Package org.simpleframework.http.parse

Class PathParser

java.lang.Object
org.simpleframework.common.parse.Parser
org.simpleframework.http.parse.PathParser
All Implemented Interfaces:
Path
public class PathParser extends Parser implements Path
This is used to parse a path given as part of a URI. This will read the path, normalize it, and break it up into its components. The normalization of the path is the conversion of the path given into it's actual path by removing the references to the parent directories and to the current dir.

If the path that this represents is /usr/bin/../etc/./README then the actual path, normalized, is /usr/etc/README. Once the path has been normalized it is possible to acquire the segments as an array of strings, which allows simple manipulation of the path.

Although RFC 2396 defines the path within a URI to have parameters this does not extract those parameters this will simply normalize the path and include the path parameters in the path. If the path is to be converted into a OS specific file system path that has the parameters extracted then the AddressParser should be used.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    private class 
    PathParser.Token
    This is used so that the PathParser can speed up the parsing of the data.
    private class 
    PathParser.TokenList
    The TokenList class is used to store a list of tokens.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private PathParser.Token
    dir
    Used to store the highest directory path.
    private PathParser.Token
    ext
    Used to store consumed file extension.
    private PathParser.TokenList
    list
    Used to store the individual path segments.
    private PathParser.Token
    name
    Used to store consumed name characters.
    private PathParser.Token
    path
    Used to store consumed normalized path name.

    Fields inherited from class org.simpleframework.common.parse.Parser

    buf, count, off

  • Constructor Summary

    Constructors
    Constructor
    Description
    PathParser()
    The default constructor will create a PathParser that contains no specifics.
    PathParser(String path)
    This is primarily a convineance constructor.

  • Method Summary

    Modifier and Type
    Method
    Description
    private void
    extension()
    This will simply read the characters from the end of the buffer until it encounters the first peroid character.
    String
    getDirectory()
    This will return the highest directory that exists within the path.
    String
    getExtension()
    This will return the extension that the file name contains.
    String
    getName()
    This will return the full name of the file without the path.
    String
    getPath()
    This will return the normalized path.
    String
    getPath(int from)
    This will return the normalized path from the specified path segment.
    String
    getPath(int from, int count)
    This will return the normalized path from the specified path segment.
    private String
    getRelative(char[] text, int off, int len)
    This will return the path as it is relative to the issued path.
    String
    getRelative(String path)
    This will return the path as it is relative to the issued path.
    private String
    getRelative(PathParser path)
    This is used by the getRelative(String) to normalize the path string and determine if it contains a highest directory which is shared with the path that is represented by this object.
    String[]
    getSegments()
    This method is used to break the path into individual parts called segments, see RFC 2396.
    protected void
    init()
    This will initialize the parser so that it is in a ready state.
    private void
    name()
    This will extract the full name of the file without the path.
    private void
    normalize()
    The normalization of the path is the conversion of the path given into it's actual path by removing the references to the parent directorys and to the current dir.
    protected void
    parse()
    This will parse the path in such a way that it ensures that at no stage there are trailing back references, using path normalization.
    private void
    path()
    This will extract the path of the given String after it has been normalized.
    private void
    segments()
    This wil extract each individual segment from the path and also extract the highest directory.
    String
    toString()
    This will return the normalized path.

    Methods inherited from class org.simpleframework.common.parse.Parser

    digit, ensureCapacity, parse, skip, space, toLower

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

  • Constructor Details

    • PathParser

      public PathParser()
      The default constructor will create a PathParser that contains no specifics. The instance will return null for all the get methods. The PathParser's get methods may be populated by using the parse method.

    • PathParser

      public PathParser(String path)
      This is primarily a convineance constructor. This will parse the String given to extract the specifics. This could be achived by calling the default no-arg constructor and then using the instance to invoke the parse method on that String to extract the parts.
      Parameters:
      path - a String containing a path value

  • Method Details

    • parse

      protected void parse()
      This will parse the path in such a way that it ensures that at no stage there are trailing back references, using path normalization. The need to remove the back references is so that this PathParser will create the same String path given a set of paths that have different back references. For example the paths /path/../path and /path are the same path but different String's.

      This will NOT parse an immediate back reference as this signifies a path that cannot exist. So a path such as /../ will result in a null for all methods. Paths such as ../bin will not be allowed.

      Specified by:
      parse in class Parser

    • init

      protected void init()
      This will initialize the parser so that it is in a ready state. This allows the parser to be used to parse many paths. This will clear the parse buffer objects and reset the offset to point to the start of the char buffer. The count variable is reset by the Parser.parse method.
      Specified by:
      init in class Parser

    • getExtension

      public String getExtension()
      This will return the extension that the file name contains. For example a file name file.en_US.extension will produce an extension of extension. This will return null if the path contains no file extension.
      Specified by:
      getExtension in interface Path
      Returns:
      this will return the extension this path contains

    • getName

      public String getName()
      This will return the full name of the file without the path. As regargs the definition of the path in RFC 2396 the name would be considered the last path segment. So if the path was /usr/README the name is README. Also for directorys the name of the directory in the last path segment is returned. This returns the name without any of the path parameters. As RFC 2396 defines the path to have path parameters after the path segments.
      Specified by:
      getName in interface Path
      Returns:
      this will return the name of the file in the path

    • getPath

      public String getPath()
      This will return the normalized path. The normalized path is the path without any references to its parent or itself. So if the path to be parsed is /usr/../etc/./ the path is /etc/. If the path that this represents is a path with an immediate back reference then this will return null. This is the path with all its information even the parameter information if it was defined in the path.
      Specified by:
      getPath in interface Path
      Returns:
      this returns the normalize path without ../ or ./

    • getPath

      public String getPath(int from)
      This will return the normalized path from the specified path segment. This allows various path parts to be acquired in an efficient means what does not require copy operations of the use of substring invocations. Of particular interest is the extraction of context based paths. This is the path with all its information even the parameter information if it was defined in the path.
      Specified by:
      getPath in interface Path
      Parameters:
      from - this is the segment offset to get the path for
      Returns:
      this returns the normalize path without ../ or ./

    • getPath

      public String getPath(int from, int count)
      This will return the normalized path from the specified path segment. This allows various path parts to be acquired in an efficient means what does not require copy operations of the use of substring invocations. Of particular interest is the extraction of context based paths. This is the path with all its information even the parameter information if it was defined in the path.
      Specified by:
      getPath in interface Path
      Parameters:
      from - this is the segment offset to get the path for
      count - this is the number of path segments to include
      Returns:
      this returns the normalize path without ../ or ./

    • getDirectory

      public String getDirectory()
      This will return the highest directory that exists within the path. This is used to that files within the same path can be acquired. An example of that this would do given the path /pub/./bin/README would be to return the highest directory path /pub/bin/. The "/" character will allways be the last character in the path.
      Specified by:
      getDirectory in interface Path
      Returns:
      this method will return the highest directory

    • getSegments

      public String[] getSegments()
      This method is used to break the path into individual parts called segments, see RFC 2396. This can be used as an easy way to compare paths and to examine the directory tree that the path points to. For example, if an path was broken from the string /usr/bin/../etc then the segments returned would be usr and etc as the path is normalized before the segments are extracted.
      Specified by:
      getSegments in interface Path
      Returns:
      return all the path segments within the directory

    • getRelative

      public String getRelative(String path)
      This will return the path as it is relative to the issued path. This in effect will chop the start of this path if it's start matches the highest directory of the given path as of getDirectory. This is useful if paths that are relative to a specific location are required. To illustrate what this method will do the following example is provided. If this object represented the path string /usr/share/rfc/rfc2396.txt and the issued path was /usr/share/text.txt then this will return the path string /rfc/rfc2396.txt.
      Specified by:
      getRelative in interface Path
      Parameters:
      path - the path prefix to acquire a relative path
      Returns:
      returns a path relative to the one it is given otherwize this method will return null

    • getRelative

      private String getRelative(PathParser path)
      This is used by the getRelative(String) to normalize the path string and determine if it contains a highest directory which is shared with the path that is represented by this object. If the path has leading back references, such as ../, then the result of this is null. The returned path begins with a '/'.
      Parameters:
      path - the path prefix to acquire a relative path
      Returns:
      returns a path relative to the one it is given otherwize this method will return null

    • getRelative

      private String getRelative(char[] text, int off, int len)
      This will return the path as it is relative to the issued path. This in effect will chop the start of this path if it's start matches the highest directory of the given path as of getDirectory. This is useful if paths that are relative to a specific location are required. To illustrate what this method will do the following example is provided. If this object represented the path string /usr/share/rfc/rfc2396.txt and the issued path was /usr/share/text.txt then this will return the path string /rfc/rfc2396.txt.
      Parameters:
      text - the path prefix to acquire a relative path
      off - this is the offset within the text to read
      len - this is the number of characters in the path
      Returns:
      returns a path relative to the one it is given otherwize this method will return null

    • path

      private void path()
      This will extract the path of the given String after it has been normalized. If the path can not be normalized then the count is set to -1 and the path cannot be extracted. When this happens then the path parameter is null.

    • extension

      private void extension()
      This will simply read the characters from the end of the buffer until it encounters the first peroid character. When this is read it will store the file extension and remove the characters from the buffer.

    • segments

      private void segments()
      This wil extract each individual segment from the path and also extract the highest directory. The path segments are basically the strings delimited by the '/' character of a normalized path. As well as extracting the path segments this will also extract the directory of path, that is, the the path up to the last occurance of the '/' character.

    • normalize

      private void normalize()
      The normalization of the path is the conversion of the path given into it's actual path by removing the references to the parent directorys and to the current dir. So if the path given was /usr/bin/../etc/./README then the actual path, the normalized path, is /usr/etc/README.

      This method ensures the if there are an illegal number of back references that the path will be evaluated as empty. This can evaluate any path configuration, this includes any references like ../ or /.. within the path.

    • name

      private void name()
      This will extract the full name of the file without the path. As regards the definition of the path in RFC 2396 the name would be considered the last path segment. So if the path was /usr/README the name is README. Also for directorys the name of the directory in the last path segment is returned. This returns the name without any of the path parameters. As RFC 2396 defines the path to have path parameters after the path segments. So the path for the directory "/usr/bin;param=value/;param=value" would result in the name "bin". If the path given was "/" then there will be nothing in the buffer because extract will have removed it.

    • toString

      public String toString()
      This will return the normalized path. The normalized path is the path without any references to its parent or itself. So if the path to be parsed is /usr/../etc/./ the path is /etc/. If the path that this represents is a path with an immediate back reference then this will return null. This is the path with all its information even the parameter information if it was defined in the path.
      Specified by:
      toString in interface Path
      Overrides:
      toString in class Object
      Returns:
      this returns the normalize path without ../ or ./