为什么我的异常处理程序没有捕获Android SQLite插入错误？

Question

我是第一次使用SQLite,并且我正在尝试学习它的异常处理,所以我在我的测试应用程序中强制插入错误.发生异常,我看到它写入了Eclipse LogCat输出窗口.但是它不会被代码捕获.我在这里看到了其他关于确保使用正确的异常类型的问题,并认为我已经做对了.知道我错过了什么吗？

在我的主要活动中的以下语句中,myTable是一个扩展我自己AbstractDbAdapter的类(它有一个DatabaseHelper扩展的类SQLiteOpenHelper).

try {
    myTable.create("dupkey");
}
catch (android.database.sqlite.SQLiteConstraintException e) {
    Log.e(TAG, "SQLiteConstraintException:" + e.getMessage());
}
catch (android.database.sqlite.SQLiteException e) {
    Log.e(TAG, "SQLiteException:" + e.getMessage());
} 
catch (Exception e) {
    Log.e(TAG, "Exception:" + e.getMessage());
}

样本堆栈跟踪:

Error inserting id="dupkey" last_seen_ts=1360624732 first_seen_ts=1360624732 android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed
  at android.database.sqlite.SQLiteStatement.native_execute(Native Method)
  at android.database.sqlite.SQLiteStatement.execute(SQLiteStatement.java:61)
  at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1582)
  at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1426)
  at com.myCompany.testApp.myTable_DbAdapter.create(myTable_DbAdapter.java:51)

在myTable和AbstractDbAdapter类:

public class myTable_DbAdapter extends AbstractDbAdapter {

    private static final String DATABASE_TABLE = "myTable";

    // column names -- keys for ContentValues()
    public static final String KEY_ID = "id";
    public static final String KEY_FIRST_SEEN = "first_seen_ts";
    public static final String KEY_LAST_SEEN = "last_seen_ts";

    public myTable_DbAdapter(Context ctx) {
        super(ctx);
    }

    public long create(String id) {
        long firstSeen = System.currentTimeMillis() / 1000;  // SQLite timestamps are in seconds

        ContentValues args = new ContentValues();
        args.put(KEY_ID, id);
        args.put(KEY_FIRST_SEEN, firstSeen);
        args.put(KEY_LAST_SEEN, firstSeen);  // defaults to firstSeen for a new entry

        return mDb.insert(DATABASE_TABLE, null, args);
    }
}

public abstract class AbstractDbAdapter {

    protected static final String TAG = "AbstractDbAdapter";

    protected DatabaseHelper mDbHelper = null;
    protected SQLiteDatabase mDb = null;

    protected static final String TABLE_CREATE_MYTABLE =
        "create table myTable (" +
        "  id text primary key not null" +
        ", first_seen_ts integer not null" +
        ", last_seen_ts integer not null" +
        ");";

    protected static final String DATABASE_NAME = "myDB";
    protected static final int DATABASE_VERSION = 1;

    protected final Context mCtx;

    protected static class DatabaseHelper extends SQLiteOpenHelper {

        DatabaseHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            // Note: SQLite requires one execSQL per table
            db.execSQL(TABLE_CREATE_MYTABLE);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion + ", which destroys existing data.");
            db.execSQL("DROP TABLE IF EXISTS myTable");
            onCreate(db);
        }
    }

    public AbstractDbAdapter(Context ctx) {
        this.mCtx = ctx;
    }

    public AbstractDbAdapter open() throws SQLException {
        mDbHelper = new DatabaseHelper(mCtx);
        mDb = mDbHelper.getWritableDatabase();
        return this;
    }

    public void close() {
        if (mDb != null) {
            mDb.close();
            mDb = null;
        }
        if (mDbHelper != null) {
            mDbHelper.close();
            mDbHelper = null;
        }
    }

}

Answer 1

我在这里找到了答案:SQLiteConstraintException未被捕获

SQLiteDatabase.insert()方法不会引发异常.D'哦!

对于像我这样的其他SQLite新手,如果要在插入数据库时​​捕获异常,请使用SQLite.insertOrThrow()方法.它将抛出一个异常,然后您可以捕获并处理它.