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MXP1 is a stable XmlPull parsing engine that is based on ideas from XPP and in particular XPP2 but completely revised and rewritten to take the best advantage of latest JIT JVMs such as Hotspot in JDK 1.4+.

The newest version!
/* -*-             c-basic-offset: 4; indent-tabs-mode: nil; -*-  //------100-columns-wide------>|*/
// for license please see accompanying LICENSE.txt file (available also at http://www.xmlpull.org/)

package org.xmlpull.v1;

import java.io.InputStream;
import java.io.IOException;
import java.io.Reader;

/**
 * XML Pull Parser is an interface that defines parsing functionlity provided
 * in XMLPULL V1 API (visit this website to
 * learn more about API and its implementations).
 *
 * 

There are following different * kinds of parser depending on which features are set:

    *
  • non-validating parser as defined in XML 1.0 spec when * FEATURE_PROCESS_DOCDECL is set to true *
  • validating parser as defined in XML 1.0 spec when * FEATURE_VALIDATION is true (and that implies that FEATURE_PROCESS_DOCDECL is true) *
  • when FEATURE_PROCESS_DOCDECL is false (this is default and * if different value is required necessary must be changed before parsing is started) * then parser behaves like XML 1.0 compliant non-validating parser under condition that * no DOCDECL is present in XML documents * (internal entites can still be defined with defineEntityReplacementText()). * This mode of operation is intened for operation in constrained environments such as J2ME. *
* * *

There are two key methods: next() and nextToken(). While next() provides * access to high level parsing events, nextToken() allows access to lower * level tokens. * *

The current event state of the parser * can be determined by calling the * getEventType() method. * Initially, the parser is in the START_DOCUMENT * state. * *

The method next() advances the parser to the * next event. The int value returned from next determines the current parser * state and is identical to the value returned from following calls to * getEventType (). * *

Th following event types are seen by next()

*
START_TAG
An XML start tag was read. *
TEXT
Text content was read; * the text content can be retreived using the getText() method. * (when in validating mode next() will not report ignorable whitespaces, use nextToken() instead) *
END_TAG
An end tag was read *
END_DOCUMENT
No more events are available *
* *

after first next() or nextToken() (or any other next*() method) * is called user application can obtain * XML version, standalone and encoding from XML declaration * in following ways:

    *
  • version: * getProperty("http://xmlpull.org/v1/doc/properties.html#xmldecl-version") * returns String ("1.0") or null if XMLDecl was not read or if property is not supported *
  • standalone: * getProperty("http://xmlpull.org/v1/doc/features.html#xmldecl-standalone") * returns Boolean: null if there was no standalone declaration * or if property is not supported * otherwise returns Boolean(true) if standalon="yes" and Boolean(false) when standalone="no" *
  • encoding: obtained from getInputEncoding() * null if stream had unknown encoding (not set in setInputStream) * and it was not declared in XMLDecl *
* * A minimal example for using this API may look as follows: *
 * import java.io.IOException;
 * import java.io.StringReader;
 *
 * import org.xmlpull.v1.XmlPullParser;
 * import org.xmlpull.v1.XmlPullParserException.html;
 * import org.xmlpull.v1.XmlPullParserFactory;
 *
 * public class SimpleXmlPullApp
 * {
 *
 *     public static void main (String args[])
 *         throws XmlPullParserException, IOException
 *     {
 *         XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
 *         factory.setNamespaceAware(true);
 *         XmlPullParser xpp = factory.newPullParser();
 *
 *         xpp.setInput( new StringReader ( "<foo>Hello World!</foo>" ) );
 *         int eventType = xpp.getEventType();
 *         while (eventType != XmlPullParser.END_DOCUMENT) {
 *          if(eventType == XmlPullParser.START_DOCUMENT) {
 *              System.out.println("Start document");
 *          } else if(eventType == XmlPullParser.END_DOCUMENT) {
 *              System.out.println("End document");
 *          } else if(eventType == XmlPullParser.START_TAG) {
 *              System.out.println("Start tag "+xpp.getName());
 *          } else if(eventType == XmlPullParser.END_TAG) {
 *              System.out.println("End tag "+xpp.getName());
 *          } else if(eventType == XmlPullParser.TEXT) {
 *              System.out.println("Text "+xpp.getText());
 *          }
 *          eventType = xpp.next();
 *         }
 *     }
 * }
 * 
* *

The above example will generate the following output: *

 * Start document
 * Start tag foo
 * Text Hello World!
 * End tag foo
 * 
* *

For more details on API usage, please refer to the * quick Introduction available at http://www.xmlpull.org * * @see XmlPullParserFactory * @see #defineEntityReplacementText * @see #getName * @see #getNamespace * @see #getText * @see #next * @see #nextToken * @see #setInput * @see #FEATURE_PROCESS_DOCDECL * @see #FEATURE_VALIDATION * @see #START_DOCUMENT * @see #START_TAG * @see #TEXT * @see #END_TAG * @see #END_DOCUMENT * * @author Stefan Haustein * @author Aleksander Slominski */ public interface XmlPullParser { /** This constant represents the default namespace (empty string "") */ String NO_NAMESPACE = ""; // ---------------------------------------------------------------------------- // EVENT TYPES as reported by next() /** * Signalize that parser is at the very beginning of the document * and nothing was read yet. * This event type can only be observed by calling getEvent() * before the first call to next(), nextToken, or nextTag()). * * @see #next * @see #nextToken */ int START_DOCUMENT = 0; /** * Logical end of the xml document. Returned from getEventType, next() * and nextToken() * when the end of the input document has been reached. *

NOTE: calling again * next() or nextToken() * will result in exception being thrown. * * @see #next * @see #nextToken */ int END_DOCUMENT = 1; /** * Returned from getEventType(), * next(), nextToken() when * a start tag was read. * The name of start tag is available from getName(), its namespace and prefix are * available from getNamespace() and getPrefix() * if namespaces are enabled. * See getAttribute* methods to retrieve element attributes. * See getNamespace* methods to retrieve newly declared namespaces. * * @see #next * @see #nextToken * @see #getName * @see #getPrefix * @see #getNamespace * @see #getAttributeCount * @see #getDepth * @see #getNamespaceCount * @see #getNamespace * @see #FEATURE_PROCESS_NAMESPACES */ int START_TAG = 2; /** * Returned from getEventType(), next(), or * nextToken() when an end tag was read. * The name of start tag is available from getName(), its * namespace and prefix are * available from getNamespace() and getPrefix(). * * @see #next * @see #nextToken * @see #getName * @see #getPrefix * @see #getNamespace * @see #FEATURE_PROCESS_NAMESPACES */ int END_TAG = 3; /** * Character data was read and will is available by calling getText(). *

Please note: next() will * accumulate multiple * events into one TEXT event, skipping IGNORABLE_WHITESPACE, * PROCESSING_INSTRUCTION and COMMENT events, * In contrast, nextToken() will stop reading * text when any other event is observed. * Also, when the state was reached by calling next(), the text value will * be normalized, whereas getText() will * return unnormalized content in the case of nextToken(). This allows * an exact roundtrip without chnanging line ends when examining low * level events, whereas for high level applications the text is * normalized apropriately. * * @see #next * @see #nextToken * @see #getText */ int TEXT = 4; // ---------------------------------------------------------------------------- // additional events exposed by lower level nextToken() /** * A CDATA sections was just read; * this token is available only from calls to nextToken(). * A call to next() will accumulate various text events into a single event * of type TEXT. The text contained in the CDATA section is available * by callling getText(). * * @see #nextToken * @see #getText */ int CDSECT = 5; /** * An entity reference was just read; * this token is available from nextToken() * only. The entity name is available by calling getName(). If available, * the replacement text can be obtained by calling getTextt(); otherwise, * the user is responsibile for resolving the entity reference. * This event type is never returned from next(); next() will * accumulate the replacement text and other text * events to a single TEXT event. * * @see #nextToken * @see #getText */ int ENTITY_REF = 6; /** * Ignorable whitespace was just read. * This token is available only from nextToken()). * For non-validating * parsers, this event is only reported by nextToken() when outside * the root element. * Validating parsers may be able to detect ignorable whitespace at * other locations. * The ignorable whitespace string is available by calling getText() * *

NOTE: this is different from calling the * isWhitespace() method, since text content * may be whitespace but not ignorable. * * Ignorable whitespace is skipped by next() automatically; this event * type is never returned from next(). * * @see #nextToken * @see #getText */ int IGNORABLE_WHITESPACE = 7; /** * An XML processing instruction declaration was just read. This * event type is available only via nextToken(). * getText() will return text that is inside the processing instruction. * Calls to next() will skip processing instructions automatically. * @see #nextToken * @see #getText */ int PROCESSING_INSTRUCTION = 8; /** * An XML comment was just read. This event type is this token is * available via nextToken() only; * calls to next() will skip comments automatically. * The content of the comment can be accessed using the getText() * method. * * @see #nextToken * @see #getText */ int COMMENT = 9; /** * An XML document type declaration was just read. This token is * available from nextToken() only. * The unparsed text inside the doctype is available via * the getText() method. * * @see #nextToken * @see #getText */ int DOCDECL = 10; /** * This array can be used to convert the event type integer constants * such as START_TAG or TEXT to * to a string. For example, the value of TYPES[START_TAG] is * the string "START_TAG". * * This array is intended for diagnostic output only. Relying * on the contents of the array may be dangerous since malicous * applications may alter the array, although it is final, due * to limitations of the Java language. */ String [] TYPES = { "START_DOCUMENT", "END_DOCUMENT", "START_TAG", "END_TAG", "TEXT", "CDSECT", "ENTITY_REF", "IGNORABLE_WHITESPACE", "PROCESSING_INSTRUCTION", "COMMENT", "DOCDECL" }; // ---------------------------------------------------------------------------- // namespace related features /** * This feature determines whether the parser processes * namespaces. As for all features, the default value is false. *

NOTE: The value can not be changed during * parsing an must be set before parsing. * * @see #getFeature * @see #setFeature */ String FEATURE_PROCESS_NAMESPACES = "http://xmlpull.org/v1/doc/features.html#process-namespaces"; /** * This feature determines whether namespace attributes are * exposed via the attribute access methods. Like all features, * the default value is false. This feature cannot be changed * during parsing. * * @see #getFeature * @see #setFeature */ String FEATURE_REPORT_NAMESPACE_ATTRIBUTES = "http://xmlpull.org/v1/doc/features.html#report-namespace-prefixes"; /** * This feature determines whether the document declaration * is processed. If set to false, * the DOCDECL event type is reported by nextToken() * and ignored by next(). * * If this featue is activated, then the document declaration * must be processed by the parser. * *

Please note: If the document type declaration * was ignored, entity references may cause exceptions * later in the parsing process. * The default value of this feature is false. It cannot be changed * during parsing. * * @see #getFeature * @see #setFeature */ String FEATURE_PROCESS_DOCDECL = "http://xmlpull.org/v1/doc/features.html#process-docdecl"; /** * If this feature is activated, all validation errors as * defined in the XML 1.0 sepcification are reported. * This implies that FEATURE_PROCESS_DOCDECL is true and both, the * internal and external document type declaration will be processed. *

Please Note: This feature can not be changed * during parsing. The default value is false. * * @see #getFeature * @see #setFeature */ String FEATURE_VALIDATION = "http://xmlpull.org/v1/doc/features.html#validation"; /** * Use this call to change the general behaviour of the parser, * such as namespace processing or doctype declaration handling. * This method must be called before the first call to next or * nextToken. Otherwise, an exception is thrown. *

Example: call setFeature(FEATURE_PROCESS_NAMESPACES, true) in order * to switch on namespace processing. The initial settings correspond * to the properties requested from the XML Pull Parser factory. * If none were requested, all feautures are deactivated by default. * * @exception XmlPullParserException If the feature is not supported or can not be set * @exception IllegalArgumentException If string with the feature name is null */ void setFeature(String name, boolean state) throws XmlPullParserException; /** * Returns the current value of the given feature. *

Please note: unknown features are * always returned as false. * * @param name The name of feature to be retrieved. * @return The value of the feature. * @exception IllegalArgumentException if string the feature name is null */ boolean getFeature(String name); /** * Set the value of a property. * * The property name is any fully-qualified URI. * * @exception XmlPullParserException If the property is not supported or can not be set * @exception IllegalArgumentException If string with the property name is null */ void setProperty(String name, Object value) throws XmlPullParserException; /** * Look up the value of a property. * * The property name is any fully-qualified URI. *

NOTE: unknown properties are always * returned as null. * * @param name The name of property to be retrieved. * @return The value of named property. */ Object getProperty(String name); /** * Set the input source for parser to the given reader and * resets the parser. The event type is set to the initial value * START_DOCUMENT. * Setting the reader to null will just stop parsing and * reset parser state, * allowing the parser to free internal resources * such as parsing buffers. */ void setInput(Reader in) throws XmlPullParserException; /** * Sets the input stream the parser is going to process. * This call resets the parser state and sets the event type * to the initial value START_DOCUMENT. * *

NOTE: If an input encoding string is passed, * it MUST be used. Otherwise, * if inputEncoding is null, the parser SHOULD try to determine * input encoding following XML 1.0 specification (see below). * If encoding detection is supported then following feature * http://xmlpull.org/v1/doc/features.html#detect-encoding * MUST be true amd otherwise it must be false * * @param inputStream contains a raw byte input stream of possibly * unknown encoding (when inputEncoding is null). * * @param inputEncoding if not null it MUST be used as encoding for inputStream */ void setInput(InputStream inputStream, String inputEncoding) throws XmlPullParserException; /** * Returns the input encoding if known, null otherwise. * If setInput(InputStream, inputEncoding) was called with an inputEncoding * value other than null, this value must be returned * from this method. Otherwise, if inputEncoding is null and * the parser suppports the encoding detection feature * (http://xmlpull.org/v1/doc/features.html#detect-encoding), * it must return the detected encoding. * If setInput(Reader) was called, null is returned. * After first call to next if XML declaration was present this method * will return encoding declared. */ String getInputEncoding(); /** * Set new value for entity replacement text as defined in * XML 1.0 Section 4.5 * Construction of Internal Entity Replacement Text. * If FEATURE_PROCESS_DOCDECL or FEATURE_VALIDATION are set, calling this * function will result in an exception -- when processing of DOCDECL is * enabled, there is no need to the entity replacement text manually. * *

The motivation for this function is to allow very small * implementations of XMLPULL that will work in J2ME environments. * Though these implementations may not be able to process the document type * declaration, they still can work with known DTDs by using this function. * *

Please notes: The given value is used literally as replacement text * and it corresponds to declaring entity in DTD that has all special characters * escaped: left angle bracket is replaced with &lt;, ampersnad with &amp; * and so on. * *

Note: The given value is the literal replacement text and must not * contain any other entity reference (if it contains any entity reference * there will be no further replacement). * *

Note: The list of pre-defined entity names will * always contain standard XML entities such as * amp (&amp;), lt (&lt;), gt (&gt;), quot (&quot;), and apos (&apos;). * Those cannot be redefined by this method! * * @see #setInput * @see #FEATURE_PROCESS_DOCDECL * @see #FEATURE_VALIDATION */ void defineEntityReplacementText( String entityName, String replacementText ) throws XmlPullParserException; /** * Returns the numbers of elements in the namespace stack for the given * depth. * If namespaces are not enabled, 0 is returned. * *

NOTE: when parser is on END_TAG then it is allowed to call * this function with getDepth()+1 argument to retrieve position of namespace * prefixes and URIs that were declared on corresponding START_TAG. *

NOTE: to retrieve lsit of namespaces declared in current element:

     *       XmlPullParser pp = ...
     *       int nsStart = pp.getNamespaceCount(pp.getDepth()-1);
     *       int nsEnd = pp.getNamespaceCount(pp.getDepth());
     *       for (int i = nsStart; i < nsEnd; i++) {
     *          String prefix = pp.getNamespacePrefix(i);
     *          String ns = pp.getNamespaceUri(i);
     *           // ...
     *      }
     * 
* * @see #getNamespacePrefix * @see #getNamespaceUri * @see #getNamespace() * @see #getNamespace(String) */ int getNamespaceCount(int depth) throws XmlPullParserException; /** * Returns the namespace prefixe for the given position * in the namespace stack. * Default namespace declaration (xmlns='...') will have null as prefix. * If the given index is out of range, an exception is thrown. *

Please note: when the parser is on an END_TAG, * namespace prefixes that were declared * in the corresponding START_TAG are still accessible * although they are no longer in scope. */ String getNamespacePrefix(int pos) throws XmlPullParserException; /** * Returns the namespace URI for the given position in the * namespace stack * If the position is out of range, an exception is thrown. *

NOTE: when parser is on END_TAG then namespace prefixes that were declared * in corresponding START_TAG are still accessible even though they are not in scope */ String getNamespaceUri(int pos) throws XmlPullParserException; /** * Returns the URI corresponding to the given prefix, * depending on current state of the parser. * *

If the prefix was not declared in the current scope, * null is returned. The default namespace is included * in the namespace table and is available via * getNamespace (null). * *

This method is a convenience method for * *

     *  for (int i = getNamespaceCount(getDepth ())-1; i >= 0; i--) {
     *   if (getNamespacePrefix(i).equals( prefix )) {
     *     return getNamespaceUri(i);
     *   }
     *  }
     *  return null;
     * 
* *

Please note: parser implementations * may provide more efifcient lookup, e.g. using a Hashtable. * The 'xml' prefix is bound to "http://www.w3.org/XML/1998/namespace", as * defined in the * Namespaces in XML * specification. Analogous, the 'xmlns' prefix is resolved to * http://www.w3.org/2000/xmlns/ * * @see #getNamespaceCount * @see #getNamespacePrefix * @see #getNamespaceUri */ String getNamespace (String prefix); // -------------------------------------------------------------------------- // miscellaneous reporting methods /** * Returns the current depth of the element. * Outside the root element, the depth is 0. The * depth is incremented by 1 when a start tag is reached. * The depth is decremented AFTER the end tag * event was observed. * *

     * <!-- outside -->     0
     * <root>                  1
     *   sometext                 1
     *     <foobar>         2
     *     </foobar>        2
     * </root>              1
     * <!-- outside -->     0
     * 
*/ int getDepth(); /** * Returns a short text describing the current parser state, including * the position, a * description of the current event and the data source if known. * This method is especially useful to provide meaningful * error messages and for debugging purposes. */ String getPositionDescription (); /** * Returns the current line number, starting from 1. * When the parser does not know the current line number * or can not determine it, -1 is returned (e.g. for WBXML). * * @return current line number or -1 if unknown. */ int getLineNumber(); /** * Returns the current column number, starting from 0. * When the parser does not know the current column number * or can not determine it, -1 is returned (e.g. for WBXML). * * @return current column number or -1 if unknown. */ int getColumnNumber(); // -------------------------------------------------------------------------- // TEXT related methods /** * Checks whether the current TEXT event contains only whitespace * characters. * For IGNORABLE_WHITESPACE, this is always true. * For TEXT and CDSECT, false is returned when the current event text * contains at least one non-white space character. For any other * event type an exception is thrown. * *

Please note: non-validating parsers are not * able to distinguish whitespace and ignorable whitespace, * except from whitespace outside the root element. Ignorable * whitespace is reported as separate event, which is exposed * via nextToken only. * */ boolean isWhitespace() throws XmlPullParserException; /** * Returns the text content of the current event as String. * The value returned depends on current event type, * for example for TEXT event it is element content * (this is typical case when next() is used). * * See description of nextToken() for detailed description of * possible returned values for different types of events. * *

NOTE: in case of ENTITY_REF, this method returns * the entity replacement text (or null if not available). This is * the only case where * getText() and getTextCharacters() return different values. * * @see #getEventType * @see #next * @see #nextToken */ String getText (); /** * Returns the buffer that contains the text of the current event, * as well as the start offset and length relevant for the current * event. See getText(), next() and nextToken() for description of possible returned values. * *

Please note: this buffer must not * be modified and its content MAY change after a call to * next() or nextToken(). This method will always return the * same value as getText(), except for ENTITY_REF. In the case * of ENTITY ref, getText() returns the replacement text and * this method returns the actual input buffer containing the * entity name. * If getText() returns null, this method returns null as well and * the values returned in the holder array MUST be -1 (both start * and length). * * @see #getText * @see #next * @see #nextToken * * @param holderForStartAndLength Must hold an 2-element int array * into which the start offset and length values will be written. * @return char buffer that contains the text of the current event * (null if the current event has no text associated). */ char[] getTextCharacters(int [] holderForStartAndLength); // -------------------------------------------------------------------------- // START_TAG / END_TAG shared methods /** * Returns the namespace URI of the current element. * The default namespace is represented * as empty string. * If namespaces are not enabled, an empty String ("") is always returned. * The current event must be START_TAG or END_TAG; otherwise, * null is returned. */ String getNamespace (); /** * For START_TAG or END_TAG events, the (local) name of the current * element is returned when namespaces are enabled. When namespace * processing is disabled, the raw name is returned. * For ENTITY_REF events, the entity name is returned. * If the current event is not START_TAG, END_TAG, or ENTITY_REF, * null is returned. *

Please note: To reconstruct the raw element name * when namespaces are enabled and the prefix is not null, * you will need to add the prefix and a colon to localName.. * */ String getName(); /** * Returns the prefix of the current element. * If the element is in the default namespace (has no prefix), * null is returned. * If namespaces are not enabled, or the current event * is not START_TAG or END_TAG, null is returned. */ String getPrefix(); /** * Returns true if the current event is START_TAG and the tag * is degenerated * (e.g. <foobar/>). *

NOTE: if the parser is not on START_TAG, an exception * will be thrown. */ boolean isEmptyElementTag() throws XmlPullParserException; // -------------------------------------------------------------------------- // START_TAG Attributes retrieval methods /** * Returns the number of attributes of the current start tag, or * -1 if the current event type is not START_TAG * * @see #getAttributeNamespace * @see #getAttributeName * @see #getAttributePrefix * @see #getAttributeValue */ int getAttributeCount(); /** * Returns the namespace URI of the attribute * with the given index (starts from 0). * Returns an empty string ("") if namespaces are not enabled * or the attribute has no namespace. * Throws an IndexOutOfBoundsException if the index is out of range * or the current event type is not START_TAG. * *

NOTE: if FEATURE_REPORT_NAMESPACE_ATTRIBUTES is set * then namespace attributes (xmlns:ns='...') must be reported * with namespace * http://www.w3.org/2000/xmlns/ * (visit this URL for description!). * The default namespace attribute (xmlns="...") will be reported with empty namespace. *

NOTE:The xml prefix is bound as defined in * Namespaces in XML * specification to "http://www.w3.org/XML/1998/namespace". * * @param zero based index of attribute * @return attribute namespace, * empty string ("") is returned if namesapces processing is not enabled or * namespaces processing is enabled but attribute has no namespace (it has no prefix). */ String getAttributeNamespace (int index); /** * Returns the local name of the specified attribute * if namespaces are enabled or just attribute name if namespaces are disabled. * Throws an IndexOutOfBoundsException if the index is out of range * or current event type is not START_TAG. * * @param zero based index of attribute * @return attribute name (null is never returned) */ String getAttributeName (int index); /** * Returns the prefix of the specified attribute * Returns null if the element has no prefix. * If namespaces are disabled it will always return null. * Throws an IndexOutOfBoundsException if the index is out of range * or current event type is not START_TAG. * * @param zero based index of attribute * @return attribute prefix or null if namespaces processing is not enabled. */ String getAttributePrefix(int index); /** * Returns the type of the specified attribute * If parser is non-validating it MUST return CDATA. * * @param zero based index of attribute * @return attribute type (null is never returned) */ String getAttributeType(int index); /** * Returns if the specified attribute was not in input was declared in XML. * If parser is non-validating it MUST always return false. * This information is part of XML infoset: * * @param zero based index of attribute * @return false if attribute was in input */ boolean isAttributeDefault(int index); /** * Returns the given attributes value. * Throws an IndexOutOfBoundsException if the index is out of range * or current event type is not START_TAG. * *

NOTE: attribute value must be normalized * (including entity replacement text if PROCESS_DOCDECL is false) as described in * XML 1.0 section * 3.3.3 Attribute-Value Normalization * * @see #defineEntityReplacementText * * @param zero based index of attribute * @return value of attribute (null is never returned) */ String getAttributeValue(int index); /** * Returns the attributes value identified by namespace URI and namespace localName. * If namespaces are disabled namespace must be null. * If current event type is not START_TAG then IndexOutOfBoundsException will be thrown. * *

NOTE: attribute value must be normalized * (including entity replacement text if PROCESS_DOCDECL is false) as described in * XML 1.0 section * 3.3.3 Attribute-Value Normalization * * @see #defineEntityReplacementText * * @param namespace Namespace of the attribute if namespaces are enabled otherwise must be null * @param name If namespaces enabled local name of attribute otherwise just attribute name * @return value of attribute or null if attribute with given name does not exist */ String getAttributeValue(String namespace, String name); // -------------------------------------------------------------------------- // actual parsing methods /** * Returns the type of the current event (START_TAG, END_TAG, TEXT, etc.) * * @see #next() * @see #nextToken() */ int getEventType() throws XmlPullParserException; /** * Get next parsing event - element content wil be coalesced and only one * TEXT event must be returned for whole element content * (comments and processing instructions will be ignored and emtity references * must be expanded or exception mus be thrown if entity reerence can not be exapnded). * If element content is empty (content is "") then no TEXT event will be reported. * *

NOTE: empty element (such as <tag/>) will be reported * with two separate events: START_TAG, END_TAG - it must be so to preserve * parsing equivalency of empty element to <tag></tag>. * (see isEmptyElementTag ()) * * @see #isEmptyElementTag * @see #START_TAG * @see #TEXT * @see #END_TAG * @see #END_DOCUMENT */ int next() throws XmlPullParserException, IOException; /** * This method works similarly to next() but will expose * additional event types (COMMENT, CDSECT, DOCDECL, ENTITY_REF, PROCESSING_INSTRUCTION, or * IGNORABLE_WHITESPACE) if they are available in input. * *

If special feature * FEATURE_XML_ROUNDTRIP * (identified by URI: http://xmlpull.org/v1/doc/features.html#xml-roundtrip) * is enabled it is possible to do XML document round trip ie. reproduce * exectly on output the XML input using getText(): * returned content is always unnormalized (exactly as in input). * Otherwise returned content is end-of-line normalized as described * XML 1.0 End-of-Line Handling * and. Also when this feature is enabled exact content of START_TAG, END_TAG, * DOCDECL and PROCESSING_INSTRUCTION is available. * *

Here is the list of tokens that can be returned from nextToken() * and what getText() and getTextCharacters() returns:

*
START_DOCUMENT
null *
END_DOCUMENT
null *
START_TAG
null unless FEATURE_XML_ROUNDTRIP * enabled and then returns XML tag, ex: <tag attr='val'> *
END_TAG
null unless FEATURE_XML_ROUNDTRIP * id enabled and then returns XML tag, ex: </tag> *
TEXT
return element content. *
Note: that element content may be delivered in multiple consecutive TEXT events. *
IGNORABLE_WHITESPACE
return characters that are determined to be ignorable white * space. If the FEATURE_XML_ROUNDTRIP is enabled all whitespace content outside root * element will always reported as IGNORABLE_WHITESPACE otherise rteporting is optional. *
Note: that element content may be delevered in multiple consecutive IGNORABLE_WHITESPACE events. *
CDSECT
* return text inside CDATA * (ex. 'fo<o' from <!CDATA[fo<o]]>) *
PROCESSING_INSTRUCTION
* if FEATURE_XML_ROUNDTRIP is true * return exact PI content ex: 'pi foo' from <?pi foo?> * otherwise it may be exact PI content or concatenation of PI target, * space and data so for example for * <?target data?> string "target data" may * be returned if FEATURE_XML_ROUNDTRIP is false. *
COMMENT
return comment content ex. 'foo bar' from <!--foo bar--> *
ENTITY_REF
getText() MUST return entity replacement text if PROCESS_DOCDECL is false * otherwise getText() MAY return null, * additionally getTextCharacters() MUST return entity name * (for example 'entity_name' for &entity_name;). *
NOTE: this is the only place where value returned from getText() and * getTextCharacters() are different *
NOTE: it is user responsibility to resolve entity reference * if PROCESS_DOCDECL is false and there is no entity replacement text set in * defineEntityReplacementText() method (getText() will be null) *
NOTE: character entities (ex. &#32;) and standard entities such as * &amp; &lt; &gt; &quot; &apos; are reported as well * and are not reported as TEXT tokens but as ENTITY_REF tokens! * This requirement is added to allow to do roundtrip of XML documents! *
DOCDECL
* if FEATURE_XML_ROUNDTRIP is true or PROCESS_DOCDECL is false * then return what is inside of DOCDECL for example it returns:
     * " titlepage SYSTEM "http://www.foo.bar/dtds/typo.dtd"
     * [<!ENTITY % active.links "INCLUDE">]"
*

for input document that contained:

     * <!DOCTYPE titlepage SYSTEM "http://www.foo.bar/dtds/typo.dtd"
     * [<!ENTITY % active.links "INCLUDE">]>
* otherwise if FEATURE_XML_ROUNDTRIP is false and PROCESS_DOCDECL is true * then what is returned is undefined (it may be even null) *
*
* *

NOTE: there is no gurantee that there will only one TEXT or * IGNORABLE_WHITESPACE event from nextToken() as parser may chose to deliver element content in * multiple tokens (dividing element content into chunks) * *

NOTE: whether returned text of token is end-of-line normalized * is depending on FEATURE_XML_ROUNDTRIP. * *

NOTE: XMLDecl (<?xml ...?>) is not reported but its content * is available through optional properties (see class description above). * * @see #next * @see #START_TAG * @see #TEXT * @see #END_TAG * @see #END_DOCUMENT * @see #COMMENT * @see #DOCDECL * @see #PROCESSING_INSTRUCTION * @see #ENTITY_REF * @see #IGNORABLE_WHITESPACE */ int nextToken() throws XmlPullParserException, IOException; //----------------------------------------------------------------------------- // utility methods to mak XML parsing easier ... /** * Test if the current event is of the given type and if the * namespace and name do match. null will match any namespace * and any name. If the test is not passed, an exception is * thrown. The exception text indicates the parser position, * the expected event and the current event that is not meeting the * requirement. * *

Essentially it does this *

     *  if (type != getEventType()
     *  || (namespace != null &&  !namespace.equals( getNamespace () ) )
     *  || (name != null &&  !name.equals( getName() ) ) )
     *     throw new XmlPullParserException( "expected "+ TYPES[ type ]+getPositionDescription());
     * 
*/ void require(int type, String namespace, String name) throws XmlPullParserException, IOException; /** * If current event is START_TAG then if next element is TEXT then element content is returned * or if next event is END_TAG then empty string is returned, otherwise exception is thrown. * After calling this function successfully parser will be positioned on END_TAG. * *

The motivation for this function is to allow to parse consistently both * empty elements and elements that has non empty content, for example for input:

    *
  1. <tag>foo</tag> *
  2. <tag></tag> (which is equivalent to <tag/> * both input can be parsed with the same code: *
         *   p.nextTag()
         *   p.requireEvent(p.START_TAG, "", "tag");
         *   String content = p.nextText();
         *   p.requireEvent(p.END_TAG, "", "tag");
         * 
    * This function together with nextTag make it very easy to parse XML that has * no mixed content. * * *

    Essentially it does this *

         *  if(getEventType() != START_TAG) {
         *     throw new XmlPullParserException(
         *       "parser must be on START_TAG to read next text", this, null);
         *  }
         *  int eventType = next();
         *  if(eventType == TEXT) {
         *     String result = getText();
         *     eventType = next();
         *     if(eventType != END_TAG) {
         *       throw new XmlPullParserException(
         *          "event TEXT it must be immediately followed by END_TAG", this, null);
         *      }
         *      return result;
         *  } else if(eventType == END_TAG) {
         *     return "";
         *  } else {
         *     throw new XmlPullParserException(
         *       "parser must be on START_TAG or TEXT to read text", this, null);
         *  }
         * 
    */ String nextText() throws XmlPullParserException, IOException; /** * Call next() and return event if it is START_TAG or END_TAG * otherwise throw an exception. * It will skip whitespace TEXT before actual tag if any. * *

    essentially it does this *

         *   int eventType = next();
         *   if(eventType == TEXT &&  isWhitespace()) {   // skip whitespace
         *      eventType = next();
         *   }
         *   if (eventType != START_TAG &&  eventType != END_TAG) {
         *      throw new XmlPullParserException("expected start or end tag", this, null);
         *   }
         *   return eventType;
         * 
    */ int nextTag() throws XmlPullParserException, IOException; // /** // * Skip sub tree on which the parser is currently positioned on. // *
    NOTE: parser must be on START_TAG and when function returns // * parser will be positioned on matching END_TAG // * // * This method is typically optimized by parser but the its logic should follow this: // * // * require(XmlPullParser.START_TAG, null, null); // * int level = 1; // * while(level > 0) { // * int eventType = next(); // * if(eventType == XmlPullParser.END_TAG) { // * --level; // * } else if(eventType == XmlPullParser.START_TAG) { // * ++level; // * } // * } // * // */ // public void skipSubTree() throws XmlPullParserException, IOException; }




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