diff --git a/doc/标注/210340069_申佃东/Contact.java b/doc/标注/210340069_申佃东/Contact.java
new file mode 100644
index 0000000..62fad38
--- /dev/null
+++ b/doc/标注/210340069_申佃东/Contact.java
@@ -0,0 +1,59 @@
+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 {//联系人类
+    private static HashMap<String, String> sContactCache;
+    private static final String TAG = "Contact";
+          //定义字符串CALLER_ID_SELECTION 
+    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 = '+')";
+    //获取联系人
+    public static String getContact(Context context, String phoneNumber) {
+        if(sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+     //查找HashMap中是否已有phoneNumber信息
+        if(sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);//有则返回phoneNumber对应信息
+        }
+
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+//如果没有，则查找数据库中phoneNumber的信息
+        Cursor cursor = context.getContentResolver().query(
+                Data.CONTENT_URI,//指定联系人提供程序的数据表的 URI，其中包含所有可用的联系人信息。
+                new String [] { Phone.DISPLAY_NAME },//只应返回联系人的显示名称
+                selection,
+                new String[] { phoneNumber },//用于指定要与筛选期匹配的值
+                null);
+        //判定查询结果
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                String name = cursor.getString(0);//cursor不为空则从其第一列中检索与电话号码关联的名称
+                sContactCache.put(phoneNumber, name);
+                return name;//返回联系人名称
+            } catch (IndexOutOfBoundsException e) {
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;//如果发生 IndexOutOfBoundsException，则会记录一条错误消息并返回 null
+            } finally {
+                cursor.close();//关闭
+            }
+        } else {
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);//如果未找到具有给定电话号码的联系人
+
+            return null;//返回null
+        }
+    }
+}