test123/Contact.java

/*
 * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
 *
 * 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.
 */

package net.micode.notes.data;

import android.content.Context;
import android.database.Cursor;
import android.provider.ContactsContract.CommonDataKinds.Phone;
import android.provider.ContactsContract.Data;
import android.telephony.PhoneNumberUtils;
import android.util.Log;

import java.util.HashMap;

public class Contact {
    private static HashMap<String, String> sContactCache;// 缓存联系人信息，以电话号码为键，联系人姓名为值
    private static final String TAG = "Contact";// 日志标签
 // 用于查询联系人的SQL选择语句，使用PHONE_NUMBERS_EQUAL函数比较电话号码
    private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER
    + ",?) AND " + Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'"
    + " AND " + Data.RAW_CONTACT_ID + " IN "
            + "(SELECT raw_contact_id "
            + " FROM phone_lookup"
            + " WHERE min_match = '+')";
  /**
   * 根据电话号码获取联系人姓名。
   * @param context 应用上下文
   * @param phoneNumber 电话号码
   * @return 联系人姓名，如果没有找到则返回null
   */
    public static String getContact(Context context, String phoneNumber) {
        // 初始化联系人缓存
        if(sContactCache == null) {
            sContactCache = new HashMap<String, String>();
        }
// 如果缓存中已存在该电话号码的联系人信息，直接返回
        if(sContactCache.containsKey(phoneNumber)) {
            return sContactCache.get(phoneNumber);
        }
   // 替换SQL选择语句中的占位符，使用PhoneNumberUtils转换电话号码
        String selection = CALLER_ID_SELECTION.replace("+",
                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
        Cursor cursor = context.getContentResolver().query( // 查询联系人信息
                Data.CONTENT_URI,
                new String [] { Phone.DISPLAY_NAME },// 查询联系人姓名
                selection,
                new String[] { phoneNumber },// 查询条件
                null);
 // 如果查询结果不为空，处理查询结果
        if (cursor != null && cursor.moveToFirst()) {
            try {
                String name = cursor.getString(0); // 获取联系人姓名
                sContactCache.put(phoneNumber, name); // 将结果存入缓存
                return name;
            } catch (IndexOutOfBoundsException e) {   // 捕获并记录异常
                Log.e(TAG, " Cursor get string error " + e.toString());
                return null;
            } finally {
                cursor.close(); // 关闭游标
            }
        } else { 
            // 如果没有找到匹配的联系人，记录日志并返回null
            Log.d(TAG, "No contact matched with number:" + phoneNumber);
            return null;
        }
    }
}