从Java-应用程序访问NFS-共享

Question

我正在尝试从CentOS应用程序中访问6.3系统上的NFS共享。我尝试过以下库，但两者都无法工作：

YaNFS

尝试用YaNFS访问NFS共享时，我遇到了一个带有ErrorCode 10001 (NFSERR_BADHANDLE)的NfsException。有时异常的文本会写成“陈旧的NFS文件句柄”。我的YaNFS代码是：

    public static void main(String[] args) {
    XFile xf = new XFile("nfs://192.168.1.10/nfs-share");

    nfsXFileExtensionAccessor nfsx =
        (nfsXFileExtensionAccessor)xf.getExtensionAccessor();

        if (! nfsx.loginPCNFSD("192.168.1.10", "rpx-nfs-user", "Test123!")) {
             System.out.println("login failed");
             return;
        }

        if (xf.canRead())
             System.out.println("Read permission OK");
        else
             System.out.println("No Read permission");

}

nfs-client-java

尝试用"nfs-client-java“初始化Nfs3对象时，我得到了如下所示的MountException：

com.emc.ecs.nfsclient.mount.MountException: mount failure, 
    server: 192.168.1.205, 
    export: /home/share, 
    nfs version: 3, 
    returned state: 13
at com.emc.ecs.nfsclient.nfs.nfs3.Nfs3.lookupRootHandle(Nfs3.java:359)

关于这一点，第13号州表示拒绝批准。

我可以通过挂载此共享从另一个CentOS-系统(授权访问此文件夹uid和gid)和Windows-系统(授权访问此文件夹登录和密码)访问此共享。

有没有人已经解决了这个问题？或者有人能帮我走得更远？

Answer 1

通过在共享上启用CIFS协议并使用旧的JCIFS实现来传输数据，解决了这个问题。

Answer 2

因此，您在注释中指出，需要特定用户的优先级才能访问文件，因此出现了“权限拒绝”错误。在YaNFS中，您需要查看nfsXFileExtensionAccessor才能发送用户名和密码，以便获得权限。下面是我从这个页面中提取的一个例子：https://docs.oracle.com/cd/E19455-01/806-1067/6jacl3e6g/index.html

import java.io.*;
import com.sun.xfile.*;
import com.sun.nfs.*;

public class nfslogin {

     public static void main(String av[])
     {
          try {
               XFile xf = new XFile(av[0]);
               com.sun.nfsXFileExtensionAccessor nfsx =
               (com.sun.nfsXFileExtensionAccessor)xf.getExtensionAccessor();

               if (! nfsx.loginPCNFSD("pcnfsdsrv", "bob", "-passwd-")) {
                    System.out.println("login failed");
                    return;
               }

               if (xf.canRead())
                    System.out.println("Read permission OK");
               else
                    System.out.println("No Read permission");

          } catch (Exception e) {
            System.out.println(e.toString());
            e.printStackTrace(System.out);
          }
     }
}

编辑

不，我认为您不应该在登录操作之前调用bind()。来自github上的XFile源代码：

 /*
 * Check that the file is open.
 * The open() method must be called before
 * any other methods in the Accessor.
 * This makes it easier for Accessors to
 * centralize initialization code in one place.
 */
private boolean bind() {
    if (bound)
        return true;

    bound = xfa.open(this, false, false);

    return bound;
}

由于bind()函数试图打开文件，它将始终失败，直到您进行身份验证。然后考虑一下来自github上的XFileExtensionAccessor代码的代码

/**
 * Sets the user's RPC credential from Login name and password.
 *
 * Every NFS request includes a "credential" that identifies the user.
 * An AUTH_SYS credential includes the user's UID and GID values.
 * These are determined from the user's login name (and password)
 * by the PCNFSD service that must be available on a local server.
 * Once the credential is set, it is assigned globally to all
 * future NFS XFile objects.
 * <p>
 * If this method is not called, a default credential is assigned
 * with a UID and GID of "nobody".
 *
 * @param  <code>host</code> The name of the host that runs the PCNFSD service.
 *   This does not have to be an NFS server.
 * @param <code>username</code> The user's login name.
 * @param <code>password</code> The user's password.
 *   This is obscured before transmission to the PCNFSD server.
 * @return true if the login succeeded, false otherwise.
 */
public boolean loginPCNFSD(String host, String username, String password) {
    return NfsConnect.getCred().fetchCred(host, username, password);
}

因此，loginPCNFSD()函数将全局设置XFile系统的凭据，直到您注销或使用新登录。在调用XFile.Bind()之前一定要调用它；