private Reader createReader()

in src/main/java/org/apache/sling/scripting/jsp/jasper/xmlparser/XMLEncodingDetector.java [201:274]
56 lines of code
15 McCabe index (conditional complexity)

    private Reader createReader(InputStream inputStream, String encoding,
				Boolean isBigEndian)
                throws IOException, JasperException {

        // normalize encoding name
        if (encoding == null) {
            encoding = "UTF-8";
        }

        // try to use an optimized reader
        String ENCODING = encoding.toUpperCase(Locale.ENGLISH);
        if (ENCODING.equals("UTF-8")) {
            return new UTF8Reader(inputStream, fBufferSize);
        }
        if (ENCODING.equals("US-ASCII")) {
            return new ASCIIReader(inputStream, fBufferSize);
        }
        if (ENCODING.equals("ISO-10646-UCS-4")) {
            if (isBigEndian != null) {
                boolean isBE = isBigEndian.booleanValue();
                if (isBE) {
                    return new UCSReader(inputStream, UCSReader.UCS4BE);
                } else {
                    return new UCSReader(inputStream, UCSReader.UCS4LE);
                }
            } else {
                err.jspError("jsp.error.xml.encodingByteOrderUnsupported",
			     encoding);
            }
        }
        if (ENCODING.equals("ISO-10646-UCS-2")) {
            if (isBigEndian != null) { // sould never happen with this encoding...
                boolean isBE = isBigEndian.booleanValue();
                if (isBE) {
                    return new UCSReader(inputStream, UCSReader.UCS2BE);
                } else {
                    return new UCSReader(inputStream, UCSReader.UCS2LE);
                }
            } else {
                err.jspError("jsp.error.xml.encodingByteOrderUnsupported",
			     encoding);
            }
        }

        // check for valid name
        boolean validIANA = XMLChar.isValidIANAEncoding(encoding);
        boolean validJava = XMLChar.isValidJavaEncoding(encoding);
        if (!validIANA || (fAllowJavaEncodings && !validJava)) {
            err.jspError("jsp.error.xml.encodingDeclInvalid", encoding);
            // NOTE: AndyH suggested that, on failure, we use ISO Latin 1
            //       because every byte is a valid ISO Latin 1 character.
            //       It may not translate correctly but if we failed on
            //       the encoding anyway, then we're expecting the content
            //       of the document to be bad. This will just prevent an
            //       invalid UTF-8 sequence to be detected. This is only
            //       important when continue-after-fatal-error is turned
            //       on. -Ac
            encoding = "ISO-8859-1";
        }

        // try to use a Java reader
        String javaEncoding = EncodingMap.getIANA2JavaMapping(ENCODING);
        if (javaEncoding == null) {
            if (fAllowJavaEncodings) {
		javaEncoding = encoding;
            } else {
                err.jspError("jsp.error.xml.encodingDeclInvalid", encoding);
                // see comment above.
                javaEncoding = "ISO8859_1";
            }
        }
        return new InputStreamReader(inputStream, javaEncoding);

    } // createReader(InputStream,String, Boolean): Reader