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package com.ctc.wstx.api;
import java.io.IOException;
/**
* Simple converter interface designed to be used with stream writer property
* {@link WstxOutputProperties#P_OUTPUT_INVALID_CHAR_HANDLER}.
* The idea is that it should be easy to have a way to convert invalid
* characters such as Ascii control characters into something that
* is legal to include in XML content. This only allows for simple
* char-by-char replacements, instead of something more advanced such
* as escaping. If escaping is needed, check out
* {@link org.codehaus.stax2.XMLOutputFactory2#P_TEXT_ESCAPER} instead.
*
* Note about exceptions: choice of only allowing throwing of
* {@link IOException}s is due to the way Woodstox stream writer
* backend works; XmlWriter can only throw IOExceptions.
*/
public interface InvalidCharHandler
{
public char convertInvalidChar(int invalidChar) throws IOException;
/**
* This handler implementation just throws an exception for
* all invalid characters encountered. It is the default handler
* used if nothing else has been specified.
*/
public static class FailingHandler
implements InvalidCharHandler
{
public final static int SURR1_FIRST = 0xD800;
public final static int SURR1_LAST = 0xDBFF;
public final static int SURR2_FIRST = 0xDC00;
public final static int SURR2_LAST = 0xDFFF;
private final static FailingHandler sInstance = new FailingHandler();
protected FailingHandler() { }
public static FailingHandler getInstance() { return sInstance; }
public char convertInvalidChar(int c) throws IOException
{
/* 17-May-2006, TSa: Would really be useful if we could throw
* XMLStreamExceptions; esp. to indicate actual output location.
* However, this causes problem with methods that call us and
* can only throw IOExceptions (when invoked via Writer proxy).
* Need to figure out how to resolve this.
*/
if (c == 0) {
throw new IOException("Invalid null character in text to output");
}
if (c < ' ' || (c >= 0x7F && c <= 0x9F)) {
String msg = "Invalid white space character (0x"+Integer.toHexString(c)+") in text to output (in xml 1.1, could output as a character entity)";
throw new IOException(msg);
}
if (c > 0x10FFFF) {
throw new IOException("Illegal unicode character point (0x"+Integer.toHexString(c)+") to output; max is 0x10FFFF as per RFC 3629");
}
/* Surrogate pair in non-quotable (not text or attribute value)
* content, and non-unicode encoding (ISO-8859-x, Ascii)?
*/
if (c >= SURR1_FIRST && c <= SURR2_LAST) {
throw new IOException("Illegal surrogate pair -- can only be output via character entities, which are not allowed in this content");
}
throw new IOException("Invalid XML character (0x"+Integer.toHexString(c)+") in text to output");
}
}
/**
* Alternative to the default handler, this handler converts all invalid
* characters to the specified output character. That character will
* not be further verified or modified by the stream writer.
*/
public static class ReplacingHandler
implements InvalidCharHandler
{
final char mReplacementChar;
public ReplacingHandler(char c)
{
mReplacementChar = c;
}
public char convertInvalidChar(int c) throws IOException
{
return mReplacementChar;
}
}
}