Update Contact.java

app/src/main/java/net/micode/notes/data/Contact.java

@@ -26,47 +26,48 @@ import android.util.Log;
 import java.util.HashMap;
 
 public class Contact {
-    private static HashMap<String, String> sContactCache;
-    private static final String TAG = "Contact";
+    private static HashMap<String, String> sContactCache;// 用于缓存联系人信息的哈希映射表
+    private static final String TAG = "Contact";// 日志标签
 
+    // 查询联系人的条件语句
     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
     public static String getContact(Context context, String phoneNumber) {
         if(sContactCache == null) {
-            sContactCache = new HashMap<String, String>();
+            sContactCache = new HashMap<String, String>();// 如果缓存为空，则创建一个新的哈希映射表
         }
 
-        if(sContactCache.containsKey(phoneNumber)) {
+        if(sContactCache.containsKey(phoneNumber)) {// 如果缓存中已存在该电话号码的联系人信息，则直接返回
             return sContactCache.get(phoneNumber);
         }
 
         String selection = CALLER_ID_SELECTION.replace("+",
-                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));// 根据电话号码生成查询条件语句
         Cursor cursor = context.getContentResolver().query(
                 Data.CONTENT_URI,
                 new String [] { Phone.DISPLAY_NAME },
                 selection,
                 new String[] { phoneNumber },
-                null);
+                null);// 执行查询操作，获取联系人的姓名
 
-        if (cursor != null && cursor.moveToFirst()) {
+        if (cursor != null && cursor.moveToFirst()) {// 如果查询结果非空且有数据
             try {
-                String name = cursor.getString(0);
-                sContactCache.put(phoneNumber, name);
-                return name;
+                String name = cursor.getString(0);// 获取联系人姓名
+                sContactCache.put(phoneNumber, name);// 将联系人信息添加到缓存中
+                return name;// 返回联系人姓名
             } catch (IndexOutOfBoundsException e) {
-                Log.e(TAG, " Cursor get string error " + e.toString());
+                Log.e(TAG, " Cursor get string error " + e.toString());// 输出异常信息
                 return null;
             } finally {
-                cursor.close();
+                cursor.close();// 关闭游标
             }
         } else {
-            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);// 输出未找到匹配联系人的日志信息
             return null;
         }
     }