我在从运行时抛出的gallery.String.trim（）null对象引用上传图像时收到空指针异常。
下面我指出了错误行。
logcat的：
02-11 07:00:20.932: E/selectedImageUri(24696) : content://com.android.providers.media.documents/document/image%3A388
02-11 07:00:20.935: E/selectedPath1(24696) : null
02-11 07:00:23.840: E/selectedImageUri(24696) : content://com.android.providers.media.documents/document/image%3A388
02-11 07:00:23.845: E/selectedPath2(24696) : null
02-11 07:00:26.004: E/AndroidRuntime(24696): FATAL EXCEPTION: main
02-11 07:00:26.004: E/AndroidRuntime(24696): Process: com.steve.multipleuploadimage, PID: 24696
02-11 07:00:26.004: E/AndroidRuntime(24696): java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.trim()' on a null object reference
02-11 07:00:26.004: E/AndroidRuntime(24696): at com.steve.multipleuploadimage.MainActivity$3.onClick(MainActivity.java:80)
02-11 07:00:26.004: E/AndroidRuntime(24696): at android.view.View.performClick(View.java:4756)
02-11 07:00:26.004: E/AndroidRuntime(24696): at android.view.View$PerformClick.run(View.java:19749)
02-11 07:00:26.004: E/AndroidRuntime(24696): at android.os.Handler.handleCallback(Handler.java:739)
02-11 07:00:26.004: E/AndroidRuntime(24696): at android.os.Handler.dispatchMessage(Handler.java:95)
02-11 07:00:26.004: E/AndroidRuntime(24696): at android.os.Looper.loop(Looper.java:135)
02-11 07:00:26.004: E/AndroidRuntime(24696): at android.app.ActivityThread.main(ActivityThread.java:5221)
02-11 07:00:26.004: E/AndroidRuntime(24696): at java.lang.reflect.Method.invoke(Native Method)
02-11 07:00:26.004: E/AndroidRuntime(24696): at java.lang.reflect.Method.invoke(Method.java:372)
02-11 07:00:26.004: E/AndroidRuntime(24696): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
02-11 07:00:26.004: E/AndroidRuntime(24696): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
MainActivity.java：
b1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
openGallery(SELECT_FILE1);
}
});
b2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
openGallery(SELECT_FILE2);
}
});
b3.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if(!(selectedPath1.trim().equalsIgnoreCase("NONE")) && !(selectedPath2.trim().equalsIgnoreCase("NONE"))){ ----> 80th line
progressDialog = ProgressDialog.show(MainActivity.this, "", "Uploading files to server.....", false);
Thread thread=new Thread(new Runnable(){
public void run(){
doFileUpload();
runOnUiThread(new Runnable(){
public void run() {
if(progressDialog.isShowing())
progressDialog.dismiss();
}
});
}
});
thread.start();
}else{
Toast.makeText(getApplicationContext(),"Please select two files to upload.", Toast.LENGTH_SHORT).show();
}
}
});
}
public void openGallery(int req_code){
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent,"Select file to upload "), req_code);
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
Uri selectedImageUri = data.getData();
Log.e("selectedImageUri",""+selectedImageUri);
if (requestCode == SELECT_FILE1)
{
selectedPath1 = getPath(selectedImageUri);
Log.e("selectedPath1", ""+selectedPath1);
}
if (requestCode == SELECT_FILE2)
{
selectedPath2 = getPath(selectedImageUri);
Log.e("selectedPath2", ""+selectedPath2);
}
tv.setText("Selected File paths : " + selectedPath1 + "," + selectedPath2);
}
}
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);
}
private void doFileUpload(){
File file1 = new File(selectedPath1);
File file2 = new File(selectedPath2);
String urlString = "http://10.0.2.2/upload_test/upload_media_test.php";
try
{
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(urlString);
FileBody bin1 = new FileBody(file1);
FileBody bin2 = new FileBody(file2);
MultipartEntity reqEntity = new MultipartEntity();
reqEntity.addPart("uploadedfile1", bin1);
reqEntity.addPart("uploadedfile2", bin2);
reqEntity.addPart("user", new StringBody("User"));
post.setEntity(reqEntity);
HttpResponse response = client.execute(post);
resEntity = response.getEntity();
final String response_str = EntityUtils.toString(resEntity);
if (resEntity != null) {
Log.i("RESPONSE",response_str);
runOnUiThread(new Runnable(){
public void run() {
try {
res.setTextColor(Color.GREEN);
res.setText("n Response from server : n " + response_str);
Toast.makeText(getApplicationContext(),"Upload Complete. Check the server uploads directory.", Toast.LENGTH_LONG).show();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
catch (Exception ex){
Log.e("Debug", "error: " + ex.getMessage(), ex);
}
}
任何人都可以帮我解决这个问题。谢谢。
答案 0 :(得分：0)
你的字符串selectedPath2似乎是空的。
请检查：
if(selectedPath2!= null && !selectedPath2.isEmpty())
{
if(!(selectedPath1.trim().equalsIgnoreCase("NONE")) && !(selectedPath2.trim().equalsIgnoreCase("NONE"))){ ----> 80th line
............................ .
}