diff --git a/Contact.java b/Contact.java
deleted file mode 100644
index c6a5642..0000000
--- a/Contact.java
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * 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 {
-    // 用于缓存电话号码与联系人姓名的映射关系，提高查询效率
-    private static HashMap<String, String> sContactCache;
-    // 日志标签
-    private static final String TAG = "Contact";
-
-    // 查询联系人数据库的SQL选择语句
-    // 这个复杂查询：
-    // 1. 检查电话号码是否匹配（考虑不同格式）
-    // 2. 验证数据类型是电话号码
-    // 3. 确保原始联系人存在于phone_lookup表中
-    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 要查询的电话号码
-     * @return 如果找到则返回联系人姓名，否则返回null
-     */
-    public static String getContact(Context context, String phoneNumber) {
-        // 如果缓存不存在，则初始化
-        if(sContactCache == null) {
-            sContactCache = new HashMap<String, String>();
-        }
-        // 如果缓存中已有结果，直接返回
-        if(sContactCache.containsKey(phoneNumber)) {
-            return sContactCache.get(phoneNumber);
-        }
-        // 准备查询语句，将'+'替换为电话号码的最小匹配模式（处理不同格式）
-        String selection = CALLER_ID_SELECTION.replace("+",
-                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
-        // 查询联系人数据库
-        Cursor cursor = context.getContentResolver().query(
-                Data.CONTENT_URI,         // 联系人数据的内容URI
-                new String [] { Phone.DISPLAY_NAME },   // 只获取显示名称
-                selection,                  // 准备好的查询条件
-                new String[] { phoneNumber },         // 查询参数
-                null);                     // 无排序要求
-        // 处理查询结果
-        if (cursor != null && cursor.moveToFirst()) {
-            try {
-                // 从第一条结果获取联系人姓名
-                String name = cursor.getString(0);
-                // 将结果缓存以备后用
-                sContactCache.put(phoneNumber, name);
-                return name;
-            } catch (IndexOutOfBoundsException e) {
-                Log.e(TAG, " Cursor get string error " + e.toString());
-                return null;
-            } finally {
-                // 始终关闭游标，避免内存泄漏
-                cursor.close();
-            }
-        } else {
-            Log.d(TAG, "No contact matched with number:" + phoneNumber);
-            return null;
-        }
-    }
-}