Java 使用Android智能手机通过FTP上传文件

我正试图用我自己的应用程序通过FTP从我的Android智能手机上传一个文件。我已经完成了一个代码，但它不工作。相反，它在Logact中抛出异常。我希望你能帮助我

旧图书馆：

我的代码：

package com.florian.ftpupload;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.SocketException;

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;

import com.florian.ftpupload.R;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

public class UploadActivity extends Activity{

public static final String TAG = "Contacts";

public String host = "<serverip>";
public String username = "<username>";
public String password = "<password>";
public String database = "test.txt";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_upload);


    Thread t = new Thread(new Runnable(){
        @Override
        public void run(){
            try {
                DatabaseUpload();
            } catch (SocketException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    });
    t.start();
    Log.i(TAG, "thread started");


}

protected void DatabaseUpload() throws SocketException, IOException {
    FTPClient ftp = new FTPClient();
      ftp.connect(host);
      int reply = ftp.getReplyCode();

      if (!FTPReply.isPositiveCompletion(reply)){
        Toast.makeText(getApplicationContext(), "FTP server refused connection.", Toast.LENGTH_SHORT).show();
      }

      ftp.login(username, password);
      ftp.setFileType(FTP.BINARY_FILE_TYPE);
      ftp.enterLocalPassiveMode();

      InputStream fis = new FileInputStream(database);
      ftp.storeFile("test.txt", fis);
      fis.close();

      ftp.logout();
      ftp.disconnect();
}
}    

我希望你能理解我的问题；）

---

~Florian

您在

org.apache.commons.net.ftp.FTPClient

类上有一个

NoClassDefFoundError

。您确定在项目中正确导入了库吗？我认为我做得对@Ace_McIntosh您能告诉我如何正确导入吗？您使用的是Gradle吗？在这种情况下，您应该在build.gradle应用程序文件

compile'commons-net:commons-net:3.4'

中具有此依赖关系。查看Maven存储库，这是导入

org.apache.commons.net.ftp
包中的类所需的包：。或者，您可以将库的.jar文件添加到项目中。该.jar文件添加到引用库和libs文件夹中@Ace_McIntoshi如果导入了库，那么我猜在构建过程中出现了一些错误（可能是生成的.dex文件出现了一些问题–在运行时，包似乎不存在），可能是构建配置中出现了一些错误。对于初学者（您可能已经尝试过了，如果没有帮助，可能是配置中的问题），您可以尝试Build-Clean项目（假设您使用的是Android Studio）或
gradle Clean
，看看这是否只是一个一次性错误。
D/Genymotion(   56): Received Ping
I/ActivityManager(  366): START u0 {act=android.intent.action.MAIN cat=    [android.
intent.category.LAUNCHER] flg=0x10200000   cmp=com.florian.ftpupload/.UploadActivi
ty} from pid 586
D/dalvikvm(  366): GC_CONCURRENT freed 805K, 16% free 7450K/8816K, paused     1ms+2m
s, total 20ms
I/ActivityManager(  366): Start proc com.florian.ftpupload for activity     com.flor
ian.ftpupload/.UploadActivity: pid=1421 uid=10051 gids={50051, 1028}
I/qtaguid (  366): Failed write_ctrl(s 1 10051) res=-1 errno=1
W/NetworkManagementSocketTagger(  366): setKernelCountSet(10051, 1) failed   with
errno -1
E/dalvikvm( 1421): Could not find class     'org.apache.commons.net.ftp.FTPClient',
referenced from method com.florian.ftpupload.UploadActivity.DatabaseUpload
W/dalvikvm( 1421): VFY: unable to resolve new-instance 1557   (Lorg/apache/commons
/net/ftp/FTPClient;) in Lcom/florian/ftpupload/UploadActivity;
D/dalvikvm( 1421): VFY: replacing opcode 0x22 at 0x0000
D/dalvikvm( 1421): DexOpt: unable to opt direct call 0x2a97 at 0x02 in     Lcom/flor
ian/ftpupload/UploadActivity;.DatabaseUpload
I/Contacts( 1421): thread started
W/dalvikvm( 1421): threadid=10: thread exiting with uncaught exception     (group=0x
a614c908)
E/AndroidRuntime( 1421): FATAL EXCEPTION: Thread-122
E/AndroidRuntime( 1421): java.lang.NoClassDefFoundError:     org.apache.commons.net.
ftp.FTPClient
E/AndroidRuntime( 1421):        at     com.florian.ftpupload.UploadActivity.Database
Upload(UploadActivity.java:55)
E/AndroidRuntime( 1421):        at   com.florian.ftpupload.UploadActivity$1.run(Up
loadActivity.java:40)
E/AndroidRuntime( 1421):        at java.lang.Thread.run(Thread.java:856)
W/ActivityManager(  366):   Force finishing activity  com.florian.ftpupload/.Uplo
adActivity
D/libEGL  ( 1421): loaded /system/lib/egl/libEGL_genymotion.so
D/        ( 1421): HostConnection::get() New Host Connection established   0xb7b1a
f98, tid 1421
D/libEGL  ( 1421): loaded /system/lib/egl/libGLESv1_CM_genymotion.so
D/libEGL  ( 1421): loaded /system/lib/egl/libGLESv2_genymotion.so
I/ActivityManager(  366): START u0 {act=android.intent.action.MAIN cat=    [android.
intent.category.LAUNCHER] flg=0x10200000     cmp=com.florian.ftpupload/.UploadActivi
ty} from pid 586
W/EGL_genymotion( 1421): eglSurfaceAttrib not implemented
D/OpenGLRenderer( 1421): Enabling debug mode 0
I/Contacts( 1421): thread started
W/dalvikvm( 1421): threadid=11: thread exiting with uncaught exception    (group=0x
a614c908)
I/Process ( 1421): Sending signal. PID: 1421 SIG: 9
I/qtaguid (  366): Failed write_ctrl(s 0 10051) res=-1 errno=1
W/NetworkManagementSocketTagger(  366): setKernelCountSet(10051, 0) failed   with
errno -1
I/ActivityManager(  366): Process com.florian.ftpupload (pid 1421) has died.
I/WindowState(  366): WIN DEATH: Window{533f06e4 u0     com.florian.ftpupload/com.fl
orian.ftpupload.UploadActivity}
W/ActivityManager(  366): Force removing ActivityRecord{5348c488 u0     com.florian.
ftpupload/.UploadActivity}: app died, no saved state
I/WindowState(  366): WIN DEATH: Window{5343b134 u0     com.florian.ftpupload/com.fl
orian.ftpupload.UploadActivity}
W/EGL_genymotion(  586): eglSurfaceAttrib not implemented
W/InputMethodManagerService(  366): Window already focused, ignoring focus   gain
of: com.android.internal.view.IInputMethodClient$Stub$Proxy@53330148   attribute=n
ull, token = android.os.BinderProxy@533c6a54
D/Genymotion(   56): Received Ping