Package com.sun.java.help.impl

Class XmlReader

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable
    public final class XmlReader
extends java.io.Reader
    This handles several XML-related tasks that normal java.io Readers don't support, inluding use of IETF standard encoding names and automatic detection of most XML encodings. The former is needed for interoperability; the latter is needed to conform with the XML spec. This class also optimizes reading some common encodings by providing low-overhead unsynchronized Reader support.

    Note that the autodetection facility should be used only on data streams which have an unknown character encoding. For example, it should never be used on MIME text/xml entities.

    Note that XML processors are only required to support UTF-8 and UTF-16 character encodings. Autodetection permits the underlying Java implementation to provide support for many other encodings, such as ISO-8859-5, Shift_JIS, EUC-JP, and ISO-2022-JP.

    • Field Summary

      • Fields inherited from class java.io.Reader

        lock

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()
      Closes the reader.
      static java.io.Reader createReader​(java.io.InputStream in)
      Constructs the reader from an input stream, autodetecting the encoding to use according to the heuristic specified in the XML 1.0 recommendation.
      static java.io.Reader createReader​(java.io.InputStream in, java.lang.String encoding)
      Creates a reader supporting the given encoding, mapping from standard encoding names to ones that understood by Java where necessary.
      static java.io.Reader createReader​(java.net.URLConnection uc)
      Constructs the reader from a URLConnection.
      java.lang.String getEncoding()
      Returns the (non)standard name of the encoding in use
      void mark​(int value)
      Sets a mark allowing a limited number of characters to be "peeked", by reading and then resetting.
      boolean markSupported()
      Returns true iff the reader supports mark/reset.
      int read()
      Reads a single character.
      int read​(char[] buf, int off, int len)
      Reads the number of characters read into the buffer, or -1 on EOF.
      boolean ready()
      Returns true iff input characters are known to be ready.
      void reset()
      Resets the current position to the last marked position.
      long skip​(long value)
      Skips a specified number of characters.

      • Methods inherited from class java.io.Reader

        nullReader, read, read, transferTo

      • Methods inherited from class java.lang.Object

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

    • Method Detail

      • createReader

        public static java.io.Reader createReader​(java.net.URLConnection uc)
                                   throws java.io.IOException
        Constructs the reader from a URLConnection. Uses the encoding specified in the HTTP header or autodetects the encoding to use according to the heuristic specified in the XML 1.0 recommendation.
        Parameters:
        uc - the URLConnection from which the reader is constructed
        Throws:
        java.io.IOException - on error
        java.io.UnsupportedEncodingException - when the input stream is not in an encoding which is supported; this is a fatal XML error.

      • createReader

        public static java.io.Reader createReader​(java.io.InputStream in)
                                   throws java.io.IOException
        Constructs the reader from an input stream, autodetecting the encoding to use according to the heuristic specified in the XML 1.0 recommendation.
        Parameters:
        in - the input stream from which the reader is constructed
        Throws:
        java.io.IOException - on error
        java.io.UnsupportedEncodingException - when the input stream is not in an encoding which is supported; this is a fatal XML error.

      • createReader

        public static java.io.Reader createReader​(java.io.InputStream in,
                                          java.lang.String encoding)
                                   throws java.io.IOException
        Creates a reader supporting the given encoding, mapping from standard encoding names to ones that understood by Java where necessary.
        Parameters:
        in - the input stream from which the reader is constructed
        encoding - the IETF standard name of the encoding to use; if null, autodetection is used.
        Throws:
        java.io.IOException - on error
        java.io.UnsupportedEncodingException - when the input stream is not in an encoding which is supported; this is a fatal XML error.

      • getEncoding

        public java.lang.String getEncoding()
        Returns the (non)standard name of the encoding in use

      • read

        public int read​(char[] buf,
                int off,
                int len)
         throws java.io.IOException
        Reads the number of characters read into the buffer, or -1 on EOF.
        Specified by:
        read in class java.io.Reader
        Throws:
        java.io.IOException

      • read

        public int read()
         throws java.io.IOException
        Reads a single character.
        Overrides:
        read in class java.io.Reader
        Throws:
        java.io.IOException

      • markSupported

        public boolean markSupported()
        Returns true iff the reader supports mark/reset.
        Overrides:
        markSupported in class java.io.Reader

      • mark

        public void mark​(int value)
          throws java.io.IOException
        Sets a mark allowing a limited number of characters to be "peeked", by reading and then resetting.
        Overrides:
        mark in class java.io.Reader
        Parameters:
        value - how many characters may be "peeked".
        Throws:
        java.io.IOException

      • reset

        public void reset()
           throws java.io.IOException
        Resets the current position to the last marked position.
        Overrides:
        reset in class java.io.Reader
        Throws:
        java.io.IOException

      • skip

        public long skip​(long value)
          throws java.io.IOException
        Skips a specified number of characters.
        Overrides:
        skip in class java.io.Reader
        Throws:
        java.io.IOException

      • ready

        public boolean ready()
              throws java.io.IOException
        Returns true iff input characters are known to be ready.
        Overrides:
        ready in class java.io.Reader
        Throws:
        java.io.IOException

      • close

        public void close()
           throws java.io.IOException
        Closes the reader.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Specified by:
        close in class java.io.Reader
        Throws:
        java.io.IOException