Package wt.util

Class EncodingConverter

java.lang.Object
java.io.OutputStream
java.io.ByteArrayOutputStream
wt.util.EncodingConverter
All Implemented Interfaces:
Closeable, Flushable, AutoCloseable
Direct Known Subclasses:
EncodingConverter
public class EncodingConverter extends ByteArrayOutputStream
The class contains utility methods for converting a String into a MIME format called "x-www-form-urlencoded" and vice versa.

To convert a String, each character is examined in turn:

  • The ASCII characters 'a' through 'z', 'A' through 'Z', and '0' through '9' remain the same.
  • The space character ' ' is converted into a plus sign '+'.
  • All other characters are converted into an 8-bit byte sequence using a character encoding and the resulting bytes are each represented as a 3-character string "%xy", where xy is the two-digit hexadecimal representation of the byte.


Deployment Notes:

    The EncodingConverter is a replacement for WTURLEncoder and is instance based. The EncodingConverter should not be shared amongst threads or used as a static instance unless appropriate synchronization blocks are used to protect the internal buffers from overrighting. This can be done one of two ways. Firstly by declaring the method which calls the encode/decode methods as synchronized, or by placing a syncrhonized block around the actually calls to encode/decode as shown below.



      static EncodingConverter staticEncoder = new EncodingConverter();

      public void sampleMethod(String s)
      {
        synchronized( staticEncoder )
        {
          staticEncoder.encode(s);
        }
      }



Supported API: true
Extendable: false

  • Constructor Details

    • EncodingConverter

      public EncodingConverter()
      Consturctor to create a new EncodingConverter with the encoding set to UTF-8.

      Supported API: true

    • EncodingConverter

      public EncodingConverter(int ByteSize)
      Constructor to create a new EncodingConverter with an encoding set to UTF-8 and a specified buffer capacity.

      Supported API: true

      Parameters:
      ByteSize - The buffer capacity.

    • EncodingConverter

      public EncodingConverter(String encoding)
      Constructor to create a new EncodingConverter with a specified encoding.

      Supported API: true
      Parameters:
      encoding - The encoding to use for encode/decoding.

  • Method Details

    • encode

      public String encode(String s)
      Translates a string into x-www-form-urlencoded format. Hex escaped characters are first encoded using UTF8 character encoding before Hex escaping the resulting bytes. This produces an encoded string that can be decoded without loss of data.

      Thread Safe: true (not if shared between thread)

      Supported API: true
      Parameters:
      s - String to be translated.
      Returns:
      the translated String.

    • encode

      public String encode(String s, String encoding)
      Translates a string into x-www-form-urlencoded format. Hex escaped characters are first encoded using the given character encoding before Hex escaping the resulting bytes.

      Thread Safe: true (not if shared between thread)

      Supported API: true
      Parameters:
      s - String to be translated.
      encoding - the character encoding name
      Returns:
      the translated String, or "" if the string s was null.

    • encode

      public void encode(StringBuffer buf, String s)
      Translates a string into x-www-form-urlencoded format. Hex escaped characters are first encoded using UTF8 character encoding before Hex escaping the resulting bytes. This produces an encoded string that can be decoded without loss of data.

      Thread Safe: true (not if shared between thread)

      Supported API: true
      Parameters:
      buf - StringBuffer to receive encoded characters.
      s - String to be translated.

    • encode

      public void encode(StringBuffer buf, String s, String encoding)
      Translates a string into x-www-form-urlencoded format. Hex escaped characters are first encoded using the given character encoding before Hex escaping the resulting bytes.

      Thread Safe: true (not if shared between thread)

      Supported API: true
      Parameters:
      buf - StringBuffer to receive encoded characters.
      s - String to be translated.
      encoding - the character encoding name

    • escape

      public static String escape(String str)
      Escape special characters in accordance with URL path segment encoding requirements. Replaces spaces with %20 and double quotes with %22. In theory, all special characters should be URLEncoded, but the 4.x browsers don't interpret the file name correctly using their native character encoding when that is done.

      Supported API: true
      Parameters:
      str - String to escape.
      Returns:
      Escaped string value.

    • decode

      public String decode(String s)
      Translates a string from x-www-form-urlencoded format back into a string. Hex escaped bytes are converted and the resulting sequence of 8-bit values is converted to characters using UTF8 encoding. This produces a decoded string from the results of encode without loss data.

      Thread Safe: true (not if shared between thread)

      Supported API: true
      Parameters:
      s - String to be translated.
      Returns:
      the translated String.

    • decode

      public String decode(String encoded, String encoding)
      Translates a string from x-www-form-urlencoded format back the original string. Hex escaped bytes are converted and the resulting sequence of 8-bit values is converted to characters using the given character encoding.

      Thread Safe: true (not if shared between thread)

      Supported API: true
      Parameters:
      encoded - String to be translated.
      encoding - the character encoding name
      Returns:
      the translated String or "" if encoded is null.

    • decodeBytes

      public static final String decodeBytes(String str) throws UnsupportedEncodingException
      Convience method to convert the bytes of a String in ISO-8859_1 encoding to UTF-8 encoding. This should typically be called after a JSP request.getParameter( ) call.

      Supported API: true
      Parameters:
      str - The string to re-encode for the correct bytes.
      Returns:
      String the decoded and translated String.
      Throws:
      UnsupportedEncodingException

    • decodeBytes

      public static final String decodeBytes(String str, String enc) throws UnsupportedEncodingException
      Convience method to convert the bytes of a String in ISO-8859_1 encoding to a designated encoding. This should typically be called after a JSP request.getParameter( ) call.

      Supported API: true
      Parameters:
      str - The string to re-encode for the correct bytes.
      enc - The encoding to translate to.
      Returns:
      String the decoded and translated String.
      Throws:
      UnsupportedEncodingException

    • decodeBytes

      public static final String decodeBytes(String str, String from_enc, String to_enc) throws UnsupportedEncodingException
      Convience method to convert the bytes of a String in an input encoding encoding to a designated encoding. This should typically be called after a JSP request.getParameter( ) call.

      Supported API: true
      Parameters:
      str - The string to re-encode for the correct bytes.
      from_enc - The encoding coming from.
      to_enc - The encoding to translate to.
      Returns:
      String the decoded and translated String.
      Throws:
      UnsupportedEncodingException