|
1 package com.thoughtworks.xstream.io.xml;
2
3 import com.thoughtworks.xstream.converters.ErrorWriter;
4 import com.thoughtworks.xstream.core.util.IntQueue;
5 import com.thoughtworks.xstream.core.util.StringStack;
6 import com.thoughtworks.xstream.io.HierarchicalStreamReader;
7 import com.thoughtworks.xstream.io.StreamException;
8 import org.xmlpull.mxp1.MXParser;
9 import org.xmlpull.v1.XmlPullParser;
10 import org.xmlpull.v1.XmlPullParserException;
11
12 import java.io.BufferedReader  ;
13 import java.io.IOException ;
14 import java.io.Reader ;
15
16 public class XppReader implements HierarchicalStreamReader {
17
18 private final XmlPullParser parser;
19 private final StringStack elementStack = new StringStack(16);
20 private final IntQueue lookaheadQueue = new IntQueue(4);
21
22 public XppReader(Reader reader) {
23 try {
24 parser = createParser();
25 parser.setInput(new BufferedReader (reader));
26 moveDown();
27 } catch (XmlPullParserException e) {
28 throw new StreamException(e);
29 }
30 }
31
32 protected XmlPullParser createParser() {
33 return new MXParser();
36 }
37
38 public boolean hasMoreChildren() {
39 while (true) {
40 switch (lookahead()) {
41 case XmlPullParser.START_TAG:
42 return true;
43 case XmlPullParser.END_TAG:
44 case XmlPullParser.END_DOCUMENT:
45 return false;
46 default:
47 continue;
48 }
49 }
50 }
51
52 private int lookahead() {
53 try {
54 int event = parser.next();
55 lookaheadQueue.write(event);
56 return event;
57 } catch (XmlPullParserException e) {
58 throw new StreamException(e);
59 } catch (IOException e) {
60 throw new StreamException(e);
61 }
62 }
63
64 private int next() {
65 if (!lookaheadQueue.isEmpty()) {
66 return lookaheadQueue.read();
67 } else {
68 try {
69 return parser.next();
70 } catch (XmlPullParserException e) {
71 throw new StreamException(e);
72 } catch (IOException e) {
73 throw new StreamException(e);
74 }
75 }
76 }
77
78 public void moveDown() {
79 int currentDepth = elementStack.size();
80 while (elementStack.size() <= currentDepth) {
81 read();
82 if (elementStack.size() < currentDepth) {
83 throw new RuntimeException (); }
85 }
86 }
87
88 public void moveUp() {
89 int currentDepth = elementStack.size();
90 while (elementStack.size() >= currentDepth) {
91 read();
92 }
93 }
94
95 public String getNodeName() {
96 return elementStack.peek();
97 }
98
99 public String getValue() {
100 if (lookahead() == XmlPullParser.TEXT) {
105 String text = parser.getText();
106 return text == null ? "" : text;
107 } else {
108 return "";
109 }
110 }
111
112 public String getAttribute(String name) {
113 return parser.getAttributeValue(null, name);
114 }
115
116 public Object peekUnderlyingNode() {
117 throw new UnsupportedOperationException ();
118 }
119
120 private void read() {
121 switch (next()) {
122 case XmlPullParser.START_TAG:
123 elementStack.push(parser.getName());
124 break;
125 case XmlPullParser.END_TAG:
126 case XmlPullParser.END_DOCUMENT:
127 elementStack.pop();
128 break;
129 }
130 }
131
132 public void appendErrors(ErrorWriter errorWriter) {
133 errorWriter.add("line number", String.valueOf(parser.getLineNumber()));
134 }
135 } |
Popular Tags |
Java API By Example, From Geeks To Geeks.