com.technia.tvc.core.util

Class CharsetUtils

java.lang.Object

com.technia.tvc.core.util.CharsetUtils

public final class CharsetUtils
extends java.lang.Object

Contains utility methods for detecting the character encoding (charset) used for an XML by scanning the Content-Type MIME/HTTP header or the XML prolog.

In the absence of information provided by an external transport protocol (e.g. HTTP or MIME), it is a fatal error for an entity including an encoding declaration to be presented to the XML processor in an encoding other than that named in the declaration, or for an entity which begins with neither a Byte Order Mark nor an encoding declaration to use an encoding other than UTF-8. Note that since ASCII is a subset of UTF-8, ordinary ASCII entities do not strictly need an encoding declaration.

Unless an encoding is determined by a higher-level protocol, it is also a fatal error if an XML entity contains no encoding declaration and its content is not legal UTF-8 or UTF-16.

Since:

4.1.0

Method Summary

Modifier and Type	Method and Description
static java.lang.String	fromContentType(javax.servlet.ServletRequest request) Returns the charset specified in the Content-Type header.
static java.lang.String	fromContentType(java.lang.String contentType) Returns the charset specified in the Content-Type header.
static java.lang.String	fromXMLProlog(byte[] xml) Scans the encoding specified in the XML prolog.
static java.io.InputStream	skipByteOrderMark(java.io.InputStream is) This method will remove (or read away) any byte order marks from the stream.

Methods inherited from class java.lang.Object

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

Method Detail

fromContentType

public static java.lang.String fromContentType(javax.servlet.ServletRequest request)

Returns the charset specified in the Content-Type header. If the header doesn't contain a charset parameter this method returns null.

Parameters:

request - The servlet request.

fromContentType

public static java.lang.String fromContentType(java.lang.String contentType)

Returns the charset specified in the Content-Type header. If the header doesn't contain a charset parameter this method returns null.

Parameters:

contentType - The header value.

fromXMLProlog

public static java.lang.String fromXMLProlog(byte[] xml)

Scans the encoding specified in the XML prolog. This method will return null if either the xml parameter is null or has zero length. References:

• http://www.w3.org/TR/REC-xml/#charencoding
• http://www.unicode.org/faq/utf_bom.html

Parameters:

xml - The bytes of the xml prolog (or the entire document).

skipByteOrderMark

public static java.io.InputStream skipByteOrderMark(java.io.InputStream is)
                                             throws java.io.IOException

This method will remove (or read away) any byte order marks from the stream. If no bom is found, nothing happens. Note that you need to use the returned InputStream to read from afterwards.

Parameters:

is - The inputstream to read from

Returns:

An InputStream that you should use to read the data from.

Throws:

java.io.IOException - If some error occurs while reading from the stream.

Since:

2014.1.0