dom4.jar包，高效xml解析

/* * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved. * * This software is open source. * See the bottom of this file for the licence. */ package org.dom4j.io; import java.io.BufferedWriter; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.UnsupportedEncodingException; import java.io.Writer; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.StringTokenizer; import org.dom4j.Attribute; import org.dom4j.CDATA; import org.dom4j.Comment; import org.dom4j.Document; import org.dom4j.DocumentType; import org.dom4j.Element; import org.dom4j.Entity; import org.dom4j.Namespace; import org.dom4j.Node; import org.dom4j.ProcessingInstruction; import org.dom4j.Text; import org.dom4j.tree.NamespaceStack; import org.xml.sax.Attributes; import org.xml.sax.InputSource; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.SAXNotRecognizedException; import org.xml.sax.SAXNotSupportedException; import org.xml.sax.XMLReader; import org.xml.sax.ext.LexicalHandler; import org.xml.sax.helpers.XMLFilterImpl; /** * <p> * <code>XMLWriter</code> takes a DOM4J tree and formats it to a stream as * XML. It can also take SAX events too so can be used by SAX clients as this * object implements the {@link org.xml.sax.ContentHandler}and {@link * LexicalHandler} interfaces. as well. This formatter performs typical document * formatting. The XML declaration and processing instructions are always on * their own lines. An {@link OutputFormat}object can be used to define how * whitespace is handled when printing and allows various configuration options, * such as to allow suppression of the XML declaration, the encoding declaration * or whether empty documents are collapsed. * </p> * * <p> * There are <code>write(...)</code> methods to print any of the standard * DOM4J classes, including <code>Document</code> and <code>Element</code>, * to either a <code>Writer</code> or an <code>OutputStream</code>. * Warning: using your own <code>Writer</code> may cause the writer's * preferred character encoding to be ignored. If you use encodings other than * UTF8, we recommend using the method that takes an OutputStream instead. * </p> * * @author <a href="mailto:jstrachan@apache.org">James Strachan </a> * @author Joseph Bowbeer * @version $Revision: 1.83.2.2 $ */ public class XMLWriter extends XMLFilterImpl implements LexicalHandler { private static final String PAD_TEXT = " "; protected static final String[] LEXICAL_HANDLER_NAMES = { "http://xml.org/sax/properties/lexical-handler", "http://xml.org/sax/handlers/LexicalHandler"}; protected static final OutputFormat DEFAULT_FORMAT = new OutputFormat(); /** Should entityRefs by resolved when writing ? */ private boolean resolveEntityRefs = true; /** * Stores the last type of node written so algorithms can refer to the * previous node type */ protected int lastOutputNodeType; /** * Stores if the last written element node was a closing tag or an opening * tag. */ private boolean lastElementClosed = false; /** Stores the xml:space attribute value of preserve for whitespace flag */ protected boolean preserve = false; /** The Writer used to output to */ protected Writer writer; /** The Stack of namespaceStack written so far */ private NamespaceStack namespaceStack = new NamespaceStack(); /** The format used by this writer */ private OutputFormat format; /** whether we should escape text */ private boolean escapeText = true; /** * The initial number of indentations (so you can print a whole document * indented, if you like) */ private int indentLevel = 0; /** buffer used when escaping strings */ private StringBuffer buffer = new StringBuffer(); /** * whether we have added characters before from the same chunk of characters */ private boolean charsAdded = false; private char lastChar; /** Whether a flush should occur after writing a document */ private boolean autoFlush; /** Lexical handler we should delegate to */ private LexicalHandler lexicalHandler; /** * Whether comments should appear inside DTD declarations - defaults to * false */ private boolean showCommentsInDTDs; /** Is the writer curerntly inside a DTD definition? */ private boolean inDTD; /** The namespaces used for the current element when consuming SAX events */ private Map namespacesMap; /** * what is the maximum allowed character code such as 127 in US-ASCII (7 * bit) or 255 in ISO- (8 bit) or -1 to not escape any characters (other * than the special XML characters like &lt; &gt; &amp;) */ private int maximumAllowedCharacter; public XMLWriter(Writer writer) { this(writer, DEFAULT_FORMAT); } public XMLWriter(Writer writer, OutputFormat format) { this.writer = writer; this.format = format; namespaceStack.push(Namespace.NO_NAMESPACE); } public XMLWriter() { this.format = DEFAULT_FORMAT; this.writer = new BufferedWriter(new OutputStreamWriter(System.out)); this.autoFlush = true; namespaceStack.push(Namespace.NO_NAMESPACE); } public XMLWriter(OutputStream out) throws UnsupportedEncodingException { this.format = DEFAULT_FORMAT; this.writer = createWriter(out, format.getEncoding()); this.autoFlush = true; namespaceStack.push(Namespace.NO_NAMESPACE); } public XMLWriter(OutputStream out, OutputFormat format) throws UnsupportedEncodingException { this.format = format; this.writer = createWriter(out, format.getEncoding()); this.autoFlush = true; namespaceStack.push(Namespace.NO_NAMESPACE); } public XMLWriter(OutputFormat format) throws UnsupportedEncodingException { this.format = format; this.writer = createWriter(System.out, format.getEncoding()); this.autoFlush = true; namespaceStack.push(Namespace.NO_NAMESPACE); } public void setWriter(Writer writer) { this.writer = writer; this.autoFlush = false; } public void setOutputStream(OutputStream out) throws UnsupportedEncodingException { this.writer = createWriter(out, format.getEncoding()); this.autoFlush = true; } /** * DOCUMENT ME! * * @return true if text thats output should be escaped. This is enabled by * default. It could be disabled if the output format is textual, * like in XSLT where we can have xml, html or text output. */ public boolean isEscapeText() { return escapeText; } /** * Sets whether text output should be escaped or not. This is enabled by * default. It could be disabled if the output format is textual, like in * XSLT where we can have xml, html or text output. * * @param escapeText * DOCUMENT ME! */ public void setEscapeText(boolean escapeText) { this.escapeText = escapeText; } /** * Set the initial indentation level. This can be used to output a document * (or, more likely, an element) starting at a given indent level, so it's * not always flush against the left margin. Default: 0 * * @param indentLevel * the number of indents to start with */ public void setIndentLevel(int indentLevel) { this.indentLevel = indentLevel; } /** * Returns