关于import导入库的问题

[youhaodeyi]

我用import 导入了一个库：
import com.sun.org.apache.xerces.internal.parsers.DOMParser;
程序可以使用类DOMParser，但是我在java sdk文档中找不到这个类的定义，这是为什么呢？

[sxnucseven]

这个库不是j2se里的

[sxnucseven]

在你下这个包的时候应该有带着他的文档

[88324877]

你试试 单独导如入包中的一个类看看。

[youhaodeyi]

这个包我没有安过呀！他是如何找到的呢？

[youhaodeyi]

这个包我没有安装过呀！我在任意一个机器上都可以导入这个类的。

[youhaodeyi]

高手帮帮忙

[m0317045]

package com.sun.org.apache.xerces.internal.parsers;

import java.io.IOException;

import com.sun.org.apache.xerces.internal.impl.Constants;
import com.sun.org.apache.xerces.internal.util.EntityResolverWrapper;
import com.sun.org.apache.xerces.internal.util.EntityResolver2Wrapper;
import com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper;
import com.sun.org.apache.xerces.internal.util.SAXMessageFormatter;
import com.sun.org.apache.xerces.internal.util.SymbolTable;
import com.sun.org.apache.xerces.internal.xni.XNIException;
import com.sun.org.apache.xerces.internal.xni.grammars.XMLGrammarPool;
import com.sun.org.apache.xerces.internal.xni.parser.XMLConfigurationException;
import com.sun.org.apache.xerces.internal.xni.parser.XMLEntityResolver;
import com.sun.org.apache.xerces.internal.xni.parser.XMLErrorHandler;
import com.sun.org.apache.xerces.internal.xni.parser.XMLInputSource;
import com.sun.org.apache.xerces.internal.xni.parser.XMLParseException;
import com.sun.org.apache.xerces.internal.xni.parser.XMLParserConfiguration;
import org.w3c.dom.Node;
import org.xml.sax.EntityResolver;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;
import org.xml.sax.SAXParseException;
import org.xml.sax.ext.EntityResolver2;
import org.xml.sax.helpers.LocatorImpl;

/**
* This is the main Xerces DOM parser class. It uses the abstract DOM
* parser with a document scanner, a dtd scanner, and a validator, as
* well as a grammar pool.
*
* @author Arnaud Le Hors, IBM
* @author Andy Clark, IBM
*
* @version $Id: DOMParser.java,v 1.2.6.1 2005/09/06 13:06:37 sunithareddy Exp $
*/
public class DOMParser
extends AbstractDOMParser {

//
// Constants
//

// features

/** Feature identifier: EntityResolver2. */
protected static final String USE_ENTITY_RESOLVER2 =
Constants.SAX_FEATURE_PREFIX + Constants.USE_ENTITY_RESOLVER2_FEATURE;

// properties

/** Property identifier: symbol table. */
protected static final String SYMBOL_TABLE =
Constants.XERCES_PROPERTY_PREFIX + Constants.SYMBOL_TABLE_PROPERTY;

/** Property identifier: XML grammar pool. */
protected static final String XMLGRAMMAR_POOL =
Constants.XERCES_PROPERTY_PREFIX+Constants.XMLGRAMMAR_POOL_PROPERTY;

/** Recognized properties. */
private static final String[] RECOGNIZED_PROPERTIES = {
SYMBOL_TABLE,
XMLGRAMMAR_POOL,
};

//
// Data
//

// features

/** Use EntityResolver2. */
protected boolean fUseEntityResolver2 = true;

//
// Constructors
//

/**
* Constructs a DOM parser using the specified parser configuration.
*/
public DOMParser(XMLParserConfiguration config) {
super(config);
} // <init>(XMLParserConfiguration)

/**
* Constructs a DOM parser using the dtd/xml schema parser configuration.
*/
public DOMParser() {
this(null, null);
} // <init>()

/**
* Constructs a DOM parser using the specified symbol table.
*/
public DOMParser(SymbolTable symbolTable) {
this(symbolTable, null);
} // <init>(SymbolTable)


/**
* Constructs a DOM parser using the specified symbol table and
* grammar pool.
*/
public DOMParser(SymbolTable symbolTable, XMLGrammarPool grammarPool) {
super((XMLParserConfiguration)ObjectFactory.createObject(
"com.sun.org.apache.xerces.internal.xni.parser.XMLParserConfiguration",
"com.sun.org.apache.xerces.internal.parsers.XIncludeAwareParserConfiguration"
));

// set properties
fConfiguration.addRecognizedProperties(RECOGNIZED_PROPERTIES);
if (symbolTable != null) {
fConfiguration.setProperty(SYMBOL_TABLE, symbolTable);
}
if (grammarPool != null) {
fConfiguration.setProperty(XMLGRAMMAR_POOL, grammarPool);
}

} // <init>(SymbolTable,XMLGrammarPool)

//
// XMLReader methods
//

/**
* Parses the input source specified by the given system identifier.
* <p>
* This method is equivalent to the following:
* <pre>
* parse(new InputSource(systemId));
* </pre>
*
* @param systemId The system identifier (URI).
*
* @exception org.xml.sax.SAXException Throws exception on SAX error.
* @exception java.io.IOException Throws exception on i/o error.
*/
public void parse(String systemId) throws SAXException, IOException {

// parse document
XMLInputSource source = new XMLInputSource(null, systemId, null);
try {
parse(source);
}

// wrap XNI exceptions as SAX exceptions
catch (XMLParseException e) {
Exception ex = e.getException();
if (ex == null) {
// must be a parser exception; mine it for locator info and throw
// a SAXParseException
LocatorImpl locatorImpl = new LocatorImpl();
locatorImpl.setPublicId(e.getPublicId());
locatorImpl.setSystemId(e.getExpandedSystemId());
locatorImpl.setLineNumber(e.getLineNumber());
locatorImpl.setColumnNumber(e.getColumnNumber());
throw new SAXParseException(e.getMessage(), locatorImpl);
}
if (ex instanceof SAXException) {
// why did we create an XMLParseException?
throw (SAXException)ex;
}
if (ex instanceof IOException) {
throw (IOException)ex;
}
throw new SAXException(ex);
}
catch (XNIException e) {
e.printStackTrace();
Exception ex = e.getException();
if (ex == null) {
throw new SAXException(e.getMessage());
}
if (ex instanceof SAXException) {
throw (SAXException)ex;
}
if (ex instanceof IOException) {
throw (IOException)ex;
}
throw new SAXException(ex);
}

} // parse(String)

[m0317045]

/**
* parse
*
* @param inputSource
*
* @exception org.xml.sax.SAXException
* @exception java.io.IOException
*/
public void parse(InputSource inputSource)
throws SAXException, IOException {

// parse document
try {
XMLInputSource xmlInputSource =
new XMLInputSource(inputSource.getPublicId(),
inputSource.getSystemId(),
null);
xmlInputSource.setByteStream(inputSource.getByteStream());
xmlInputSource.setCharacterStream(inputSource.getCharacterStream());
xmlInputSource.setEncoding(inputSource.getEncoding());
parse(xmlInputSource);
}

// wrap XNI exceptions as SAX exceptions
catch (XMLParseException e) {
Exception ex = e.getException();
if (ex == null) {
// must be a parser exception; mine it for locator info and throw
// a SAXParseException
LocatorImpl locatorImpl = new LocatorImpl();
locatorImpl.setPublicId(e.getPublicId());
locatorImpl.setSystemId(e.getExpandedSystemId());
locatorImpl.setLineNumber(e.getLineNumber());
locatorImpl.setColumnNumber(e.getColumnNumber());
throw new SAXParseException(e.getMessage(), locatorImpl);
}
if (ex instanceof SAXException) {
// why did we create an XMLParseException?
throw (SAXException)ex;
}
if (ex instanceof IOException) {
throw (IOException)ex;
}
throw new SAXException(ex);
}
catch (XNIException e) {
Exception ex = e.getException();
if (ex == null) {
throw new SAXException(e.getMessage());
}
if (ex instanceof SAXException) {
throw (SAXException)ex;
}
if (ex instanceof IOException) {
throw (IOException)ex;
}
throw new SAXException(ex);
}

} // parse(InputSource)

/**
* Sets the resolver used to resolve external entities. The EntityResolver
* interface supports resolution of public and system identifiers.
*
* @param resolver The new entity resolver. Passing a null value will
* uninstall the currently installed resolver.
*/
public void setEntityResolver(EntityResolver resolver) {

try {
XMLEntityResolver xer = (XMLEntityResolver) fConfiguration.getProperty(ENTITY_RESOLVER);
if (fUseEntityResolver2 && resolver instanceof EntityResolver2) {
if (xer instanceof EntityResolver2Wrapper) {
EntityResolver2Wrapper er2w = (EntityResolver2Wrapper) xer;
er2w.setEntityResolver((EntityResolver2) resolver);
}
else {
fConfiguration.setProperty(ENTITY_RESOLVER,
new EntityResolver2Wrapper((EntityResolver2) resolver));
}
}
else {
if (xer instanceof EntityResolverWrapper) {
EntityResolverWrapper erw = (EntityResolverWrapper) xer;
erw.setEntityResolver(resolver);
}
else {
fConfiguration.setProperty(ENTITY_RESOLVER,
new EntityResolverWrapper(resolver));
}
}
}
catch (XMLConfigurationException e) {
// do nothing
}

} // setEntityResolver(EntityResolver)

/**
* Return the current entity resolver.
*
* @return The current entity resolver, or null if none
* has been registered.
* @see #setEntityResolver
*/
public EntityResolver getEntityResolver() {

EntityResolver entityResolver = null;
try {
XMLEntityResolver xmlEntityResolver =
(XMLEntityResolver)fConfiguration.getProperty(ENTITY_RESOLVER);
if (xmlEntityResolver != null) {
if (xmlEntityResolver instanceof EntityResolverWrapper) {
entityResolver =
((EntityResolverWrapper) xmlEntityResolver).getEntityResolver();
}
else if (xmlEntityResolver instanceof EntityResolver2Wrapper) {
entityResolver =
((EntityResolver2Wrapper) xmlEntityResolver).getEntityResolver();
}
}
}
catch (XMLConfigurationException e) {
// do nothing
}
return entityResolver;

} // getEntityResolver():EntityResolver

/**
* Allow an application to register an error event handler.
*
* <p>If the application does not register an error handler, all
* error events reported by the SAX parser will be silently
* ignored; however, normal processing may not continue. It is
* highly recommended that all SAX applications implement an
* error handler to avoid unexpected bugs.</p>
*
* <p>Applications may register a new or different handler in the
* middle of a parse, and the SAX parser must begin using the new
* handler immediately.</p>
*
* @param errorHandler The error handler.
* @exception java.lang.NullPointerException If the handler
* argument is null.
* @see #getErrorHandler
*/
public void setErrorHandler(ErrorHandler errorHandler) {

try {
XMLErrorHandler xeh = (XMLErrorHandler) fConfiguration.getProperty(ERROR_HANDLER);
if (xeh instanceof ErrorHandlerWrapper) {
ErrorHandlerWrapper ehw = (ErrorHandlerWrapper) xeh;
ehw.setErrorHandler(errorHandler);
}
else {
fConfiguration.setProperty(ERROR_HANDLER,
new ErrorHandlerWrapper(errorHandler));
}
}
catch (XMLConfigurationException e) {
// do nothing
}

} // setErrorHandler(ErrorHandler)

[m0317045]

在默认jdk里都有
在你没删的前提下,

[david4034647]

这个包存在于apche服务器中，你把网线拔了你看还能导入吗？明白了吧！

[ts2794]

学习

[youhaodeyi]

难道说在使用这个包的时候还需要启动apache吗？我使了以下不用呀。
如果在默认jdk中都有的话为什么帮助文挡中确没有呢？

[youhaodeyi]

高手帮忙了