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1 package com.thoughtworks.xstream.io.xml;
2
3 import com.thoughtworks.xstream.core.util.FastStack;
4 import com.thoughtworks.xstream.io.AttributeNameIterator;
5 import com.thoughtworks.xstream.io.HierarchicalStreamReader;
6
7 import java.util.Iterator  ;
8
9
16 public abstract class AbstractPullReader implements HierarchicalStreamReader {
17
18 protected static final int START_NODE = 1;
19 protected static final int END_NODE = 2;
20 protected static final int TEXT = 3;
21 protected static final int COMMENT = 4;
22 protected static final int OTHER = 0;
23
24 private final FastStack elementStack = new FastStack(16);
25
26 private final FastStack lookahead = new FastStack(4);
27 private final FastStack lookback = new FastStack(4);
28 private boolean marked;
29
30 private static class Event {
31 int type;
32 String value;
33 }
34
35
44 protected abstract int pullNextEvent();
45
46
49 protected abstract String pullElementName();
50
51
54 protected abstract String pullText();
55
56 public boolean hasMoreChildren() {
57 mark();
58 while (true) {
59 switch (readEvent().type) {
60 case START_NODE:
61 reset();
62 return true;
63 case END_NODE:
64 reset();
65 return false;
66 default:
67 continue;
68 }
69 }
70 }
71
72 public void moveDown() {
73 int currentDepth = elementStack.size();
74 while (elementStack.size() <= currentDepth) {
75 move();
76 if (elementStack.size() < currentDepth) {
77 throw new RuntimeException (); }
79 }
80 }
81
82 public void moveUp() {
83 int currentDepth = elementStack.size();
84 while (elementStack.size() >= currentDepth) {
85 move();
86 }
87 }
88
89 private void move() {
90 switch (readEvent().type) {
91 case START_NODE:
92 elementStack.push(pullElementName());
93 break;
94 case END_NODE:
95 elementStack.pop();
96 break;
97 }
98 }
99
100 private Event readEvent() {
101 if (marked) {
102 if (lookback.hasStuff()) {
103 return (Event) lookahead.push(lookback.pop());
104 } else {
105 return (Event) lookahead.push(readRealEvent());
106 }
107 } else {
108 if (lookback.hasStuff()) {
109 return (Event) lookback.pop();
110 } else {
111 return readRealEvent();
112 }
113 }
114 }
115
116 private Event readRealEvent() {
117 Event event = new Event();
118 event.type = pullNextEvent();
119 if (event.type == TEXT) {
120 event.value = pullText();
121 } else if (event.type == START_NODE) {
122 event.value = pullElementName();
123 }
124 return event;
125 }
126
127 public void mark() {
128 marked = true;
129 }
130
131 public void reset() {
132 while(lookahead.hasStuff()) {
133 lookback.push(lookahead.pop());
134 }
135 marked = false;
136 }
137
138 public String getValue() {
139
142 String last = null;
145 StringBuffer buffer = null;
146
147 mark();
148 Event event = readEvent();
149 while (true) {
150 if (event.type == TEXT) {
151 String text = event.value;
152 if (text != null && text.length() > 0) {
153 if (last == null) {
154 last = text;
155 } else {
156 if (buffer == null) {
157 buffer = new StringBuffer (last);
158 }
159 buffer.append(text);
160 }
161 }
162 } else if (event.type != COMMENT) {
163 break;
164 }
165 event = readEvent();
166 }
167 reset();
168 if (buffer != null) {
169 return buffer.toString();
170 } else {
171 return (last == null) ? "" : last;
172 }
173 }
174
175 public Iterator getAttributeNames() {
176 return new AttributeNameIterator(this);
177 }
178
179 public String getNodeName() {
180 return (String ) elementStack.peek();
181 }
182
183 public Object peekUnderlyingNode() {
184 throw new UnsupportedOperationException ();
185 }
186
187 public HierarchicalStreamReader underlyingReader() {
188 return this;
189 }
190
191 }
192 |
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