android运行时错误使用zxing条形码API，无法在API中找到类
我正在使用（zxing 2.2 API＆amp; its core.jar）编写车辆条形码扫描仪活动。我在开始之前就开始测试功能了。
尝试启动活动时，我遇到“运行时错误”。
实际错误代码段： 10-08 04：36：49.308：E / dalvikvm（780）：找不到类com.toyota.toyotaownerspoc.barcode.ScanVinFromBarcodeActivity.cameraBytesToBinaryBitmap引用的类'com.google.zxing.RGBLuminanceSource' -08 04：36：49.326：E / dalvikvm（780）：找不到类com.toyota.toyotaownerspoc.barcode.ScanVinFromBarcodeActivity.decodeBitmapToString
活动（ScanVinFromBarcodeActivity）在此之后崩溃。
下面的类实际上是通过Eclipse在我的“ScanVinFromBarcodeActivity）”活动中解决的，当我编写代码并编译时，但在运行时找不到
com.google.zxing.MultiFormatReader //在运行时未找到 com.google.zxing.RGBLuminanceSource //在运行时未找到
1）“服务”活动，其中包含启动扫描仪活动的按钮：
package com.toyota.toyotaownerspoc.service;
import com.toyota.toyotaownerspoc.R;
import com.toyota.toyotaownerspoc.barcode.ScanVinFromBarcodeActivity;
import com.toyota.toyotaownerspoc.nearby.Nearby;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class Service extends Activity {
private View scanVinButton = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_service);
scanVinButton = findViewById(R.id.scanVinButton);
scanVinButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(v.getContext(),
ScanVinFromBarcodeActivity.class);
startActivity(i);
}
});
}
}
2）服务活动的布局：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".Service" >
<Button
android:id="@+id/scanVinButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="16dp"
android:text="Scan VIN" />
</RelativeLayout>
现在对具有运行时错误的实际活动＆amp;崩溃
3）实际的“ScanVinFromBarcodeActivity”活动，其中包含条形码扫描仪＆amp; （使用zxing 2.2 liberary＆amp; core.jar）：
package com.toyota.toyotaownerspoc.barcode;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.ChecksumException;
import com.google.zxing.FormatException;
import com.google.zxing.MultiFormatReader; //found via import at compile time, however was found at run time
import com.google.zxing.NotFoundException;
import com.google.zxing.RGBLuminanceSource;//found via import at compile time, however was found at run time
import com.google.zxing.Reader;
import com.google.zxing.Result;
import com.google.zxing.common.HybridBinarizer;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import com.toyota.toyotaownerspoc.R;
public class ScanVinFromBarcodeActivity extends Activity {
private Camera camera;
private int cameraId = 0;
private TextView VINtext = null;
private View scanButton = null;
// bitmap from camera
private Bitmap bmpOfTheImageFromCamera = null;
PictureCallback jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] imgData, Camera camera) {
// get the bitmap from camera imageData
bmpOfTheImageFromCamera = BitmapFactory.decodeByteArray(imgData, 0,
imgData.length);
BinaryBitmap bitmap = null;
if (bmpOfTheImageFromCamera != null) {
// convert bitmap to binary bitmap
bitmap = cameraBytesToBinaryBitmap(bmpOfTheImageFromCamera);
if (bitmap != null) {
// decode the VIN
String VIN = decodeBitmapToString(bitmap);
Log.d("ClassScanViewBarcodeActivity , scanButton.setOnClickListener(): ",
VIN);
VINtext.setText(VIN);
} else {
Log.d("ClassScanViewBarcodeActivity , scanButton.setOnClickListener(): bitmap=",
String.valueOf(bitmap));
}
} else {
Log.d("ClassScanViewBarcodeActivity , scanButton.setOnClickListener(): bmpOfTheImageFromCamera = ",
String.valueOf(bmpOfTheImageFromCamera));
}
}
};// jpegCallback implementation
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_barcode_vin_scanner);
// do we have any camera's on this device
// check for back camera
if (!getPackageManager()
.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
Toast.makeText(this, "No camera on this device", Toast.LENGTH_LONG)
.show();
} else { // check for front camera
cameraId = findFrontFacingCamera();
if (cameraId < 0) {
Toast.makeText(this, "No front facing camera found.",
Toast.LENGTH_LONG).show();
} else {
camera = Camera.open(cameraId);
}
}// end else ,check for front camera
// if camera is not null , than display incoming images on a preview screen on SurfaceView
if (camera != null) {
//implement later
}
// create text area & scan button
VINtext = (TextView) findViewById(R.id.mytext);
scanButton = findViewById(R.id.webbutton);
scanButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
camera.takePicture(null, null, jpegCallback);
}
});
}// end onCreate
private int findFrontFacingCamera() {
int cameraId = -1;
// Search for the front facing camera
int numberOfCameras = Camera.getNumberOfCameras();
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
Log.d("ClassScanViewBarcodeActivity , findFrontFacingCamera(): ",
"Camera found");
cameraId = i;
break;
}
}
return cameraId;
}// end findFrontFacingCamera()
@Override
protected void onPause() {
if (camera != null) {
camera.release();
camera = null;
}
super.onPause();
}// end onPause()
public String decodeBitmapToString(BinaryBitmap bitmap) {
Reader reader = null;
Result result = null;
String textResult = null;
try {
reader = new MultiFormatReader();
if (bitmap != null) {
result = reader.decode(bitmap);
if (result != null) {
textResult = result.getText();
} else {
Log.d("ClassScanViewBarcodeActivity , String decodeBitmapToString (BinaryBitmap bitmap): result = ",
String.valueOf(result));
}
} else {
Log.d("ClassScanViewBarcodeActivity , String decodeBitmapToString (BinaryBitmap bitmap): bitmap = ",
String.valueOf(bitmap));
}
/*
* byte[] rawBytes = result.getRawBytes(); BarcodeFormat format =
* result.getBarcodeFormat(); ResultPoint[] points =
* result.getResultPoints();
*/
} catch (NotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ChecksumException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FormatException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return textResult;
}// end decodeBitmapToString (BinaryBitmap bitmap)
public BinaryBitmap cameraBytesToBinaryBitmap(Bitmap bitmap) {
BinaryBitmap binaryBitmap = null;
if (bitmap != null) {
int[] pixels = new int[bitmap.getHeight() * bitmap.getWidth()];
bitmap.getPixels(pixels, 0, 0, bitmap.getWidth() - 1,
bitmap.getHeight() - 1, bitmap.getWidth(),
bitmap.getHeight());
RGBLuminanceSource source = new RGBLuminanceSource(
bitmap.getWidth(), bitmap.getHeight(), pixels);
HybridBinarizer bh = new HybridBinarizer(source);
binaryBitmap = new BinaryBitmap(bh);
} else {
Log.d("ClassScanViewBarcodeActivity , cameraBytesToBinaryBitmap (Bitmap bitmap): bitmap = ",
String.valueOf(bitmap));
}
return binaryBitmap;
}
}// end activity
4）ScanVinFromBarcodeActivity活动的布局：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="20dip"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="@color/mbackground1"
android:gravity="center_horizontal"
android:text="@string/decode_label"
android:padding="20dip" />
<TextView
android:id="@+id/mytext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:background="@color/mbackground2"
android:textColor="@color/mytextcolor"
android:padding="20dip"/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/continue_label"
android:gravity="center_horizontal"
android:textColor="@color/mytextcolor"
android:padding="20dip"/>
<Button
android:id="@+id/webbutton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/web_button"
android:textColor="@color/mytextcolor"/>
</LinearLayout>
Eclipse能够解析这些类，我已经使用了其他2个“core.jar”文件，并且还编译了我自己的版本，但仍然无法在运行时找到这些类。
我甚至使用了“jar xf”命令并展开了core-2.2.jar，发现它们应该是两个类，请看下面的内容：
任何帮助将不胜感激。
谢谢
1 个答案:
答案 0 :(得分：0)
我解决了这个问题。
虽然最初通过Eclipse菜单添加了zxing API的core-2.2.jar，但是通过转到项目属性而不是Java Build Path，而不是添加外部JARS 并且核心jar出现在项目树中，由于某种原因，某些类在运行时被发现。
所以我手动复制将core-2.2.jar粘贴到项目的/ libs文件夹中，一切都在编译＆amp;运行。
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