android的UriMatcher类

package fkshl.activity.contentProvider;/* Copyright (C) 2006 The Android Open Source Project   *   * Licensed under the Apache License, Version 2.0 (the "License");   * you may not use this file except in compliance with the License.   * You may obtain a copy of the License at   *   *      http://www.apache.org/licenses/LICENSE-2.0   *   * Unless required by applicable law or agreed to in writing, software   * distributed under the License is distributed on an "AS IS" BASIS,   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   * See the License for the specific language governing permissions and   * limitations under the License.   */import java.util.ArrayList;import java.util.List;import java.util.regex.Pattern;import android.net.Uri;public class UriMatcher{public static final int NO_MATCH = -1;/*** *  * Creates the root node of the URI tree. *  *  *  * @param code *            the code to match for the root URI */public UriMatcher(int code){mCode = code;mWhich = -1;mChildren = new ArrayList<UriMatcher>();mText = null;}private UriMatcher(){mCode = NO_MATCH;mWhich = -1;mChildren = new ArrayList<UriMatcher>();mText = null;}/*** *  * Add a URI to match, and the code to return when this URI is *  * matched. URI nodes may be exact match string, the token "*" *  * that matches any text, or the token "#" that matches only *  * numbers. *  *  *  * @param authority *            the authority to match *  * @param path *            the path to match. * may be used as a wild card for *  *            any text, and # may be used as a wild card for numbers. *  * @param code *            the code that is returned when a URI is matched *  *            against the given components. Must be positive. */public void addURI(String authority, String path, int code){if (code < 0) {throw new IllegalArgumentException("code " + code+ " is invalid: it must be positive");}//以"/"分隔pathString[] tokens = path != null ? PATH_SPLIT_PATTERN.split(path) : null;        //判断分隔后的数组长度.并取其值int numTokens = tokens != null ? tokens.length : 0;//当前对象UriMatcher node = this;for (int i = -1; i < numTokens; i++) {//当前循环变量小于0就取authority,否则就获取分隔后的数组的字符,并赋值给tokenString token = i < 0 ? authority : tokens[i];//把当前对象的集合赋值给childrenArrayList<UriMatcher> children = node.mChildren;//获取其长度int numChildren = children.size();          UriMatcher child;int j;for (j = 0; j < numChildren; j++) {//获取children对象的孩子child = children.get(j);//判断当前的token和child对象中的mText是否相等if (token.equals(child.mText)) {//把child 赋值给 node;node = child;break;}}//获取循环变量j并判断是否等于children对应的大小.也就是判断是否是最后一个if (j == numChildren) {// Child not found, create it//没有发现孩子,并创建child = new UriMatcher();///判断当前的token是否等于"#"if (token.equals("#")) {//mWhich=1child.mWhich = NUMBER;} else if (token.equals("*")) {//mWhich=2child.mWhich = TEXT;} else {//mWhich=0child.mWhich = EXACT;}//mText=当前的tokenchild.mText = token;//添加到mChildren集合中node.mChildren.add(child);//node = child;node = child;}}//node.mCode = code;node.mCode = code;}static final Pattern PATH_SPLIT_PATTERN = Pattern.compile("/");/*** *  * Try to match against the path in a url. *  *  *  * @param uri *            The url whose path we will match against. *  *  *  * @return The code for the matched node (added using addURI), *  *         or -1 if there is no matched node. */public int match(Uri uri){final List<String> pathSegments = uri.getPathSegments();final int li = pathSegments.size();UriMatcher node = this;if (li == 0 && uri.getAuthority() == null) {return this.mCode;}for (int i = -1; i < li; i++) {String u = i < 0 ? uri.getAuthority() : pathSegments.get(i);ArrayList<UriMatcher> list = node.mChildren;if (list == null) {break;}node = null;int lj = list.size();for (int j = 0; j < lj; j++) {UriMatcher n = list.get(j);which_switch:switch (n.mWhich) {case EXACT:if (n.mText.equals(u)) {node = n;}        break;case NUMBER:int lk = u.length();for (int k = 0; k < lk; k++) {char c = u.charAt(k);             if (c < '0' || c > '9') {break which_switch;}}node = n;break;case TEXT:node = n;break;}if (node != null) {     break;}}if (node == null) {return NO_MATCH;}}return node.mCode;}private static final int EXACT = 0;private static final int NUMBER = 1;private static final int TEXT = 2;private int mCode;private int mWhich;private String mText;private final ArrayList<UriMatcher> mChildren;}这是android源码.由于不懂所以就把它粘贴的项目中.所以包自然就改成自己项目的了..package fkshl.activity.contentProvider;import java.util.HashMap;import java.util.Map;import android.content.ContentProvider;import android.content.ContentUris;import android.content.ContentValues;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteQueryBuilder;import android.net.Uri;import android.text.TextUtils;import fkshl.activity.contentProviderMetaData.ContentProviderMetaData;import fkshl.activity.contentProviderMetaData.ContentProviderMetaData.UserTableMetaData;import fkshl.activity.dataBase.DBHelper;public class FkshlContentProvider extends ContentProvider {public static final UriMatcher URI_MATCHER;public static final int FKSHL_TABLE = 1;public static final int FKSHL_TABLE_COLUMN = 2;public static final Map<String, String> COLUM_MAPPIGN;public DBHelper dbHelper;static {/** * uri验证 */URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);URI_MATCHER.addURI(ContentProviderMetaData.AUTHORIY, "users", 1);URI_MATCHER.addURI(ContentProviderMetaData.AUTHORIY, "users/#", 2);/** * 列的映射 */COLUM_MAPPIGN = new HashMap<String, String>();COLUM_MAPPIGN.put(UserTableMetaData._ID, UserTableMetaData._ID);COLUM_MAPPIGN.put(UserTableMetaData.COLUMN_NAME, UserTableMetaData.COLUMN_NAME);}@Overridepublic int delete(Uri uri, String selection, String[] selectionArgs) {// TODO Auto-generated method stubreturn 0;}@Overridepublic String getType(Uri uri) {// TODO Auto-generated method stubswitch (URI_MATCHER.match(uri)) {case FKSHL_TABLE:return UserTableMetaData.CONTENT_TYPE;case FKSHL_TABLE_COLUMN:return UserTableMetaData.CONTENT_TYPE_ITEM;default:throw new IllegalArgumentException("Unknown URI!!!!!" + uri);}}@Overridepublic Uri insert(Uri uri, ContentValues values) {// TODO Auto-generated method stubSQLiteDatabase database = dbHelper.getWritableDatabase();Long rowId = database.insert(ContentProviderMetaData.TABLE_NAME, null, values);if (rowId > 0) {Uri empuri = ContentUris.withAppendedId(UserTableMetaData.CONTENT_URI, rowId);getContext().getContentResolver().notifyChange(empuri, null);System.out.println("insert success!!!");}return null;}@Overridepublic boolean onCreate() {// TODO Auto-generated method stubdbHelper = new DBHelper(getContext(), ContentProviderMetaData.DATABASE_NAME);dbHelper.getReadableDatabase();System.out.println("create database success!!");return true;}@Overridepublic Cursor query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder) {SQLiteQueryBuilder builder = new SQLiteQueryBuilder();// TODO Auto-generated method stubswitch (URI_MATCHER.match(uri)) {case FKSHL_TABLE:builder.setTables(UserTableMetaData.TABLE_NAME);builder.setProjectionMap(COLUM_MAPPIGN);break;case FKSHL_TABLE_COLUMN:builder.setTables(UserTableMetaData.TABLE_NAME);builder.setProjectionMap(COLUM_MAPPIGN);builder.appendWhere(UserTableMetaData.COLUMN_NAME + "="+ uri.getPathSegments().get(1));break;default:throw new IllegalArgumentException("uri error !!!!" + uri);}String orderBy;if (TextUtils.isEmpty(sortOrder)) {orderBy = UserTableMetaData.ORDER_BY + " Desc";} else {orderBy = sortOrder;}SQLiteDatabase database = dbHelper.getReadableDatabase();Cursor c =builder.query(database, projection, selection, selectionArgs, null, null, orderBy);c.setNotificationUri(getContext().getContentResolver(), uri);System.out.println("seach end!!!!");return c;}@Overridepublic int update(Uri uri, ContentValues values, String selection,String[] selectionArgs) {// TODO Auto-generated method stubreturn 0;}}做的时间发现一个问题.这是之前发现在按官方提示做的.URI_MATCHER.addURI(ContentProviderMetaData.AUTHORIY, "/users", 1);URI_MATCHER.addURI(ContentProviderMetaData.AUTHORIY, "/users/#", 2);可是在getType中怎么都走default.都是抛异常.05-22 09:39:23.449: ERROR/AndroidRuntime(581): java.lang.IllegalArgumentException: uri error !!!!content://fkshl.activity.contentProvider.FkshlContentProvider/users最后看了源码,改成了.URI_MATCHER.addURI(ContentProviderMetaData.AUTHORIY, "users", 1);URI_MATCHER.addURI(ContentProviderMetaData.AUTHORIY, "users/#", 2);这样就好.原因是在add方法中它会以"/"分隔users/#,然后把分隔后的字符串像树型的一级一级保存在mChildren中.如果在users/#前面加"/",哪么就导致在"/"之前有一个空字符(content://fkshl.activity.contentProvider.FkshlContentProvider//users),而在我的项目中调用getType方法传过来时的uir中没有这样的一个空字符(content://fkshl.activity.contentProvider.FkshlContentProvider/users)没有.
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