Preferred way of loading resources in Java

Question

I would like to know the best way of loading a resource in Java    this getClass   getResource    or getResourceAsStream     Thread currentThread   getContextClassLoader   getResource name   System class getResource name

User · Answer

I search three places as shown below  Comments welcome   public URL getResource String resource        URL url          Try with the Thread Context Loader       ClassLoader classLoader   Thread currentThread   getContextClassLoader        if classLoader    null           url   classLoader getResource resource           if url    null               return url                         Let s now try with the classloader that loaded this class      classLoader   Loader class getClassLoader        if classLoader    null           url   classLoader getResource resource           if url    null               return url                         Last ditch attempt  Get the resource from the classpath      return ClassLoader getSystemResource resource

User · Answer

I know it really late for another answer but I just wanted to share what helped me at the end  It will also load resources files from the absolute path of the file system  not only the classpath s    public class ResourceLoader        public static URL getResource String resource            final List lt ClassLoader gt  classLoaders   new ArrayList lt ClassLoader gt             classLoaders add Thread currentThread   getContextClassLoader             classLoaders add ResourceLoader class getClassLoader              for  ClassLoader classLoader   classLoaders                final URL url   getResourceWith classLoader  resource               if  url    null                    return url                                   final URL systemResource   ClassLoader getSystemResource resource           if  systemResource    null                return systemResource            else               try                   return new File resource  toURI   toURL                  catch  MalformedURLException e                    return null                                     private static URL getResourceWith ClassLoader classLoader  String resource            if  classLoader    null                return classLoader getResource resource                     return null

User · Answer

Work out the solution according to what you want     There are two things that getResource getResourceAsStream   will get from the class it is called on      The class loader The starting location   So if you do   this getClass   getResource  foo txt      it will attempt to load foo txt from the same package as the  this  class and with the class loader of the  this  class  If you put a     in front then you are absolutely referencing the resource   this getClass   getResource   x y z foo txt     will load the resource from the class loader of  this  and from the x y z package  it will need to be in the same directory as classes in that package    Thread currentThread   getContextClassLoader   getResource name    will load with the context class loader but will not resolve the name according to any package  it must be absolutely referenced   System class getResource name    Will load the resource with the system class loader  it would have to be absolutely referenced as well  as you won t be able to put anything into the java lang package  the package of System    Just take a look at the source  Also indicates that getResourceAsStream just calls  openStream  on the URL returned from getResource and returns that

User · Answer

I tried a lot of ways and functions that suggested above  but they didn t work in my project  Anyway I have found solution and here it is   try       InputStream path   this getClass   getClassLoader   getResourceAsStream  img left-hand png        img   ImageIO read path     catch  IOException e        e printStackTrace

User · Answer

Well  it partly depends what you want to happen if you re actually in a derived class   For example  suppose SuperClass is in A jar and SubClass is in B jar  and you re executing code in an instance method declared in SuperClass but where this refers to an instance of SubClass  If you use this getClass   getResource   it will look relative to SubClass  in B jar  I suspect that s usually not what s required   Personally I d probably use Foo class getResourceAsStream name  most often - if you already know the name of the resource you re after  and you re sure of where it is relative to Foo  that s the most robust way of doing it IMO   Of course there are times when that s not what you want  too  judge each case on its merits  It s just the  I know this resource is bundled with this class  is the most common one I ve run into

[java] Preferred way of loading resources in Java

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