Android短信和彩信探秘threads

Android源代碼在 彩信sms 表和彩信 pdu表，增加了一個觸發器

1. CREATE TRIGGER delete_obsolete_threads_pdu AFTER
2. DELETE ON pdu BEGIN
3. DELETE FROM threads
4. WHERE _id = old.thread_id AND _id NOT IN
5. (SELECT thread_id FROM sms UNION SELECT thread_id from pdu);
6. END

仔細看下就明白，如果threads表沒有sms和pdu外部引用的時候，這條thread就會被刪除。

thread被刪除後，你再插入一條短信或者彩信（當然是代碼插入），這時候因為沒有thread id，所以就會不顯示。

有人可能想到對threads表一起進行維護不就行了嗎？ 很不幸 ，系統對這個表的providers並不完全開放，只能用於查找。

但我們這時候又需要thread_id, 我對源代碼進行了一些修改，把thread類提取了出來，僅供大家參考

1. package com.sweetop.provider;
3. import java.util.HashSet;
4. import java.util.Set;
5. import java.util.regex.Matcher;
6. import java.util.regex.Pattern;
8. import android.content.Context;
9. import android.database.Cursor;
10. import android.net.Uri;
11. import android.text.TextUtils;
12. import android.util.Log;
13. import android.util.Patterns;
15. public final class Threads implements ThreadsColumns {
16. private static final String[] ID_PROJECTION = { BaseColumns._ID };
17. private static final String STANDARD_ENCODING = "UTF-8";
18. private static final Uri THREAD_ID_CONTENT_URI = Uri
19. .parse("content://mms-sms/threadID");
20. public static final Uri CONTENT_URI = Uri.withAppendedPath(
21. Uri.parse("content://mms-sms/"), "conversations");
22. public static final Uri OBSOLETE_THREADS_URI = Uri.withAppendedPath(
23. CONTENT_URI, "obsolete");
24. public static final Pattern NAME_ADDR_EMAIL_PATTERN = Pattern
25. .compile("\\s*(\"[^\"]*\"|[^<>\"]+)\\s*<([^<>]+)>\\s*");
27. public static final int COMMON_THREAD = 0;
28. public static final int BROADCAST_THREAD = 1;
30. // No one should construct an instance of this class.
31. private Threads() {
32. }
34. /**
35. * This is a single-recipient version of getOrCreateThreadId. It's
36. * convenient for use with SMS messages.
37. */
38. public static long getOrCreateThreadId(Context context, String recipient) {
39. Set<String> recipients = new HashSet<String>();
41. recipients.add(recipient);
42. return getOrCreateThreadId(context, recipients);
43. }
45. /**
46. * Given the recipients list and subject of an unsaved message, return its
47. * thread ID. If the message starts a new thread, allocate a new thread ID.
48. * Otherwise, use the appropriate existing thread ID.
49. *
50. * Find the thread ID of the same set of recipients (in any order, without
51. * any additions). If one is found, return it. Otherwise, return a unique
52. * thread ID.
53. */
54. public static long getOrCreateThreadId(Context context,
55. Set<String> recipients) {
56. Uri.Builder uriBuilder = THREAD_ID_CONTENT_URI.buildUpon();
58. for (String recipient : recipients) {
59. if (isEmailAddress(recipient)) {
60. recipient = extractAddrSpec(recipient);
61. }
63. uriBuilder.appendQueryParameter("recipient", recipient);
64. }
66. Uri uri = uriBuilder.build();
67. // if (DEBUG) Log.v(TAG, "getOrCreateThreadId uri: " + uri);
69. Cursor cursor = context.getContentResolver().query(uri, ID_PROJECTION,
70. null, null, null);
71. if (true) {
72. Log.v("Threads",
73. "getOrCreateThreadId cursor cnt: " + cursor.getCount());
74. }
75. if (cursor != null) {
76. try {
77. if (cursor.moveToFirst()) {
78. return cursor.getLong(0);
79. } else {
80. Log.e("Threads", "getOrCreateThreadId returned no rows!");
81. }
82. } finally {
83. cursor.close();
84. }
85. }
87. Log.e("Threads",
88. "getOrCreateThreadId failed with uri " + uri.toString());
89. throw new IllegalArgumentException(
90. "Unable to find or allocate a thread ID.");
91. }
93. public static String extractAddrSpec(String address) {
94. Matcher match = NAME_ADDR_EMAIL_PATTERN.matcher(address);
96. if (match.matches()) {
97. return match.group(2);
98. }
99. return address;
100. }
102. /**
103. * Returns true if the address is an email address
104. *
105. * @param address
106. * the input address to be tested
107. * @return true if address is an email address
108. */
109. public static boolean isEmailAddress(String address) {
110. if (TextUtils.isEmpty(address)) {
111. return false;
112. }
114. String s = extractAddrSpec(address);
115. Matcher match = Patterns.EMAIL_ADDRESS.matcher(s);
116. return match.matches();
117. }
118. }

1. Threads.getOrCreateThreadId(this, address)

address是發送方的手機地址