I am trying to retrieve all DocumentFile[] using listFiles() method.But getting a null pointer exception how to eliminate this error and still get the files.
This is the code which searches sd card root directory which is being passed as documentfile in method parameter.
private List<DocumentFile> getListFiles2(DocumentFile docfile) {
List<DocumentFile> inFiles = new ArrayList<>();
Queue<DocumentFile> files = new LinkedList<>();
// check error arising here
files.addAll(Arrays.asList(docfile.listFiles()));
while (!files.isEmpty()) {
DocumentFile file = files.remove();
if (file.isDirectory()) {
files.addAll(Arrays.asList(file.listFiles()));
} else if (file.getName().endsWith(".bmp")
|| file.getName().endsWith(".gif")
|| file.getName().endsWith(".jpg") || file.getName().endsWith(".jpeg")
|| file.getName().endsWith(".png")
) {
inFiles.add(file);
}
}
return inFiles;
}
Related
I'm making a .net Core WebApi using .Net Core 2.2. The API is ready but the failure message and response is where I'm stuck at.
Right now, I'm getting respose like below
json
{
"empId":1999,
"empName":"Conroy, Deborah",
"enrollmentStatus":true,
"primaryFingerprintScore":65,
"secondaryFingerprintScore":60,
"primaryFingerprint":null,
"secondaryFingerprint":null,
"primaryFingerprintType":null,
"secondaryFingerprintType":null}
}
I created a json formatter class and wrote the below code
public class SuperJsonOutputFormatter : JsonOutputFormatter
{
public SuperJsonOutputFormatter(
JsonSerializerSettings serializerSettings,
ArrayPool<char> charPool) : base(serializerSettings, charPool)
{
}
public override async Task WriteResponseBodyAsync(
OutputFormatterWriteContext context,
Encoding selectedEncoding)
{
if (context == null)
throw new ArgumentNullException(nameof(context));
if (selectedEncoding == null)
throw new ArgumentNullException(nameof(selectedEncoding));
using (TextWriter writer =
context.WriterFactory(
context.HttpContext.Response.Body,
selectedEncoding))
{
var rewrittenValue = new
{
resultCode = context.HttpContext.Response.StatusCode,
resultMessage =
((HttpStatusCode)context.HttpContext.Response.StatusCode)
.ToString(),
result = context.Object
};
this.WriteObject(writer, rewrittenValue);
await writer.FlushAsync();
}
}
I expect all the error codes to be sent as generic error messages like the JSON below.
FOR STATUS OKAY:
{
"status" : True,
"error" : null,
"data" : {
{
"empId":1999,
"empName":"Conroy, Deborah",
"enrollmentStatus":true,
"primaryFingerprintScore":65,
"secondaryFingerprintScore":60,
"primaryFingerprint":null,
"secondaryFingerprint":null,
"primaryFingerprintType":null,
"secondaryFingerprintType":null}
}
}
}
FOR OTHER STATUS LIKE 404, 500, 400, 204
{
"status" : False,
"error" : {
"error code" : 404,
"error description" : Not Found
},
"data" : null
}
I expect all the error codes to be sent as generic error messages like the JSON below
You're almost there. What you need to do is enabling your SuperJsonOutputFormatter.
A Little Change to Your Formatter
Firstly, your formatter didn't return a json with the same schema as you want. So I create a dummy class to hold the information for error code and error description:
public class ErrorDescription{
public ErrorDescription(HttpStatusCode statusCode)
{
this.Code = (int)statusCode;
this.Description = statusCode.ToString();
}
[JsonProperty("error code")]
public int Code {get;set;}
[JsonProperty("error description")]
public string Description {get;set;}
}
And change your WriteResponseBodyAsync() method as below:
...
using (TextWriter writer = context.WriterFactory(context.HttpContext.Response.Body, selectedEncoding)) {
var statusCode = context.HttpContext.Response.StatusCode;
var rewrittenValue = new {
status = IsSucceeded(statusCode),
error = IsSucceeded(statusCode) ? null : new ErrorDescription((HttpStatusCode)statusCode),
data = context.Object,
};
this.WriteObject(writer, rewrittenValue);
await writer.FlushAsync();
}
Here the IsSucceeded(statusCode) is a simple helper method that you can custom as you need:
private bool IsSucceeded(int statusCode){
// I don't think 204 indicates that's an error.
// However, you could comment out it if you like
if(statusCode >= 400 /* || statusCode==204 */ ) { return false; }
return true;
}
Enable your Formatter
Secondly, to enable your custom Formatter, you have two approaches: One way is to register it as an global Formatter, the other way is to enable it for particular Controller or Action. Personally, I believe the 2nd way is better. So I create a Action Filter to enable your formatter.
Here's an implementation of the Filter that enables your custom formatter dynamically:
public class SuperJsonOutputFormatterFilter : IAsyncActionFilter{
private readonly SuperJsonOutputFormatter _formatter;
// inject your SuperJsonOutputFormatter service
public SuperJsonOutputFormatterFilter(SuperJsonOutputFormatter formatter){
this._formatter = formatter;
}
// a helper method that provides an ObjectResult wrapper over the raw object
private ObjectResult WrapObjectResult(ActionExecutedContext context, object obj){
var wrapper = new ObjectResult(obj);
wrapper.Formatters.Add(this._formatter);
context.Result= wrapper;
return wrapper;
}
public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
{
ActionExecutedContext resultContext = await next();
// in case we get a 500
if(resultContext.Exception != null && ! resultContext.ExceptionHandled){
var ewrapper = this.WrapObjectResult(resultContext, new {});
ewrapper.StatusCode = (int) HttpStatusCode.InternalServerError;
resultContext.ExceptionHandled = true;
return;
}
else {
switch(resultContext.Result){
case BadRequestObjectResult b : // 400 with an object
var bwrapper=this.WrapObjectResult(resultContext,b.Value);
bwrapper.StatusCode = b.StatusCode;
break;
case NotFoundObjectResult n : // 404 with an object
var nwrapper=this.WrapObjectResult(resultContext,n.Value);
nwrapper.StatusCode = n.StatusCode;
break;
case ObjectResult o : // plain object
this.WrapObjectResult(resultContext,o.Value);
break;
case JsonResult j : // plain json
this.WrapObjectResult(resultContext,j.Value);
break;
case StatusCodeResult s: // other statusCodeResult(including NotFound,NoContent,...), you might want to custom this case
var swrapper = this.WrapObjectResult(resultContext, new {});
swrapper.StatusCode = s.StatusCode;
break;
}
}
}
}
And don't forget to register your formatter as a service :
services.AddScoped<SuperJsonOutputFormatter>();
Finally, when you want to enable your formatter, just add a [TypeFilter(typeof(SuperJsonOutputFormatterFilter))] annotation for the controller or action.
Demo
Let's create an action method for Test:
[TypeFilter(typeof(SuperJsonOutputFormatterFilter))]
public IActionResult Test(int status)
{
// test json result(200)
if(status == 200){ return Json(new { Id = 1, }); }
// test 400 object result
else if(status == 400){ return BadRequest( new {}); }
// test 404 object result
else if(status == 404){ return NotFound(new { Id = 1, }); }
// test exception
else if(status == 500){ throw new Exception("unexpected exception"); }
// test status code result
else if(status == 204){ return new StatusCodeResult(204); }
// test normal object result(200)
var raw = new ObjectResult(new XModel{
empId=1999,
empName = "Conroy, Deborah",
enrollmentStatus=true,
primaryFingerprintScore=65,
secondaryFingerprintScore=60,
primaryFingerprint = null,
secondaryFingerprint= null,
primaryFingerprintType=null,
secondaryFingerprintType=null
});
return raw;
}
Screenshot:
I need to create a folder when it doesn't exist. In my case, the only way to do so is to capture the error and handle it to create the folder wanted.
But all i can find is
public static Observable<Boolean> folderExists(final Context context, final String targetPath, final String currentpath) {
Application application = Application.get(context);
//i browse the folder to get all the items
return browseFolderObservable(context,currentpath)
.subscribeOn(application.defaultSubscribeScheduler())
.doOnError(new Action1<Throwable>() {
#Override
public void call(Throwable throwable) {
BsSdkLog.d("Error no file found");
}
})
.map(new Func1<ArrayList<Item>, Boolean>() {
#Override
public Boolean call(ArrayList<Item> items) {
if(items.isEmpty()) {
BsSdkLog.d(" No items");
return false;
}else {
for(int i=0;i<items.size();i++)
{
Item item=items.get(i);
BsSdkLog.d(item.toString());
}
BsSdkLog.d("Right-here");
return true;
}
}
});
}
I want to call the method that i have that creates the folder when the error occurs but i don't know how to do that.
I'm new to this so i'd really appreciate the help
Thanks
The basic principe looks like this. I used the Java NIO library for testing.
The method 'createFolder' just wraps creating a folder. The test 'name' invokes the Single and checks for an Exception. If it is an IOException it will return a fallback value. You may do something different in there. You just provide a fallback single. If it is an error different from IOException, it will return the error.
#Test
void name() throws Exception {
final String TO_CREATE = "/home/sergej/Downloads/Wurstbrot";
this.createFolder(TO_CREATE)
.onErrorResumeNext(throwable -> { // handle Exception:
// Validate Exception
if (throwable instanceof IOException) {
// Return fallback
return Single.just(Paths.get("/home/sergej/Downloads/"));
}
return Single.error(throwable);
})
.test()
.await()
.assertValueCount(1)
.assertValue(path -> path.endsWith(TO_CREATE))
.assertNoErrors();
}
private Single<Path> createFolder(String p) {
return Single.defer(() -> { // may throw some IOException
Path path = Paths.get(p);
if (!Files.exists(path)) {
Path createdDirectory = Files.createDirectory(path); // will throw if already exists
return Single.just(createdDirectory);
}
// Or just return Path, because it already exists???
return Single.error(new IOException("Already exists"));
});
}
I am working on a multilingual ASP.NET MVC application (MVC4).
I want to make my resource file strings to be editable at runtime without recompiling the application and without app pool recycling And it doesn't look possible with .resx file, so I migrate to store string resources in Database.
I have to Get Each Label/String Resource From Database, so there will be more hits to database for each request. How to fix that?
I have googled around and someone suggests to load the resource in a dictionary and store it as application variable, at login/Sign In page and use that dictionary as resource instead of database hit.
I am confused, what will be effective approach.Can someone guide me in right direction to avoid more database hits?
Any help/suggestions will be highly appreciated.
Thanks
I ran into the same concerns using .resx files for localization. They just did not work well when the persons doing the translation were not programmers. Now, we have a translation page in our admin area. Works great.
One area which we still don't have a good solution for are the data annotations, which still use the .resx files. I have trimmed the source below to remove any references to our actual database structures or tables.
There is a fallback to using the underlying .resx file, if an entry does not exist in the database. If there is not an entry in the .resx file, I split the word whenever a capitol letter is found ( CamelSpace is a string extension method ).
Lastly, depending on your implementation, you may need to remove the context caching, especially if you are caching out of process.
A few examples of usage:
#LanguageDb.Translate("Enter your first name below","FirstNamePrompt")
#LanguageDb.Me.FirstName
#String
.Format(LanguageDb
.Translate(#"You can be insured for
{0} down and {1} payments of {2}"),
Model.Down,Model.NumPayments,
Model.InstallmentAmount)
public class LanguageDb : DynamicObject
{
public static dynamic Me = new LanguageDb();
private LanguageDb() { }
public static string Translate(string englishPhrase, string resourceCode = null)
{
return GetTranslation(englishPhrase, resourceCode) ?? englishPhrase;
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
result = GetTranslation(binder.Name);
return true;
}
private static string GetTranslation(string resourceName, string resourceCode = null)
{
resourceCode = resourceCode ?? resourceName;
if (resourceCode.Contains(" ") || resourceCode.Length > 50)
{
resourceCode = resourceName.GetHashCode().ToString(CultureInfo.InvariantCulture);
}
var lang = (string)HttpContext.Current.Request.RequestContext.RouteData.Values["lang"] ?? "en";
// cache entries for an hour
var result = Get(subagent + "_" + lang + "_" + resourceCode, 3600, () =>
{
// cache a datacontext object for 30 seconds.
var context = Get("_context", 30, () => new YourDataContext()) as YourDataContext;
var translation = context.Translations.FirstOrDefault(row => row.lang == lang && row.Code == resourceCode);
if (translation == null)
{
translation = new Lookup {
Code = resourceCode,
lang = lang,
Value = Language.ResourceManager.GetString(resourceName, Language.Culture)
?? resourceName.CamelSpace()
};
context.Translations.Add(translation);
context.SaveChanges();
}
return translation.Value;
});
return result;
}
public override bool TrySetMember(SetMemberBinder binder, object value)
{
// ignore this
return true;
}
public static T Get<T>(string cacheId, int secondsToCache, Func<T> getItemCallback) where T : class
{
T item = HttpRuntime.Cache.Get(cacheId) as T;
if (item == null)
{
item = getItemCallback();
if (secondsToCache > 0)
{
HttpRuntime.Cache.Insert(
cacheId, item, null, Cache.NoAbsoluteExpiration,
new TimeSpan(0, 0, secondsToCache), CacheItemPriority.Normal, null);
}
else
{
HttpRuntime.Cache.Insert(cacheId, item);
}
}
return item;
}
}
I am using the following script to select an object from a set of input objects using an index.
It does not recognize that the input argument is a set of three values.
I assume I am doing something wrong in the line:
if(setOfObjects instanceof java.util.Collection)
if(setOfObjects != null)
{
if(setOfObjects instanceof java.util.Collection)
{
object = setOfObjects.get(index);
if (object instanceof fUML.Semantics.Classes.Kernel.Object_)
{
fUML.Semantics.Classes.Kernel.Reference r = new fUML.Semantics.Classes.Kernel.Reference(object.getOwner());
r.setReferent(object);
object = r;
}
}
Else print(index);
if(index == 1)
{
print("ok");
object = setOfObjects;
}
else
{
print("failed");
object = null;
}
}
else
{
object = null;
}
GaryMcM's approach is correct. The code worked correctly for me when I set setOfObjects as instance of java.util.HashSet in interpreter namespace, as below.
Set<String> setOfObjects = new HashSet<String>();
i.set("setOfObjects", setOfObjects );(i being beanshell interpreter's instance)
few observations :
keyword Else should be else (beanshell doesn't tolerate it)
setOfObjects.get(index); will throw error as there is no get(int) in Sets
Are you sure the setOfObjects which you are providing is not null, or with no typo error, as beanshell will assume a variable with typo error as new one. (in non strict java mode).
I am trying to utilize SharePoint 2010 Client Object Model to create a List based on a custom template. Here's my code:
public void MakeList(string title, string listTemplateGUID, int localeIdentifier)
{
string message;
string listUrl;
ListTemplate template;
ListCreationInformation listInfo;
ListTemplateCollection templatesCollection;
try
{
listUrl = title.Replace(spaceChar, string.Empty);
templatesCollection = clientContext.Site.GetCustomListTemplates(clientContext.Web);
clientContext.Load(templatesCollection);
clientContext.ExecuteQuery();
foreach (ListTemplate t in templatesCollection)
{
if (t.InternalName == listTemplate)
{
template = t;
break;
}
}
listInfo = new ListCreationInformation();
listInfo.TemplateType = template.ListTemplateTypeKind;
//listInfo.TemplateFeatureId = template.FeatureId;
listInfo.Url = listUrl;
listInfo.Title = title;
listInfo.Description = string.Empty;
listInfo.QuickLaunchOption = QuickLaunchOptions.On;
site.Lists.Add(listInfo);
clientContext.ExecuteQuery();
return RetrieveList(title, listUrl);
}
catch (ServerException ex)
{
//...
}
}
A few unexpected things happen when this code is run:
My template is derived from the default document library template. Now, the code above does not create the document library based on my template - it creates the default document library instead.
If I uncomment the //listInfo.TemplateFeatureId = template.FeatureId; the code throws the ServerException error: "Cannot complete this action. Please try again."
If I place listInfo.TemplateFeatureId = template.FeatureId; before listInfo.TemplateType = template.ListTemplateTypeKind; the end result is the same as under item 1 - the default document library is created.
Could anyone please help me realize what am I doing wrong? Thanks.