair appKeys = new AppKeyPair(APP_KEY, APP_SECRET);
AndroidAuthSession session = new AndroidAuthSession(appKeys, ACCESS_TYPE);
mDBApi = new DropboxAPI<AndroidAuthSession>(session);
System.out.println(URL);
System.out.println("Reahced 4");
mDBApi.getSession().startAuthentication(MyCamActivity.this);
System.out.println("Reahced 5");
// AccessTokenPair access = getStoredKeys();
// mDBApi.getSession().setAccessTokenPair(access);
FileInputStream inputStream = null;
try {
File file = new File(URL.toString());
inputStream = new FileInputStream(file);
com.dropbox.client2.DropboxAPI.Entry newEntry = mDBApi.putFile("/testing.txt", inputStream, file.length(), null, null);
Log.i("DbExampleLog", "The uploaded file's rev is: " + newEntry.rev);
} catch (DropboxUnlinkedException e) {
// User has unlinked, ask them to link again here.
Log.e("DbExampleLog", "User has unlinked.");
} catch (DropboxException e) {
Log.e("DbExampleLog", "Something went wrong while uploading.");
} catch (FileNotFoundException e) {
Log.e("DbExampleLog", "File not found.");
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {}
}
}
}
onResume方法正文：
protected void onResume() {
super.onResume();
if (mDBApi.getSession().authenticationSuccessful()) {
try {
// MANDATORY call to complete auth.
// Sets the access token on the session
mDBApi.getSession().finishAuthentication();
AccessTokenPair tokens = mDBApi.getSession().getAccessTokenPair();
// Provide your own storeKeys to persist the access token pair
// A typical way to store tokens is using SharedPreferences
storeKeys(tokens.key, tokens.secret);
} catch (IllegalStateException e) {
Log.i("DbAuthLog", "Error authenticating", e);
}
}
}
private AccessTokenPair getStoredKeys（）{ // TODO自动生成的方法存根
return mDBApi.getSession().getAccessTokenPair();
}
private void storeKeys（String key，String secret）{ // TODO自动生成的方法存根
// Save the access key for later
SharedPreferences prefs = getSharedPreferences(ACCOUNT_PREFS_NAME, 0);
Editor edit = prefs.edit();
edit.putString(ACCESS_KEY_NAME, key);
edit.putString(ACCESS_SECRET_NAME, secret);
edit.commit();
}
的AndroidManifest.xml
<activity
android:name="com.dropbox.client2.android.AuthActivity"
android:launchMode="singleTask"
android:configChanges="orientation|keyboard">
<intent-filter>
<!-- Change this to be db- followed by your app key -->
<data android:scheme="db-MyKey" />
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.BROWSABLE"/>
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity
android:name=".MyCamActivity"
android:label="@string/app_name"
android:screenOrientation="nosensor" android:configChanges="keyboardHidden|orientation"
android:uiOptions="splitActionBarWhenNarrow"
android:clearTaskOnLaunch="true"
>
的 错误的 ** ：
01-23 14:58:00.855: D/dalvikvm(4238): GC_FOR_ALLOC freed 104K, 2% free 12729K/12935K, paused 16ms
01-23 14:58:00.894: I/System.out(4238): Its not null
01-23 14:58:00.901: D/AndroidRuntime(4238): Shutting down VM
01-23 14:58:00.901: W/dalvikvm(4238): threadid=1: thread exiting with uncaught exception (group=0x40a511f8)
01-23 14:58:00.901: E/AndroidRuntime(4238): FATAL EXCEPTION: main
01-23 14:58:00.901: E/AndroidRuntime(4238): java.lang.RuntimeException: Unable to resume activity {cam.pack/cam.pack.MyCamActivity}: java.lang.NullPointerException
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2444)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2472)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1986)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.ActivityThread.access$600(ActivityThread.java:123)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.os.Handler.dispatchMessage(Handler.java:99)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.os.Looper.loop(Looper.java:137)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.ActivityThread.main(ActivityThread.java:4424)
01-23 14:58:00.901: E/AndroidRuntime(4238): at java.lang.reflect.Method.invokeNative(Native Method)
01-23 14:58:00.901: E/AndroidRuntime(4238): at java.lang.reflect.Method.invoke(Method.java:511)
01-23 14:58:00.901: E/AndroidRuntime(4238): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
01-23 14:58:00.901: E/AndroidRuntime(4238): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
01-23 14:58:00.901: E/AndroidRuntime(4238): at dalvik.system.NativeStart.main(Native Method)
01-23 14:58:00.901: E/AndroidRuntime(4238): Caused by: java.lang.NullPointerException
01-23 14:58:00.901: E/AndroidRuntime(4238): at cam.pack.MyCamActivity.onResume(MyCamActivity.java:571)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1154)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.Activity.performResume(Activity.java:4539)
01-23 14:58:00.901: E/AndroidRuntime(4238): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2434)
01-23 14:58:00.901: E/AndroidRuntime(4238): ... 12 more
答案 0 :(得分：0)
我犯了一个错误，我把dropbox会话放在我自己定义的函数uploadDropbox()中，这就是一个错误导致NullPointerException，因为如果我打印mDBApi所以它的NULL。它没有初始化。我们必须将这些行放在onCreate()中，现在它正在工作，图像将在Dropbox的CameraUploads文件夹中上传。
感谢您的评论。