使用 Jackcess 和 JCIFS 来操作 SMB 共享上的 Access 数据库

Question

我需要使用 Jackcess 在 Java 中处理 MS Access 文件。该文件位于 SMB 共享上，因此我假设我必须使用 JCIFS。

我试过了

    String testdirectory = "smb://" + "file location"; 

    SmbFile testsmbdir = null;

    try{
            testsmbdir = new SmbFile(testdirectory,auth);
    }catch(Exception e){
                e.printStackTrace();
    }


    SmbFileInputStream smbFilestream = new SmbFileInputStream(testsmbdir);
    db = DatabaseBuilder.open(testsmbdir);

但是，它说 SMBFile 无法转换为

的文件

db = DatabaseBuilder.open(testsmbdir)"

行。另外，如果我尝试使用 "smbFilestream"，它会说它也无法将 SmbFileInputStream 转换为 File。

我必须将文件复制到本地机器还是完全不同的东西？如果我该怎么办？

（顺便说一下，我是 windows 用户。我只是将我的应用程序转换为 Mac，如果我的行话不对，很抱歉。）

Answer 1

在回复 Jackcess 论坛 here 上的一个帖子时，James 建议

it should be relatively straightforward to implement a version of FileChannel which works with a SmbRandomAccessFile

我刚刚在 Eclipse 中名为 smb4jackcess 的 Maven 项目中尝试了它，并且无需编写太多代码就可以正常工作。我创建的 class 被命名为 SmbFileChannel:

// FileChannel using jcifs.smb.SmbRandomAccessFile

package smb4jackcess;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;

import jcifs.smb.SmbException;
import jcifs.smb.SmbFile;
import jcifs.smb.SmbRandomAccessFile;

public class SmbFileChannel extends FileChannel {
    private final SmbRandomAccessFile _file;
    private long _length;

    public SmbFileChannel(String smbURL) throws SmbException, MalformedURLException, UnknownHostException {
        _file = new SmbRandomAccessFile(smbURL, "rw", SmbFile.FILE_NO_SHARE);
        _length = _file.length();
    }

    @Override
    public void force(boolean metaData) throws SmbException, MalformedURLException, UnknownHostException {
        // do nothing
    }

    @Override
    public FileLock lock(long position, long size, boolean shared) {
        throw new UnsupportedOperationException();
    }

    @Override
    public MappedByteBuffer map(MapMode mode, long position, long size) {
        throw new UnsupportedOperationException();
    }

    @Override
    public long position() throws SmbException {
        return _file.getFilePointer();
    }

    @Override
    public FileChannel position(long newPosition) throws SmbException {
        _file.seek(newPosition);
        return this;
    }

    @Override
    public int read(ByteBuffer dst) {
        throw new UnsupportedOperationException();
    }

    @Override
    public int read(ByteBuffer dst, long position) throws SmbException {
        byte[] b = new byte[dst.remaining()];
        _file.seek(position);
        int bytesRead =_file.read(b);
        dst.put(b);
        return bytesRead;
    }

    @Override
    public long read(ByteBuffer[] dsts, int offset, int length) {
        throw new UnsupportedOperationException();
    }

    @Override
    public long size() throws SmbException {
        return _length;
    }

    @Override
    public long transferFrom(ReadableByteChannel src, long position, long count) throws IOException {
        ByteBuffer bb = ByteBuffer.allocate((int)count);
        int bytesWritten = src.read(bb);
        bb.rewind();
        bb.limit(bytesWritten);
        this.write(bb, position);
        return bytesWritten;
    }

    @Override
    public long transferTo(long position, long count, WritableByteChannel target) {
        throw new UnsupportedOperationException();
    }

    @Override
    public FileChannel truncate(long newSize) throws SmbException {
        if (newSize < 0L) {
            throw new IllegalArgumentException("negative size");
        }
        _file.setLength(newSize);
        _length = newSize;
        return this;
    }

    @Override
    public FileLock tryLock(long position, long size, boolean shared) {
        throw new UnsupportedOperationException();
    }

    @Override
    public int write(ByteBuffer src) throws SmbException {
        throw new UnsupportedOperationException();
    }

    @Override
    public int write(ByteBuffer src, long position) throws SmbException {
        byte[] b = new byte[src.remaining()];
        src.get(b);
        _file.seek(position);
        _file.write(b);

        long endPos = position + b.length;
        if(endPos > _length) {
            _length = endPos;
        }

        return b.length;
    }

    @Override
    public long write(ByteBuffer[] srcs, int offset, int length) {
        throw new UnsupportedOperationException();
    }

    @Override
    protected void implCloseChannel() throws SmbException {
        _file.close();
    }

}

我使用的主要class是

package smb4jackcess;

import java.nio.channels.FileChannel;

import com.healthmarketscience.jackcess.Column;
import com.healthmarketscience.jackcess.ColumnBuilder;
import com.healthmarketscience.jackcess.DataType;
import com.healthmarketscience.jackcess.Database;
import com.healthmarketscience.jackcess.Database.FileFormat;
import com.healthmarketscience.jackcess.DatabaseBuilder;
import com.healthmarketscience.jackcess.IndexBuilder;
import com.healthmarketscience.jackcess.Table;
import com.healthmarketscience.jackcess.TableBuilder;

public class Smb4jackcessMain {

    public static void main(String[] args) {

        String smbURL = "smb://gord:mypassword@SERVERNAME/sharename/etc/newdb.accdb";
        try (SmbFileChannel sfc = new SmbFileChannel(smbURL)) {

            // create a brand new database file                
            Database db = new DatabaseBuilder()
                    .setChannel(sfc)
                    .setFileFormat(FileFormat.V2010)
                    .create();

            // add a table to it
            Table newTable = new TableBuilder("NewTable")
                    .addColumn(new ColumnBuilder("ID", DataType.LONG)
                            .setAutoNumber(true))
                    .addColumn(new ColumnBuilder("TextField", DataType.TEXT))
                    .addIndex(new IndexBuilder(IndexBuilder.PRIMARY_KEY_NAME)
                            .addColumns("ID").setPrimaryKey())
                    .toTable(db);

            // insert a row into the table
            newTable.addRow(Column.AUTO_NUMBER, "This is a new row.");

            db.close();
        } catch (Exception e) {
            e.printStackTrace(System.err);
        }

    }

}

2016-02-04 更新： 代码改进。非常感谢 Dell Boomi 的 James 提供的帮助！

使用 Jackcess 和 JCIFS 来操作 SMB 共享上的 Access 数据库

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