Export DDL to F:/ebooks/PG/520 lab/workspace ... F:/ebooks/PG/520 lab/workspace
Feb 01, 2016 6:47:34 PM org.hibernate.annotations.common.Version <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.2.Final}
Feb 01, 2016 6:47:34 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.2.21.Final}
Feb 01, 2016 6:47:34 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Feb 01, 2016 6:47:34 PM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
Feb 01, 2016 6:47:34 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect
Feb 01, 2016 6:47:34 PM org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: HHH000227: Running hbm2ddl schema export
Feb 01, 2016 6:47:34 PM org.hibernate.tool.hbm2ddl.SchemaExport execute
ERROR: HHH000231: Schema export unsuccessful
java.io.FileNotFoundException: F:\ebooks\PG\520 lab\workspace (Access is denied)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:110)
    at java.io.FileWriter.<init>(FileWriter.java:63)
    at org.hibernate.tool.hbm2ddl.FileExporter.<init>(FileExporter.java:36)
    at org.hibernate.tool.hbm2ddl.SchemaExport.execute(SchemaExport.java:365)
    at org.hibernate.tool.hbm2ddl.SchemaExport.execute(SchemaExport.java:323)
    at gapp.util.Hbm2ddl.main(Hbm2ddl.java:43)

Feb 01, 2016 6:47:34 PM org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: HHH000230: Schema export complete
Done.

When I run Hbm2ddl.java I am etting this error

checked the versions still the problem persists

You need to specify a file name. It looks like you specified a folder name.