需要在android应用程序上识别此异常的帮助吗
使用我的android应用程序时，我从另一个活动打开一个活动时会出现此异常。我需要您的帮助，以确定我的代码中应该从何处开始解决此问题：需要在android应用程序上识别此异常的帮助吗,android,Android,使用我的android应用程序时，我从另一个活动打开一个活动时会出现此异常。我需要您的帮助，以确定我的代码中应该从何处开始解决此问题： 04-16 19:55:43.014: I/MemoryCache(1083): MemoryCache will use up to 4.0MB 04-16 19:55:43.044: D/AndroidRuntime(1083): Shutting down VM 04-16 19:55:43.054: W/dalvikvm(1083): threadid=
04-16 19:55:43.014: I/MemoryCache(1083): MemoryCache will use up to 4.0MB
04-16 19:55:43.044: D/AndroidRuntime(1083): Shutting down VM
04-16 19:55:43.054: W/dalvikvm(1083): threadid=1: thread exiting with uncaught exception (group=0xb4a53ba8)
04-16 19:55:43.124: E/AndroidRuntime(1083): FATAL EXCEPTION: main
04-16 19:55:43.124: E/AndroidRuntime(1083): Process: com.solinpromex.vivegrancanaria, PID: 1083
04-16 19:55:43.124: E/AndroidRuntime(1083): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.solinpromex.vivegrancanaria/com.solinpromex.vivegrancanaria.Empresas_SingleItemView}: java.lang.NullPointerException
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2121)
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.os.Handler.dispatchMessage(Handler.java:102)
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.os.Looper.loop(Looper.java:136)
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-16 19:55:43.124: E/AndroidRuntime(1083): at java.lang.reflect.Method.invokeNative(Native Method)
04-16 19:55:43.124: E/AndroidRuntime(1083): at java.lang.reflect.Method.invoke(Method.java:515)
04-16 19:55:43.124: E/AndroidRuntime(1083): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-16 19:55:43.124: E/AndroidRuntime(1083): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-16 19:55:43.124: E/AndroidRuntime(1083): at dalvik.system.NativeStart.main(Native Method)
04-16 19:55:43.124: E/AndroidRuntime(1083): Caused by: java.lang.NullPointerException
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.content.ContextWrapper.getCacheDir(ContextWrapper.java:230)
04-16 19:55:43.124: E/AndroidRuntime(1083): at com.solinpromex.vivegrancanaria.FileCache.<init>(FileCache.java:17)
04-16 19:55:43.124: E/AndroidRuntime(1083): at com.solinpromex.vivegrancanaria.ImageLoader.<init>(ImageLoader.java:34)
04-16 19:55:43.124: E/AndroidRuntime(1083): at com.solinpromex.vivegrancanaria.Empresas_SingleItemView.<init>(Empresas_SingleItemView.java:16)
04-16 19:55:43.124: E/AndroidRuntime(1083): at java.lang.Class.newInstanceImpl(Native Method)
04-16 19:55:43.124: E/AndroidRuntime(1083): at java.lang.Class.newInstance(Class.java:1208)
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
04-16 19:55:43.124: E/AndroidRuntime(1083): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2112)
04-16 19:55:43.124: E/AndroidRuntime(1083): ... 11 more
import java.io.File;
import android.content.Context;
public class FileCache {
private File cacheDir;
public FileCache(Context context) {
// Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED))
cacheDir = new File(
android.os.Environment.getExternalStorageDirectory(),
"JsonParseTutorialCache");
else
cacheDir = context.getCacheDir();
if (!cacheDir.exists())
cacheDir.mkdirs();
}
public File getFile(String url) {
String filename = String.valueOf(url.hashCode());
// String filename = URLEncoder.encode(url);
File f = new File(cacheDir, filename);
return f;
}
public void clear() {
File[] files = cacheDir.listFiles();
if (files == null)
return;
for (File f : files)
f.delete();
}
}
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.os.Handler;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
// Handler to display images in UI thread
Handler handler = new Handler();
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.temp_img;
public void DisplayImage(String url, ImageView imageView) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else {
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView) {
PhotoToLoad p = new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
Bitmap b = decodeFile(f);
if (b != null)
return b;
// Download Images from the Internet
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
conn.disconnect();
bitmap = decodeFile(f);
return bitmap;
} catch (Throwable ex) {
ex.printStackTrace();
if (ex instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// Decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f) {
try {
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream stream1 = new FileInputStream(f);
BitmapFactory.decodeStream(stream1, null, o);
stream1.close();
// Find the correct scale value. It should be the power of 2.
// Recommended Size 512
final int REQUIRED_SIZE = 70;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
FileInputStream stream2 = new FileInputStream(f);
Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
} catch (FileNotFoundException e) {
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad) {
this.photoToLoad = photoToLoad;
}
@Override
public void run() {
try {
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
handler.post(bd);
} catch (Throwable th) {
th.printStackTrace();
}
}
}
boolean imageViewReused(PhotoToLoad photoToLoad) {
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
bitmap = b;
photoToLoad = p;
}
public void run() {
if (imageViewReused(photoToLoad))
return;
if (bitmap != null)
photoToLoad.imageView.setImageBitmap(bitmap);
else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}
导入java.io.File；
导入java.io.FileInputStream；
导入java.io.FileNotFoundException；
导入java.io.FileOutputStream；
导入java.io.IOException；
导入java.io.InputStream；
导入java.io.OutputStream；
导入java.net.HttpURLConnection；
导入java.net.URL；
导入java.util.Collections；
导入java.util.Map；
导入java.util.WeakHashMap；
导入java.util.concurrent.ExecutorService；
导入java.util.concurrent.Executors；
导入android.os.Handler；
导入android.content.Context；
导入android.graphics.Bitmap；
导入android.graphics.BitmapFactory；
导入android.widget.ImageView；
公共类图像加载器{
MemoryCache MemoryCache=新的MemoryCache（）；
文件缓存文件缓存；
私有地图图像视图=集合
.synchronizedMap（新WeakHashMap（））；
执行服务执行服务；
//在UI线程中显示图像的处理程序
Handler=newhandler（）；
公共图像加载器（上下文）{
fileCache=新的fileCache（上下文）；
executorService=Executors.newFixedThreadPool（5）；
}
最终整数存根id=R.drawable.temp\u img；
public void DisplayImage（字符串url，ImageView）{
put（imageView，url）；
位图位图=memoryCache.get（url）；
if（位图！=null）
设置图像位图（位图）；
否则{
队列照片（url、imageView）；
setImageResource（存根id）；
}
}
私有void队列照片（字符串url，ImageView）{
PhotoToLoad p=新的PhotoToLoad（url，imageView）；
executorService.submit（新的PhotoLoader（p））；
}
私有位图getBitmap（字符串url）{
文件f=fileCache.getFile（url）；
位图b=解码文件（f）；
如果（b！=null）
返回b；
//从Internet下载图像
试一试{
位图=空；
URL imageUrl=新URL（URL）；
HttpURLConnection conn=（HttpURLConnection）imageUrl
.openConnection（）；
连接设置连接超时（30000）；
连接设置读取超时（30000）；
conn.setInstanceFollowRedirects（真）；
InputStream is=conn.getInputStream（）；
OutputStream os=新文件OutputStream（f）；
Utils.CopyStream（is，os）；
os.close（）；
连接断开（）；
位图=解码文件（f）；
返回位图；
}捕获（可丢弃的ex）{
例如printStackTrace（）；
if（ex instanceof OutOfMemoryError）
memoryCache.clear（）；
返回null；
}
}
//对图像进行解码和缩放以减少内存消耗
私有位图解码文件（文件f）{
试一试{
//解码图像大小
BitmapFactory.Options o=新的BitmapFactory.Options（）；
o、 inJustDecodeBounds=true；
FileInputStream stream1=新的FileInputStream（f）；
解码流（stream1，null，o）；
stream1.close（）；
//找到正确的刻度值。它应该是2的幂。
//推荐尺寸512
所需的最终int_尺寸=70；
内部宽度=o.向外宽度，高度=o.向外高度；
int标度=1；
while（true）{
如果（宽度\u tmp/2<要求的\u尺寸
||高度（tmp/2<所需尺寸）
打破
宽度_tmp/=2；
高度_tmp/=2；
比例*=2；
}
//用inSampleSize解码
BitmapFactory.Options o2=新的BitmapFactory.Options（）；
o2.inSampleSize=刻度；
FileInputStream stream2=新的FileInputStream（f）；
位图位图=BitmapFactory.decodeStream（stream2，null，o2）；
stream2.close（）；
返回位图；
}catch（filenotfounde异常）{
}捕获（IOE异常）{
e、 printStackTrace（）；
}
返回null；
}
//队列的任务
私有类光电负载{
公共字符串url；
公共影像视图；
公共PhotoToLoad（字符串u，图像视图i）{
url=u；
imageView=i；
}
}
类photoloader实现可运行{
光电负载光电负载；
PhotoLoader（PhotoToLoad PhotoToLoad）{
this.photoToLoad=photoToLoad；
}
@凌驾
公开募捐{
试一试{
if（图像视图重用（光电加载））
返回；
位图bmp=getBitmap（photoLoad.url）；
memoryCache.put（photoload.url，bmp）；
if（图像视图重用（光电加载））
返回；
BitmapDisplayer bd=新的BitmapDisplayer（bmp，photoToLoad）；
邮政署署长(屋宇署)；
}捕获（可丢弃）{
th.printStackTrace（）；
}
}
}
布尔图像视图（PhotoToLoad PhotoToLoad）{
String tag=imageViews.get（photoload.imageView）；
if（tag==null | |！tag.equals（photoload.url））
返回true；
返回false；
}
//用于在UI线程中显示位图
类BitmapDisplayer实现可运行{
位图；
光电负载光电负载；
公共位图显示器（位图b、PhotoToLoad p）{
位图=b；
光电负载=p；
}
公开募捐{
if（图像视图重用（光电加载））
返回；
if（位图！=null）
photoToLoad.imageView.setImageBitmap（位图）；
其他的
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.os.Handler;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
// Handler to display images in UI thread
Handler handler = new Handler();
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.temp_img;
public void DisplayImage(String url, ImageView imageView) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else {
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView) {
PhotoToLoad p = new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
Bitmap b = decodeFile(f);
if (b != null)
return b;
// Download Images from the Internet
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
conn.disconnect();
bitmap = decodeFile(f);
return bitmap;
} catch (Throwable ex) {
ex.printStackTrace();
if (ex instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// Decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f) {
try {
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream stream1 = new FileInputStream(f);
BitmapFactory.decodeStream(stream1, null, o);
stream1.close();
// Find the correct scale value. It should be the power of 2.
// Recommended Size 512
final int REQUIRED_SIZE = 70;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
FileInputStream stream2 = new FileInputStream(f);
Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
} catch (FileNotFoundException e) {
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad) {
this.photoToLoad = photoToLoad;
}
@Override
public void run() {
try {
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
handler.post(bd);
} catch (Throwable th) {
th.printStackTrace();
}
}
}
boolean imageViewReused(PhotoToLoad photoToLoad) {
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
bitmap = b;
photoToLoad = p;
}
public void run() {
if (imageViewReused(photoToLoad))
return;
if (bitmap != null)
photoToLoad.imageView.setImageBitmap(bitmap);
else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}
// Locate the TextViews in singleitemview.xml
TextView txtvaloracionempresa = (TextView) findViewById(R.id.valoracionEmpresa);
TextView txtnombreempresa = (TextView) findViewById(R.id.nombreEmpresa);
TextView txtdireccionempresa = (TextView) findViewById(R.id.direccionEmpresa);
// Locate the ImageView in singleitemview.xml
ImageView imagenEmpresa = (ImageView) findViewById(R.id.strImagen);