java.lang.ClassCastException: oracle.sql.BLOB cannot be cast to oracle.sql.BLOB

问题

I have problem retrieving a blob object from oracle DB to java API with jdbc. The problem is when I execute a Collable statement with a function from the db which return me a blob field this exception is thrown on the line :

tempBlob = (oracle.sql.BLOB)cstmt.getObject(1);

with this error message :

java.lang.ClassCastException: oracle.sql.BLOB cannot be cast to oracle.sql.BLOB. 

The object which I get from the DB is a instance of oracle.sql.BLOB. The tempBlob variable is a object oracle.sql.BLOB. Where is the problem?

回答1:

Two oracle jar files may be in your classpath. Please remove one jar and deploy again.

回答2:

Sometime one JAR is in the application classpath and another is in the application server classpath (eg.: in Tomcat $CATALINA_HOME/lib)

回答3:

Dont Cast again like:

BLOB tempBlob = (oracle.sql.BLOB)cstmt.getObject(1);

Solution :

OutputStream outstrm =(rs.getBlob(1)).setBinaryStream(1L); 

回答4:

I got this error while generating a jasper report.

I replaced the class=oracle.jdbc.OracleBlob with class=java.sql.Blob in the jrxml file of that report. It worked for me.

来源：https://stackoverflow.com/questions/11411306/java-lang-classcastexception-oracle-sql-blob-cannot-be-cast-to-oracle-sql-blob