File manager based on java.io.File.

  File manager based on java.io.File. A common way
to obtain an instance of this class is using getStandardFileManager, for example:

   JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
   DiagnosticCollector<JavaFileObject> diagnostics =
       new DiagnosticCollector<JavaFileObject>();
   StandardJavaFileManager fm = compiler.getStandardFileManager(diagnostics, null, null);
 

This file manager creates file objects representing regular
files,
zip file entries, or entries in
similar file system based containers. Any file object returned
from a file manager implementing this interface must observe the
following behavior:

• 
  File names need not be canonical.
  


• 
  For file objects representing regular files
  
  
  
  • 
    the method FileObject.delete()
    is equivalent to File.delete(),
    
  
  
  • 
    the method FileObject.getLastModified()
    is equivalent to File.lastModified(),
    
  
  
  • 
    the methods FileObject.getCharContent(boolean),
    FileObject.openInputStream(), and
    FileObject.openReader(boolean)
    must succeed if the following would succeed (ignoring
    encoding issues):
    

    
    

    new FileInputStream(new File(fileObject.toUri()))

    
    

    
    
  
  
  • 
    and the methods
    FileObject.openOutputStream(), and
    FileObject.openWriter() must
    succeed if the following would succeed (ignoring encoding
    issues):
    

    
    

    new FileOutputStream(new File(fileObject.toUri()))

    
    

    
    
  
  
  
  


• 
  The URI returned from
  FileObject.toUri()
  
  
  
  • 
    must be absolute (have a schema), and
    
  
  
  • 
    must have a normalized
    path component which
    can be resolved without any process-specific context such
    as the current directory (file names must be absolute).
    
  
  
  
  

According to these rules, the following URIs, for example, are
allowed:

• 
  file:///C:/Documents%20and%20Settings/UncleBob/BobsApp/Test.java
  


• 
  jar:///C:/Documents%20and%20Settings/UncleBob/lib/vendorA.jar!com/vendora/LibraryClass.class
  

Whereas these are not (reason in parentheses):

• 
  file:BobsApp/Test.java (the file name is relative
  and depend on the current directory)
  


• 
  jar:lib/vendorA.jar!com/vendora/LibraryClass.class
  (the first half of the path depends on the current directory,
  whereas the component after ! is legal)
  


• 
  Test.java (this URI depends on the current
  directory and does not have a schema)
  


• 
  jar:///C:/Documents%20and%20Settings/UncleBob/BobsApp/../lib/vendorA.jar!com/vendora/LibraryClass.class
  (the path is not normalized)