1/**
2 * Copyright (c) 2008, http://www.snakeyaml.org
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16package org.yaml.snakeyaml.nodes;
17
18import java.math.BigDecimal;
19import java.math.BigInteger;
20import java.net.URI;
21import java.sql.Timestamp;
22import java.util.Date;
23import java.util.HashMap;
24import java.util.HashSet;
25import java.util.Map;
26import java.util.Set;
27
28import org.yaml.snakeyaml.error.YAMLException;
29import org.yaml.snakeyaml.util.UriEncoder;
30
31public final class Tag implements Comparable<Tag> {
32    public static final String PREFIX = "tag:yaml.org,2002:";
33    public static final Tag YAML = new Tag(PREFIX + "yaml");
34    public static final Tag MERGE = new Tag(PREFIX + "merge");
35    public static final Tag SET = new Tag(PREFIX + "set");
36    public static final Tag PAIRS = new Tag(PREFIX + "pairs");
37    public static final Tag OMAP = new Tag(PREFIX + "omap");
38    public static final Tag BINARY = new Tag(PREFIX + "binary");
39    public static final Tag INT = new Tag(PREFIX + "int");
40    public static final Tag FLOAT = new Tag(PREFIX + "float");
41    public static final Tag TIMESTAMP = new Tag(PREFIX + "timestamp");
42    public static final Tag BOOL = new Tag(PREFIX + "bool");
43    public static final Tag NULL = new Tag(PREFIX + "null");
44    public static final Tag STR = new Tag(PREFIX + "str");
45    public static final Tag SEQ = new Tag(PREFIX + "seq");
46    public static final Tag MAP = new Tag(PREFIX + "map");
47    public static final Map<Tag, Set<Class<?>>> COMPATIBILITY_MAP;
48    static {
49        COMPATIBILITY_MAP = new HashMap<Tag, Set<Class<?>>>();
50        Set<Class<?>> floatSet = new HashSet<Class<?>>();
51        floatSet.add(Double.class);
52        floatSet.add(Float.class);
53        floatSet.add(BigDecimal.class);
54        COMPATIBILITY_MAP.put(FLOAT, floatSet);
55        //
56        Set<Class<?>> intSet = new HashSet<Class<?>>();
57        intSet.add(Integer.class);
58        intSet.add(Long.class);
59        intSet.add(BigInteger.class);
60        COMPATIBILITY_MAP.put(INT, intSet);
61        //
62        Set<Class<?>> timestampSet = new HashSet<Class<?>>();
63        timestampSet.add(Date.class);
64        timestampSet.add(java.sql.Date.class);
65        timestampSet.add(Timestamp.class);
66        COMPATIBILITY_MAP.put(TIMESTAMP, timestampSet);
67    }
68
69    private final String value;
70    private boolean secondary = false; // see http://www.yaml.org/refcard.html
71
72    public Tag(String tag) {
73        if (tag == null) {
74            throw new NullPointerException("Tag must be provided.");
75        } else if (tag.length() == 0) {
76            throw new IllegalArgumentException("Tag must not be empty.");
77        } else if (tag.trim().length() != tag.length()) {
78            throw new IllegalArgumentException("Tag must not contain leading or trailing spaces.");
79        }
80        this.value = UriEncoder.encode(tag);
81        this.secondary = !tag.startsWith(PREFIX);
82    }
83
84    public Tag(Class<? extends Object> clazz) {
85        if (clazz == null) {
86            throw new NullPointerException("Class for tag must be provided.");
87        }
88        this.value = Tag.PREFIX + UriEncoder.encode(clazz.getName());
89    }
90
91    //TODO to be removed ?
92    public Tag(URI uri) {
93        if (uri == null) {
94            throw new NullPointerException("URI for tag must be provided.");
95        }
96        this.value = uri.toASCIIString();
97    }
98
99    public boolean isSecondary() {
100        return secondary;
101    }
102
103    public String getValue() {
104        return value;
105    }
106
107    public boolean startsWith(String prefix) {
108        return value.startsWith(prefix);
109    }
110
111    public String getClassName() {
112        if (!value.startsWith(Tag.PREFIX)) {
113            throw new YAMLException("Invalid tag: " + value);
114        }
115        return UriEncoder.decode(value.substring(Tag.PREFIX.length()));
116    }
117
118    public int getLength() {
119        return value.length();
120    }
121
122    @Override
123    public String toString() {
124        return value;
125    }
126
127    @Override
128    public boolean equals(Object obj) {
129        if (obj instanceof Tag) {
130            return value.equals(((Tag) obj).getValue());
131        } else
132            return false;
133    }
134
135    @Override
136    public int hashCode() {
137        return value.hashCode();
138    }
139
140    /**
141     * Java has more then 1 class compatible with a language-independent tag
142     * (!!int, !!float, !!timestamp etc)
143     *
144     * @param clazz
145     *            - Class to check compatibility
146     * @return true when the Class can be represented by this
147     *         language-independent tag
148     */
149    public boolean isCompatible(Class<?> clazz) {
150        Set<Class<?>> set = COMPATIBILITY_MAP.get(this);
151        if (set != null) {
152            return set.contains(clazz);
153        } else {
154            return false;
155        }
156    }
157
158    /**
159     * Check whether this tag matches the global tag for the Class
160     *
161     * @param clazz
162     *            - Class to check
163     * @return true when the this tag can be used as a global tag for the Class
164     */
165    public boolean matches(Class<? extends Object> clazz) {
166        return value.equals(Tag.PREFIX + clazz.getName());
167    }
168
169    public int compareTo(Tag o) {
170        return value.compareTo(o.getValue());
171    }
172}
173