Java tutorial
/* * Copyright 1999-2004 The Apache Software Foundation. * * 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 org.apache.cocoon.components.serializers; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.UnsupportedEncodingException; import java.util.Arrays; import org.apache.avalon.excalibur.pool.Recyclable; import org.apache.avalon.framework.configuration.Configurable; import org.apache.avalon.framework.configuration.Configuration; import org.apache.avalon.framework.configuration.ConfigurationException; import org.apache.cocoon.components.serializers.encoding.Charset; import org.apache.cocoon.components.serializers.encoding.CharsetFactory; import org.apache.cocoon.components.serializers.encoding.Encoder; import org.apache.cocoon.components.serializers.util.Namespaces; import org.apache.cocoon.serialization.Serializer; import org.apache.commons.lang.SystemUtils; import org.xml.sax.Attributes; import org.xml.sax.Locator; import org.xml.sax.SAXException; /** * <p>An abstract serializer supporting multiple encodings.</p> * * <p>This serializer can accept the following configuration whenever it * is declared into a sitemap:</p> * * <pre> * <serializer class="org.apache.cocoon.components.serializers..." ... > * <encoding>myencoding</encoding> * <indent>myindenting</indent> * </serializer> * </pre> * * <p>The value indicated by <i>myencoding</i> must be replaced with a valid * charset encoding (this serializer does not rely on the JVM for character * encoding, you can look into the <code>cocoon-serializers-charsets</code> * JAR file for a list).<p> * * <p>The value indicated by <i>myindenting</i> will control the indenting * level for each element.<p> * * @version CVS $Id: EncodingSerializer.java 376354 2006-02-09 17:17:45Z pier $ */ public abstract class EncodingSerializer implements Serializer, Locator, Recyclable, Configurable { /** The line separator string */ private static final char S_EOL[] = SystemUtils.LINE_SEPARATOR.toCharArray(); /* ====================================================================== */ /** The position of the namespace URI in the attributes array. */ public static final int ATTRIBUTE_NSURI = 0; /** The position of the local name in the attributes array. */ public static final int ATTRIBUTE_LOCAL = 1; /** The position of the qualified name in the attributes array. */ public static final int ATTRIBUTE_QNAME = 2; /** The position of the value in the attributes array. */ public static final int ATTRIBUTE_VALUE = 3; /** The length of the array of strings representing an attribute. */ public static final int ATTRIBUTE_LENGTH = 4; /* ====================================================================== */ /** Our <code>Encoder</code> instance. */ private Encoder encoder = null; /** Our <code>Locator</code> instance. */ private Locator locator = null; /** Our <code>Writer</code> instance. */ private OutputStreamWriter out = null; /** Flag indicating if the document prolog is being processed. */ private boolean prolog = true; /** Flag indicating if the document is being processed. */ private boolean processing = false; /** Current nesting level */ private int level = 0; /** Whitespace buffer for indentation */ private char[] indentBuffer = null; /* ====================================================================== */ /** The <code>Charset</code> associated with the character encoding. */ protected Charset charset = null; /** The <code>Namespace</code> associated with this instance. */ protected Namespaces namespaces = new Namespaces(); /** Per level indent spaces */ protected int indentPerLevel = 0; /* ====================================================================== */ /** * Create a new instance of this <code>EncodingSerializer</code> */ protected EncodingSerializer(Encoder encoder) { super(); this.encoder = encoder; this.recycle(); } /* ====================================================================== */ /** * Test if the component wants to set the content length. */ public boolean shouldSetContentLength() { return (false); } /** * Reset this <code>EncodingSerializer</code>. */ public void recycle() { if (processing) throw new IllegalStateException(); this.namespaces = new Namespaces(); this.locator = null; this.out = null; this.prolog = true; } /** * Set the <code>OutputStream</code> where this serializer will * write data to. * * @param out The <code>OutputStream</code> used for output. */ public void setOutputStream(OutputStream out) throws IOException { if (out == null) throw new NullPointerException("Null output"); this.out = new OutputStreamWriter(out, this.charset.getName()); } /** * Set the configurations for this serializer. */ public void configure(Configuration conf) throws ConfigurationException { String encoding = conf.getChild("encoding").getValue(null); try { this.charset = CharsetFactory.newInstance().getCharset(encoding); } catch (UnsupportedEncodingException exception) { throw new ConfigurationException("Encoding not supported: " + encoding, exception); } indentPerLevel = conf.getChild("indent").getValueAsInteger(0); if (indentPerLevel > 0) { assureIndentBuffer(indentPerLevel * 6); } } /* ====================================================================== */ private char[] assureIndentBuffer(int size) { if (indentBuffer == null || indentBuffer.length < size) { indentBuffer = new char[size]; Arrays.fill(indentBuffer, ' '); } return indentBuffer; } /** * Encode and write a <code>String</code> */ protected void encode(String data) throws SAXException { char array[] = data.toCharArray(); this.encode(array, 0, array.length); } /** * Encode and write an array of characters. */ protected void encode(char data[]) throws SAXException { this.encode(data, 0, data.length); } /** * Encode and write a specific part of an array of characters. */ protected void encode(char data[], int start, int length) throws SAXException { int end = start + length; if (data == null) throw new NullPointerException("Null data"); if ((start < 0) || (start > data.length) || (length < 0) || (end > data.length) || (end < 0)) throw new IndexOutOfBoundsException("Invalid data"); if (length == 0) return; for (int x = start; x < end; x++) { char c = data[x]; if (this.charset.allows(c) && this.encoder.allows(c)) { continue; } if (start != x) this.write(data, start, x - start); this.write(this.encoder.encode(c)); start = x + 1; continue; } if (start != end) this.write(data, start, end - start); } /* ====================================================================== */ /** * Receive an object for locating the origin of SAX document events. */ public final void setDocumentLocator(Locator locator) { this.locator = locator; } /** * Return the public identifier for the current document event. * * @return A <code>String</code> containing the public identifier, * or <b>null</b> if none is available. */ public String getPublicId() { return (this.locator == null ? null : this.locator.getPublicId()); } /** * Return the system identifier for the current document event. * * @return A <code>String</code> containing the system identifier, * or <b>null</b> if none is available. */ public String getSystemId() { return (this.locator == null ? null : this.locator.getSystemId()); } /** * Return the line number where the current document event ends. * * @return The line number, or -1 if none is available. */ public int getLineNumber() { return (this.locator == null ? -1 : this.locator.getLineNumber()); } /** * Return the column number where the current document event ends. * * @return The column number, or -1 if none is available. */ public int getColumnNumber() { return (this.locator == null ? -1 : this.locator.getColumnNumber()); } /** * Return a <code>String</code> describing the current location. */ protected String getLocation() { if (this.locator == null) return (""); StringBuffer buf = new StringBuffer(" ("); if (this.getSystemId() != null) { buf.append(this.getSystemId()); buf.append(' '); } buf.append("line " + this.getLineNumber()); buf.append(" col " + this.getColumnNumber()); buf.append(')'); return (buf.toString()); } /* ====================================================================== */ /** * Flush the stream. */ protected void flush() throws SAXException { try { this.out.flush(); } catch (IOException e) { throw new SAXException("I/O error flushing: " + e.getMessage(), e); } } /** * Write an array of characters. */ protected void write(char data[]) throws SAXException { try { this.out.write(data, 0, data.length); } catch (IOException e) { throw new SAXException("I/O error writing: " + e.getMessage(), e); } } /** * Write a portion of an array of characters. */ protected void write(char data[], int start, int length) throws SAXException { try { this.out.write(data, start, length); } catch (IOException e) { throw new SAXException("I/O error writing: " + e.getMessage(), e); } } /** * Write a single character. */ protected void write(int c) throws SAXException { try { this.out.write(c); } catch (IOException e) { throw new SAXException("I/O error writing: " + e.getMessage(), e); } } /** * Write a string. */ protected void write(String data) throws SAXException { try { this.out.write(data); } catch (IOException e) { throw new SAXException("I/O error writing: " + e.getMessage(), e); } } /** * Write a portion of a string. */ protected void write(String data, int start, int length) throws SAXException { try { this.out.write(data, start, length); } catch (IOException e) { throw new SAXException("I/O error writing: " + e.getMessage(), e); } } /** * Write a end-of-line character. */ protected void writeln() throws SAXException { try { this.out.write(S_EOL); } catch (IOException e) { throw new SAXException("I/O error writing: " + e.getMessage(), e); } } /** * Write a string and a end-of-line character. */ protected void writeln(String data) throws SAXException { try { this.out.write(data); this.out.write(S_EOL); } catch (IOException e) { throw new SAXException("I/O error writing: " + e.getMessage(), e); } } /** * Write out character to indent the output according * to the level of nesting * @param indent * @throws SAXException */ protected void writeIndent(int indent) throws SAXException { this.charactersImpl("\n".toCharArray(), 0, 1); if (indent > 0) { this.charactersImpl(assureIndentBuffer(indent), 0, indent); } } /* ====================================================================== */ /** * Receive notification of the beginning of a document. */ public void startDocument() throws SAXException { this.processing = true; this.level = 0; } /** * Receive notification of the end of a document. */ public void endDocument() throws SAXException { this.processing = false; this.flush(); } /** * Begin the scope of a prefix-URI Namespace mapping. */ public void startPrefixMapping(String prefix, String uri) throws SAXException { this.namespaces.push(prefix, uri); } /** * End the scope of a prefix-URI mapping. */ public void endPrefixMapping(String prefix) throws SAXException { this.namespaces.pop(prefix); } /** * Receive notification of the beginning of an element. */ public void startElement(String nsuri, String local, String qual, Attributes attributes) throws SAXException { if (indentPerLevel > 0) { this.writeIndent(indentPerLevel * level); level++; } String name = this.namespaces.qualify(nsuri, local, qual); if (this.prolog) { this.body(nsuri, local, name); this.prolog = false; } String ns[][] = this.namespaces.commit(); String at[][] = new String[attributes.getLength()][4]; for (int x = 0; x < at.length; x++) { at[x][ATTRIBUTE_NSURI] = attributes.getURI(x); at[x][ATTRIBUTE_LOCAL] = attributes.getLocalName(x); at[x][ATTRIBUTE_QNAME] = namespaces.qualify(attributes.getURI(x), attributes.getLocalName(x), attributes.getQName(x)); at[x][ATTRIBUTE_VALUE] = attributes.getValue(x); } this.startElementImpl(nsuri, local, name, ns, at); } public void characters(char ch[], int start, int length) throws SAXException { if (indentPerLevel > 0) { this.writeIndent(indentPerLevel * level + 1); } this.charactersImpl(ch, start, length); } /** * Receive notification of the end of an element. */ public void endElement(String nsuri, String local, String qual) throws SAXException { if (indentPerLevel > 0) { level--; this.writeIndent(indentPerLevel * level); } String name = this.namespaces.qualify(nsuri, local, qual); this.endElementImpl(nsuri, local, name); } /** * Receive notification of the beginning of the document body. * * @param uri The namespace URI of the root element. * @param local The local name of the root element. * @param qual The fully-qualified name of the root element. */ public abstract void body(String uri, String local, String qual) throws SAXException; /** * Receive notification of the beginning of an element. * * @param uri The namespace URI of the root element. * @param local The local name of the root element. * @param qual The fully-qualified name of the root element. * @param namespaces An array of <code>String</code> objects containing * the namespaces to be declared by this element. * @param attributes An array of <code>String</code> objects containing * all attributes of this element. */ public abstract void startElementImpl(String uri, String local, String qual, String namespaces[][], String attributes[][]) throws SAXException; /** * Receive character notifications * @param ch * @param start * @param length * @throws SAXException */ public abstract void charactersImpl(char ch[], int start, int length) throws SAXException; /** * Receive notification of the end of an element. * * @param uri The namespace URI of the root element. * @param local The local name of the root element. * @param qual The fully-qualified name of the root element. */ public abstract void endElementImpl(String uri, String local, String qual) throws SAXException; }