1 /* 2 * Copyright (C) 2006 The Android Open Source Project 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 */ 16 17 package android.content; 18 19 import android.net.Uri; 20 21 import java.util.ArrayList; 22 import java.util.List; 23 import java.util.regex.Pattern; 24 25 /** 26 Utility class to aid in matching URIs in content providers. 27 28 <p>To use this class, build up a tree of <code>UriMatcher</code> objects. 29 For example: 30 <pre> 31 private static final int PEOPLE = 1; 32 private static final int PEOPLE_ID = 2; 33 private static final int PEOPLE_PHONES = 3; 34 private static final int PEOPLE_PHONES_ID = 4; 35 private static final int PEOPLE_CONTACTMETHODS = 7; 36 private static final int PEOPLE_CONTACTMETHODS_ID = 8; 37 38 private static final int DELETED_PEOPLE = 20; 39 40 private static final int PHONES = 9; 41 private static final int PHONES_ID = 10; 42 private static final int PHONES_FILTER = 14; 43 44 private static final int CONTACTMETHODS = 18; 45 private static final int CONTACTMETHODS_ID = 19; 46 47 private static final int CALLS = 11; 48 private static final int CALLS_ID = 12; 49 private static final int CALLS_FILTER = 15; 50 51 private static final UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH); 52 53 static 54 { 55 sURIMatcher.addURI("contacts", "people", PEOPLE); 56 sURIMatcher.addURI("contacts", "people/#", PEOPLE_ID); 57 sURIMatcher.addURI("contacts", "people/#/phones", PEOPLE_PHONES); 58 sURIMatcher.addURI("contacts", "people/#/phones/#", PEOPLE_PHONES_ID); 59 sURIMatcher.addURI("contacts", "people/#/contact_methods", PEOPLE_CONTACTMETHODS); 60 sURIMatcher.addURI("contacts", "people/#/contact_methods/#", PEOPLE_CONTACTMETHODS_ID); 61 sURIMatcher.addURI("contacts", "deleted_people", DELETED_PEOPLE); 62 sURIMatcher.addURI("contacts", "phones", PHONES); 63 sURIMatcher.addURI("contacts", "phones/filter/*", PHONES_FILTER); 64 sURIMatcher.addURI("contacts", "phones/#", PHONES_ID); 65 sURIMatcher.addURI("contacts", "contact_methods", CONTACTMETHODS); 66 sURIMatcher.addURI("contacts", "contact_methods/#", CONTACTMETHODS_ID); 67 sURIMatcher.addURI("call_log", "calls", CALLS); 68 sURIMatcher.addURI("call_log", "calls/filter/*", CALLS_FILTER); 69 sURIMatcher.addURI("call_log", "calls/#", CALLS_ID); 70 } 71 </pre> 72 <p>Starting from API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR2}, paths can start 73 with a leading slash. For example: 74 <pre> 75 sURIMatcher.addURI("contacts", "/people", PEOPLE); 76 </pre> 77 <p>Then when you need to match against a URI, call {@link #match}, providing 78 the URL that you have been given. You can use the result to build a query, 79 return a type, insert or delete a row, or whatever you need, without duplicating 80 all of the if-else logic that you would otherwise need. For example: 81 <pre> 82 public String getType(Uri url) 83 { 84 int match = sURIMatcher.match(url); 85 switch (match) 86 { 87 case PEOPLE: 88 return "vnd.android.cursor.dir/person"; 89 case PEOPLE_ID: 90 return "vnd.android.cursor.item/person"; 91 ... snip ... 92 return "vnd.android.cursor.dir/snail-mail"; 93 case PEOPLE_ADDRESS_ID: 94 return "vnd.android.cursor.item/snail-mail"; 95 default: 96 return null; 97 } 98 } 99 </pre> 100 instead of: 101 <pre> 102 public String getType(Uri url) 103 { 104 List<String> pathSegments = url.getPathSegments(); 105 if (pathSegments.size() >= 2) { 106 if ("people".equals(pathSegments.get(1))) { 107 if (pathSegments.size() == 2) { 108 return "vnd.android.cursor.dir/person"; 109 } else if (pathSegments.size() == 3) { 110 return "vnd.android.cursor.item/person"; 111 ... snip ... 112 return "vnd.android.cursor.dir/snail-mail"; 113 } else if (pathSegments.size() == 3) { 114 return "vnd.android.cursor.item/snail-mail"; 115 } 116 } 117 } 118 return null; 119 } 120 </pre> 121 */ 122 public class UriMatcher 123 { 124 public static final int NO_MATCH = -1; 125 /** 126 * Creates the root node of the URI tree. 127 * 128 * @param code the code to match for the root URI 129 */ 130 public UriMatcher(int code) 131 { 132 mCode = code; 133 mWhich = -1; 134 mChildren = new ArrayList<UriMatcher>(); 135 mText = null; 136 } 137 138 private UriMatcher() 139 { 140 mCode = NO_MATCH; 141 mWhich = -1; 142 mChildren = new ArrayList<UriMatcher>(); 143 mText = null; 144 } 145 146 /** 147 * Add a URI to match, and the code to return when this URI is 148 * matched. URI nodes may be exact match string, the token "*" 149 * that matches any text, or the token "#" that matches only 150 * numbers. 151 * <p> 152 * Starting from API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR2}, 153 * this method will accept leading slash in the path. 154 * 155 * @param authority the authority to match 156 * @param path the path to match. * may be used as a wild card for 157 * any text, and # may be used as a wild card for numbers. 158 * @param code the code that is returned when a URI is matched 159 * against the given components. Must be positive. 160 */ 161 public void addURI(String authority, String path, int code) 162 { 163 if (code < 0) { 164 throw new IllegalArgumentException("code " + code + " is invalid: it must be positive"); 165 } 166 167 String[] tokens = null; 168 if (path != null) { 169 String newPath = path; 170 // Strip leading slash if present. 171 if (path.length() > 0 && path.charAt(0) == '/') { 172 newPath = path.substring(1); 173 } 174 tokens = PATH_SPLIT_PATTERN.split(newPath); 175 } 176 177 int numTokens = tokens != null ? tokens.length : 0; 178 UriMatcher node = this; 179 for (int i = -1; i < numTokens; i++) { 180 String token = i < 0 ? authority : tokens[i]; 181 ArrayList<UriMatcher> children = node.mChildren; 182 int numChildren = children.size(); 183 UriMatcher child; 184 int j; 185 for (j = 0; j < numChildren; j++) { 186 child = children.get(j); 187 if (token.equals(child.mText)) { 188 node = child; 189 break; 190 } 191 } 192 if (j == numChildren) { 193 // Child not found, create it 194 child = new UriMatcher(); 195 if (token.equals("#")) { 196 child.mWhich = NUMBER; 197 } else if (token.equals("*")) { 198 child.mWhich = TEXT; 199 } else { 200 child.mWhich = EXACT; 201 } 202 child.mText = token; 203 node.mChildren.add(child); 204 node = child; 205 } 206 } 207 node.mCode = code; 208 } 209 210 static final Pattern PATH_SPLIT_PATTERN = Pattern.compile("/"); 211 212 /** 213 * Try to match against the path in a url. 214 * 215 * @param uri The url whose path we will match against. 216 * 217 * @return The code for the matched node (added using addURI), 218 * or -1 if there is no matched node. 219 */ 220 public int match(Uri uri) 221 { 222 final List<String> pathSegments = uri.getPathSegments(); 223 final int li = pathSegments.size(); 224 225 UriMatcher node = this; 226 227 if (li == 0 && uri.getAuthority() == null) { 228 return this.mCode; 229 } 230 231 for (int i=-1; i<li; i++) { 232 String u = i < 0 ? uri.getAuthority() : pathSegments.get(i); 233 ArrayList<UriMatcher> list = node.mChildren; 234 if (list == null) { 235 break; 236 } 237 node = null; 238 int lj = list.size(); 239 for (int j=0; j<lj; j++) { 240 UriMatcher n = list.get(j); 241 which_switch: 242 switch (n.mWhich) { 243 case EXACT: 244 if (n.mText.equals(u)) { 245 node = n; 246 } 247 break; 248 case NUMBER: 249 int lk = u.length(); 250 for (int k=0; k<lk; k++) { 251 char c = u.charAt(k); 252 if (c < '0' || c > '9') { 253 break which_switch; 254 } 255 } 256 node = n; 257 break; 258 case TEXT: 259 node = n; 260 break; 261 } 262 if (node != null) { 263 break; 264 } 265 } 266 if (node == null) { 267 return NO_MATCH; 268 } 269 } 270 271 return node.mCode; 272 } 273 274 private static final int EXACT = 0; 275 private static final int NUMBER = 1; 276 private static final int TEXT = 2; 277 278 private int mCode; 279 private int mWhich; 280 private String mText; 281 private ArrayList<UriMatcher> mChildren; 282 } 283
