MiNotes/doc/成员代码分析/jhw/Contact.java

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;
//change
public class Contact { //联系人
    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);
        }

        String selection = CALLER_ID_SELECTION.replace("+",
                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
        // 查找数据库中phoneNumber的信息
        Cursor cursor = context.getContentResolver().query(
                Data.CONTENT_URI,
                new String [] { Phone.DISPLAY_NAME },
                selection,
                new String[] { phoneNumber },
                null);

        // 判定查询结果 
        // moveToFirst()返回第一条
        if (cursor != null && cursor.moveToFirst()) {
            try {
                // 找到相关信息
                String name = cursor.getString(0);
                sContactCache.put(phoneNumber, name);
                return name;
                // 异常
            } catch (IndexOutOfBoundsException e) {
                Log.e(TAG, " Cursor get string error " + e.toString());
                return null;
            } finally {
                cursor.close();
            }
            // 未找到相关信息
        } else {
            Log.d(TAG, "No contact matched with number:" + phoneNumber);
            return null;
        }
    }
}