java.lang.NullPointerException at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked()

异常信息：

01-27 11:39:34.379: E/AndroidRuntime(17313): FATAL EXCEPTION: Thread-31353

01-27 11:39:34.379: E/AndroidRuntime(17313): java.lang.NullPointerException

01-27 11:39:34.379: E/AndroidRuntime(17313): at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:224)

01-27 11:39:34.379: E/AndroidRuntime(17313): at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:188)

01-27 11:39:34.379: E/AndroidRuntime(17313): at com.sky.language.db.UserTable.getUsers(UserTable.java:53)

01-27 11:39:34.379: E/AndroidRuntime(17313): at com.sky.language.core.SessionManager.initDatabase(SessionManager.java:163)

01-27 11:39:34.379: E/AndroidRuntime(17313): at com.sky.language.core.SessionManager$1.run(SessionManager.java:141)

01-27 11:39:34.379: E/AndroidRuntime(17313): at java.lang.Thread.run(Thread.java:856)

我的原因是在调用SQLiteOpenHelper的构造函数的时候，Context值为null. 在正确传递Context后，问题解决了。

具体情况，具体分析！