Groovy example source code file (StreamingMarkupWriter.java)

This example Groovy source code file (StreamingMarkupWriter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

encodingawarebufferedwriter, io, ioexception, ioexception, low, outputstreamwriter, streamingmarkupwriter, streamingmarkupwriter, string, string, stringbuffer, surrogate, us-ascii, writer, writer

The Groovy StreamingMarkupWriter.java source code

/*
 * Copyright 2003-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package groovy.xml.streamingmarkupsupport;

import groovy.io.EncodingAwareBufferedWriter;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;

public class StreamingMarkupWriter extends Writer {
    protected final Writer writer;
    protected final String encoding;
    protected boolean encodingKnown;
    protected final CharsetEncoder encoder;
    protected boolean writingAttribute = false;
    protected boolean haveHighSurrogate = false;
    protected StringBuffer surrogatePair = new StringBuffer(2);
    private boolean useDoubleQuotes;
    private final Writer escapedWriter = new Writer() {
        /* (non-Javadoc)
        * @see java.io.Writer#close()
        */
        public void close() throws IOException {
            StreamingMarkupWriter.this.close();
        }

        /* (non-Javadoc)
        * @see java.io.Writer#flush()
        */
        public void flush() throws IOException {
            StreamingMarkupWriter.this.flush();
        }

        /* (non-Javadoc)
        * @see java.io.Writer#write(int)
        */
        public void write(final int c) throws IOException {
            if (c == '<') {
                StreamingMarkupWriter.this.writer.write("<");
            } else if (c == '>') {
                StreamingMarkupWriter.this.writer.write(">");
            } else if (c == '&') {
                StreamingMarkupWriter.this.writer.write("&");
            } else {
                StreamingMarkupWriter.this.write(c);
            }
        }

        /* (non-Javadoc)
        * @see java.io.Writer#write(char[], int, int)
        */
        public void write(final char[] cbuf, int off, int len) throws IOException {
            while (len-- > 0) {
                write(cbuf[off++]);
            }
        }

        public void setWritingAttribute(final boolean writingAttribute) {
            StreamingMarkupWriter.this.writingAttribute = writingAttribute;
        }

        public Writer excaped() {
            return escapedWriter;
        }

        public Writer unescaped() {
            return StreamingMarkupWriter.this;
        }
    };

    public StreamingMarkupWriter(final Writer writer, final String encoding) {
        this(writer, encoding, false);
    }

    public StreamingMarkupWriter(final Writer writer, final String encoding, boolean useDoubleQuotes) {
        this.useDoubleQuotes = useDoubleQuotes;
        this.writer = writer;

        if (encoding != null) {
            this.encoding = encoding;
            this.encodingKnown = true;
        } else if (writer instanceof OutputStreamWriter) {
            this.encoding = getNormalizedEncoding(((OutputStreamWriter) writer).getEncoding());
            this.encodingKnown = true;
        } else if (writer instanceof EncodingAwareBufferedWriter) {
            this.encoding = getNormalizedEncoding(((EncodingAwareBufferedWriter) writer).getEncoding());
            this.encodingKnown = true;
        } else {
            this.encoding = "US-ASCII";
            this.encodingKnown = false;
        }

        this.encoder = Charset.forName(this.encoding).newEncoder();
    }

    private String getNormalizedEncoding(String unnormalized) {
        return Charset.forName(unnormalized).name();
    }

    public StreamingMarkupWriter(final Writer writer) {
        this(writer, null);
    }

    /* (non-Javadoc)
    * @see java.io.Writer#close()
    */
    public void close() throws IOException {
        this.writer.close();
    }

    /* (non-Javadoc)
    * @see java.io.Writer#flush()
    */
    public void flush() throws IOException {
        this.writer.flush();
    }

    /* (non-Javadoc)
    * @see java.io.Writer#write(int)
    */
    public void write(final int c) throws IOException {
        if (c >= 0XDC00 && c <= 0XDFFF) {
            // Low surrogate
            this.surrogatePair.append((char) c);

            if (this.encoder.canEncode(this.surrogatePair)) {
                this.writer.write(this.surrogatePair.toString());
            } else {
                this.writer.write("&#x");
                this.writer.write(Integer.toHexString(0X10000 + ((this.surrogatePair.charAt(0) & 0X3FF) << 10) + (c & 0X3FF)));
                this.writer.write(';');
            }

            this.haveHighSurrogate = false;
            this.surrogatePair.setLength(0);
        } else {
            if (this.haveHighSurrogate) {
                this.haveHighSurrogate = false;
                this.surrogatePair.setLength(0);
                throw new IOException("High Surrogate not followed by Low Surrogate");
            }

            if (c >= 0XD800 && c <= 0XDBFF) {
                // High surrogate
                this.surrogatePair.append((char) c);
                this.haveHighSurrogate = true;

            } else if (!this.encoder.canEncode((char) c)) {
                this.writer.write("&#x");
                this.writer.write(Integer.toHexString(c));
                this.writer.write(';');
            } else if (c == '\'' && this.writingAttribute && !useDoubleQuotes) {
                this.writer.write("'");
            } else if (c == '"' && this.writingAttribute && useDoubleQuotes) {
                this.writer.write(""");
            } else if (c == '\n' && this.writingAttribute) {
                this.writer.write("
");
            } else if (c == '\r' && this.writingAttribute) {
                this.writer.write("
");
            } else if (c == '\t' && this.writingAttribute) {
                this.writer.write("	");
            } else {
                this.writer.write(c);
            }
        }
    }

    /* (non-Javadoc)
    * @see java.io.Writer#write(char[], int, int)
    */
    public void write(final char[] cbuf, int off, int len) throws IOException {
        while (len-- > 0) {
            write(cbuf[off++]);
        }
    }

    public void setWritingAttribute(final boolean writingAttribute) {
        this.writingAttribute = writingAttribute;
    }

    public Writer escaped() {
        return this.escapedWriter;
    }

    public Writer unescaped() {
        return this;
    }

    public String getEncoding() {
        return this.encoding;
    }

    public boolean getEncodingKnown() {
        return this.encodingKnown;
    }
}