TL; DR:创建数据库对象时,应为MS Access 2000-2003数据库使用什么Database.FileFormat
常量?
我已经使用jCIFS构建了SAMBA测试应用程序。如果提供了正确的身份验证凭据,无论我在域中的哪台PC上使用它,它都可以创建/覆盖文件。
我也有一个使用uCanAccess / jackcess连接到网络共享上的MDB的应用程序。但是(据我了解),它使用登录用户的凭据,其中许多用户具有只读访问权限。只有系统/网络管理员具有写权限。
所讨论的数据库不受密码保护。 (打开密码时,我不需要输入密码。)
我的意图是让应用程序使用uCanAccess连接中的凭据,在写入数据库之前要求管理员的Samba凭据,以使其不会抛出java.nio.channels.NonWritableChannelException
,如以下堆栈跟踪所示:
java.nio.channels.NonWritableChannelException
at sun.nio.ch.FileChannelImpl.write(FileChannelImpl.java:747)
at com.healthmarketscience.jackcess.impl.PageChannel.writePage(PageChannel.java:310)
at com.healthmarketscience.jackcess.impl.PageChannel.writePage(PageChannel.java:247)
at com.healthmarketscience.jackcess.impl.TableImpl.writeDataPage(TableImpl.java:1980)
at com.healthmarketscience.jackcess.impl.TableImpl.addRows(TableImpl.java:2229)
at com.healthmarketscience.jackcess.impl.TableImpl.addRow(TableImpl.java:2067)
at net.ucanaccess.converters.UcanaccessTable.addRow(UcanaccessTable.java:44)
at net.ucanaccess.commands.InsertCommand.insertRow(InsertCommand.java:101)
at net.ucanaccess.commands.InsertCommand.persist(InsertCommand.java:148)
at net.ucanaccess.jdbc.UcanaccessConnection.flushIO(UcanaccessConnection.java:315)
at net.ucanaccess.jdbc.UcanaccessConnection.commit(UcanaccessConnection.java:205)
at net.ucanaccess.jdbc.AbstractExecute.executeBase(AbstractExecute.java:217)
at net.ucanaccess.jdbc.Execute.execute(Execute.java:46)
at net.ucanaccess.jdbc.UcanaccessPreparedStatement.execute(UcanaccessPreparedStatement.java:228)
at myapp.db.Digger.addTransaction(Digger.java:993)
at myapp.tasks.TransactionRunnable.run(TransactionRunnable.java:42)
at java.lang.Thread.run(Thread.java:745)
更新:我尝试使用Gord Thompson和J. T. Alhborn,shown here的smbFileChannel
类。我的代码基于该答案中显示的主类,如下所示:
// Ask the user for login credentials and the path to the database
String smbURL = (chosenDir.endsWith("/") ? chosenDir : chosenDir + '/')
+ dbName;
System.out.println("DB Path to use for URL: " + smbURL);
URL u = new URL(smbURL);
try (
// construct the SMB DB URL
SmbFileChannel sfc = new SmbFileChannel(smbURL);
Database db = new DatabaseBuilder().setChannel(sfc)
.setFileFormat(Database.FileFormat.GENERIC_JET4).create();
) {
// Model the table
Table tbl = new TableBuilder("Transactions")
.addColumn(new ColumnBuilder("TransactionID", DataType.LONG).setAutoNumber(true))
.addColumn(new ColumnBuilder("ControllerID", DataType.LONG).setAutoNumber(false))
.addColumn(new ColumnBuilder("ReaderID", DataType.LONG).setAutoNumber(false))
.addColumn(new ColumnBuilder("Event", DataType.LONG).setAutoNumber(false))
.addColumn(new ColumnBuilder("Timestamp", DataType.SHORT_DATE_TIME).setAutoNumber(false))
.addColumn(new ColumnBuilder("Number", DataType.LONG).setAutoNumber(false))
.addIndex(new IndexBuilder(IndexBuilder.PRIMARY_KEY_NAME).addColumns("TransactionID").setPrimaryKey())
.toTable(db);
// Add the row
Map<String, Object> values = new HashMap<>();
values.put("ControllerID", cid);
values.put("ReaderID", rid);
values.put("Event", evtNum);
values.put("Timestamp", ts); // Long; must be converted to DataType.SHORT_DATE_TIME
values.put("Number", accNum);
tbl.addRowFromMap(values);
} catch (IOException IOEx) {
System.err.println(
"Failed to write record to Transactions table in database: "
+ IOEx.getMessage()
);
IOEx.printStackTrace(System.err);
} catch (Exception ex) {
System.err.println(
'[' + ex.getClass().getSimpleName() + "]: Failed to write record to "
+ "Transactions table in database: " + ex.getMessage()
);
ex.printStackTrace(System.err);
}
执行上述代码将产生以下输出:
DB Path to use for URL: smb://machine.vpnName/Storage/me/dbs/DBName.mdb
Failed to write record to Transactions table in database: Logon failure: account currently disabled.
jcifs.smb.SmbAuthException: Logon failure: account currently disabled.
at jcifs.smb.SmbTransport.checkStatus(SmbTransport.java:546)
at jcifs.smb.SmbTransport.send(SmbTransport.java:663)
at jcifs.smb.SmbSession.sessionSetup(SmbSession.java:390)
at jcifs.smb.SmbSession.send(SmbSession.java:218)
at jcifs.smb.SmbTree.treeConnect(SmbTree.java:176)
at jcifs.smb.SmbFile.doConnect(SmbFile.java:911)
at jcifs.smb.SmbFile.connect(SmbFile.java:957)
at jcifs.smb.SmbFile.connect0(SmbFile.java:880)
at jcifs.smb.SmbFile.open0(SmbFile.java:975)
at jcifs.smb.SmbFile.open(SmbFile.java:1009)
at jcifs.smb.SmbRandomAccessFile.<init>(SmbRandomAccessFile.java:57)
at jcifs.smb.SmbRandomAccessFile.<init>(SmbRandomAccessFile.java:42)
at samba.SmbFileChannel.<init>(SmbFileChannel.java:30)
at samba.SambaLanWriteTest.writeTest(SambaLanWriteTest.java:130)
at samba.SambaLanWriteTest.main(SambaLanWriteTest.java:181)
使用Windows File Explorer时,我对有关数据库文件的测试副本具有写访问权。提示时我选择了那个。
更新2:正如汤普森的示例所示,我意识到我忽略了将用户名和密码添加到smb://
URL中。我将代码更改为此:
String smbCred = "smb://" + auth.getUsername() + ":" + auth.getPassword() + "@",
fixer = chosenDir.replace("\\", "/").replace("smb://", smbCred),
smbURL = fixer + dbName;
System.out.println("DB Path to use for URL: " + smbURL);
// URL u = new URL(smbURL);
我遇到的下一个问题是我的密码包含特殊个非法字符(例如'@',':',';','='和'?')。我通过在java.net.URLEncoder.encode()
和auth.getUsername()
上使用auth.getPassword()
进行了转义,因此在创建MalformedURLException
时代码不会抛出SmbChannel
。但是,我遇到的下一个异常如下:
Failed to write record to Transactions table in database: File format GENERIC_JET4 [VERSION_4] does not support file creation for null
java.io.IOException: File format GENERIC_JET4 [VERSION_4] does not support file creation for null
at com.healthmarketscience.jackcess.impl.DatabaseImpl.create(DatabaseImpl.java:444)
在创建Database.FileFormat
对象时,我应该为MS Access 2000-2003数据库使用哪个Database
常量?
答案 0 :(得分:1)
原来,我需要使用Database.FileFormat.V2000
。
此后,一切都是顺风顺水的(尽管我仍然需要弄清楚如何使Long时间戳正确转换)。