[英]downloading and saving image into sd card
我正在尝试将图像下载并保存到SD卡中,有时它可以工作,有时却不能。 我需要帮助以了解原因,并且尝试使用Google,但找不到答案。
所以这是我的代码,用于检索杂志问题,然后循环遍历json数组中的每个项目,然后将其下载并存储到sd卡中。 但是某些图像没有下载,而是跳过(查看logcat)
/**
* Background Async Task to Load all product by making HTTP Request
* */
class downloadMagazine extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog = new ProgressDialog(Store.this);
progressDialog.setMessage("Loading.." + "\n" + "加载中..");
progressDialog.setIndeterminate(false);
progressDialog.setCancelable(false);
progressDialog.show();
}
/**
* getting preview url and then load them
* */
protected String doInBackground(String... args) {
URL myFileUrl = null;
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_magazine, "GET", params);
// Check your log cat for JSON reponse
//Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
mag = json.getJSONArray(TAG_MAGAZINE);
for (int i = 0; i < mag.length(); i++) {
JSONObject c = mag.getJSONObject(i);
// Storing each json item in variable
String magazineUrl = c.getString(TAG_MAGAZINE_URL);
String issueName = c.getString(TAG_MAGAZINE_NAME);
urlList.add(magazineUrl);
issueNameList.add(issueName);
//System.out.println(urlList);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
// Building Parameters
List<NameValuePair> param = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json1 = jParser.makeHttpRequest(urlList.get(pos), "GET", param);
// CHECKING OF JSON RESPONSE
Log.d("All guide: ", json.toString());
try {
issues = json1.getJSONArray(TAG_ISSUE);
for (int i = 0; i < issues.length(); i++) {
JSONObject c = issues.getJSONObject(i);
String image = c.getString(TAG_IMAGE);
imageList.add(image);
//System.out.println(imageList);
}
// STOP THE LOOP
//break;
} catch (JSONException e) {
e.printStackTrace();
}
for (int i = 0; i < imageList.size(); i ++)
{
imageUrl = imageList.get(i).toString();
Log.d("thumbnail", imageUrl);
number = i;
try {
myFileUrl = new URL(imageUrl); // RETRIEVE IMAGE URL
}
catch (MalformedURLException e) {
e.printStackTrace();
}
try {
HttpURLConnection conn = (HttpURLConnection) myFileUrl.openConnection();
conn.setDoInput(true);
conn.connect();
InputStream in = conn.getInputStream();
Log.i("I'm connected", "Download");
bmImg = BitmapFactory.decodeStream(in);
File filename;
// GET EXTERNAL STORAGE, SAVE FILE THERE
File storagePath = new File(Environment.getExternalStorageDirectory(),folderName+"issue"+issueNumber+"/");
storagePath.mkdirs();
filename = new File(storagePath + "/page"+number+".jpg");
FileOutputStream out = new FileOutputStream(filename);
bmImg.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
MediaStore.Images.Media.insertImage(getContentResolver(),filename.getAbsolutePath(), filename.getName(),
filename.getName());
in.close();
// displayImage();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
每当它跳过下载页面时,这就是我的logcat输出(我知道它与我发布的问题之一相似,但我确实需要在排除故障方面提供帮助)。 我不知道发生了什么,我在Google上搜索了一下,发现许多使用android 4.0以后的版本都遇到了这个问题
01-23 17:09:29.120: W/System.err(24339): java.io.EOFException
01-23 17:09:29.120: W/System.err(24339): at libcore.io.Streams.readAsciiLine(Streams.java:203)
01-23 17:09:29.120: W/System.err(24339): at libcore.net.http.HttpEngine.readResponseHeaders(HttpEngine.java:544)
01-23 17:09:29.120: W/System.err(24339): at libcore.net.http.HttpEngine.readResponse(HttpEngine.java:784)
01-23 17:09:29.120: W/System.err(24339): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:274)
01-23 17:09:29.120: W/System.err(24339): at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
01-23 17:09:29.130: W/System.err(24339): at libcore.net.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:270)
01-23 17:09:29.130: W/System.err(24339): at com.sfcca.coverflow.Store$downloadMagazine.doInBackground(Store.java:881)
01-23 17:09:29.130: W/System.err(24339): at com.sfcca.coverflow.Store$downloadMagazine.doInBackground(Store.java:1)
01-23 17:09:29.130: W/System.err(24339): at android.os.AsyncTask$2.call(AsyncTask.java:264)
01-23 17:09:29.130: W/System.err(24339): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
01-23 17:09:29.130: W/System.err(24339): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
01-23 17:09:29.130: W/System.err(24339): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
01-23 17:09:29.130: W/System.err(24339): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
01-23 17:09:29.130: W/System.err(24339): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
01-23 17:09:29.130: W/System.err(24339): at java.lang.Thread.run(Thread.java:856)
检查您是否已对清单指定了适当的权限
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
看看这个: http : //code.google.com/p/google-http-java-client/issues/detail?id=116
我会在那儿尝试最后的评论,看看问题是否消失了:
System.setProperty(“ http.keepAlive”,“ false”);
现在,您可能不一定要长期使用该设置,但至少要看看是否相关。
并且请注意,即使这个问题涉及Spring和其他许多东西,也似乎是相同的根本问题: Spring Rest Template的使用会导致EOFException
最后,我不确定您要在其中做什么,但是使用一个AsyncTask要做很多工作(并不能真正处理诸如网络中断之类的突发事件,等等),但是您可能会遇到其他几种麻烦在那里(与您的问题无关)。 如果可能有用,您可能还想考虑使用通用图像下载/缓存库,例如https://github.com/koush/UrlImageViewHelper 。 即使您不使用其中之一,也可以仔细研究一下源代码,您可能会发现它们如何使事情变得更强大。
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