cadi/core/src/main/java/org/onap/aaf/cadi/wsse/Match.java

   1 /**
   2  * ============LICENSE_START====================================================
   3  * org.onap.aaf
   4  * ===========================================================================
   5  * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
   6  * ===========================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END====================================================
  19  *
  20  */
  21
  22 package org.onap.aaf.cadi.wsse;
  23
  24 import javax.xml.namespace.QName;
  25 import javax.xml.stream.XMLStreamException;
  26 import javax.xml.stream.events.XMLEvent;
  27
  28 /**
  29  * Match Class allows you to build an automatic Tree of StAX (or StAX like)
  30  * Objects for frequent use.
  31  *
  32  * OBJECT is a type which you which to do some end Actions on, similar to a Visitor pattern, see Action
  33  *
  34  * Note: We have implemented with XReader and XEvent, rather than StAX for performance reasons.
  35  *
  36  * @see Action
  37  * @see Match
  38  * @see XEvent
  39  * @see XReader
  40  *
  41  * @author Jonathan
  42  *
  43  * @param <OUTPUT>
  44  */
  45 //@SuppressWarnings("restriction")
  46 public class Match<OUTPUT> {
  47         private QName qname;
  48         private Match<OUTPUT>[] next;
  49         private Match<OUTPUT> prev;
  50         private Action<OUTPUT> action = null;
  51         private boolean stopAfter;
  52         private boolean exclusive;
  53
  54
  55         @SafeVarargs
  56         public Match(String ns, String name, Match<OUTPUT> ... next) {
  57                 this.qname = new QName(ns,name);
  58                 this.next = next;
  59                 stopAfter = exclusive = false;
  60                 for(Match<OUTPUT> m : next) { // add the possible tags to look for
  61                         if(!m.stopAfter)m.prev = this;
  62                 }
  63         }
  64
  65         public Match<OUTPUT> onMatch(OUTPUT output, XReader reader) throws XMLStreamException {
  66                 while(reader.hasNext()) {
  67                         XEvent event = reader.nextEvent();
  68                         switch(event.getEventType()) {
  69                                 case XMLEvent.START_ELEMENT:
  70                                         QName e_qname = event.asStartElement().getName();
  71                                         //System.out.println("Start - " + e_qname);
  72                                         boolean match = false;
  73                                         for(Match<OUTPUT> m : next) {
  74                                                 if(e_qname.equals(m.qname)) {
  75                                                         match=true;
  76                                                         if(m.onMatch(output, reader)==null) {
  77                                                                 return null; // short circuit Parsing
  78                                                         }
  79                                                         break;
  80                                                 }
  81                                         }
  82                                         if(exclusive && !match) // When Tag MUST be present, i.e. the Root Tag, versus info we're not interested in
  83                                                 return null;
  84                                         break;
  85                                 case XMLEvent.CHARACTERS:
  86                                         //System.out.println("Data - " +event.asCharacters().getData());
  87                                         if(action!=null) {
  88                                                 if(!action.content(output,event.asCharacters().getData())) {
  89                                                         return null;
  90                                                 }
  91                                         }
  92                                         break;
  93                                 case XMLEvent.END_ELEMENT:
  94                                         //System.out.println("End - " + event.asEndElement().getName());
  95                                         if(event.asEndElement().getName().equals(qname)) {
  96                                                 return prev;
  97                                         }
  98                                         break;
  99                                 case XMLEvent.END_DOCUMENT:
 100                                         return null; // Exit Chain
 101                         }
 102                 }
 103                 return this;
 104         }
 105
 106         /**
 107          * When this Matched Tag has completed, Stop parsing and end
 108          * @return
 109          */
 110         public Match<OUTPUT> stopAfter() {
 111                 stopAfter = true;
 112                 return this;
 113         }
 114
 115         /**
 116          * Mark that this Object MUST be matched at this level or stop parsing and end
 117          *
 118          * @param action
 119          * @return
 120          */
 121         public Match<OUTPUT> exclusive() {
 122                 exclusive = true;
 123                 return this;
 124         }
 125
 126         public Match<OUTPUT> set(Action<OUTPUT> action) {
 127                 this.action = action;
 128                 return this;
 129         }
 130 }