如何在 olingo v2 中处理 BLOB 和 CLOB？

Question

Here there is pseudocode about how to handle BLOB and CLOB in olingo jpa. I added the needed imports to the pseudocode:

package me;

import java.sql.Blob;
import java.sql.Clob;
import java.sql.SQLException;

import javax.sql.rowset.serial.SerialException;

import org.apache.olingo.odata2.jpa.processor.api.OnJPAWriteContent;
import org.apache.olingo.odata2.jpa.processor.api.exception.ODataJPARuntimeException;

public class OnDBWriteContent implements OnJPAWriteContent {

    @Override
    public Blob getJPABlob(byte[] binaryData) throws ODataJPARuntimeException {
        try {
            return new JDBCBlob(binaryData);
        } catch (SerialException e) {
            ODataJPARuntimeException.throwException(ODataJPARuntimeException.INNER_EXCEPTION, e);
        } catch (SQLException e) {
            ODataJPARuntimeException.throwException(ODataJPARuntimeException.INNER_EXCEPTION, e);
        }
        return null;
    }

    @Override
    public Clob getJPAClob(char[] characterData) throws ODataJPARuntimeException {
        try {
            return new JDBCClob(new String(characterData));
        } catch (SQLException e) {
            ODataJPARuntimeException.throwException(ODataJPARuntimeException.INNER_EXCEPTION, e);
        }
        return null;
    }
}

the only problem is I couldn't find any implementation for JDBCBlob and JDBCClob . Any suggestion about how can I implement them or use some classes?

Answer 1

If You are using MySQL it requires an additional ExceptionInterceptor along with the Blob Implementation. You can have a custom implementation of ExceptionInterceptor and use it to initialise the Blob field.

The code to achieve it would be as follows

import java.sql.Blob;
import java.sql.Clob;
import java.util.Properties;

import org.apache.olingo.odata2.jpa.processor.api.OnJPAWriteContent;
import org.apache.olingo.odata2.jpa.processor.api.exception.ODataJPARuntimeException;

import com.mysql.cj.exceptions.ExceptionInterceptor;
import com.mysql.cj.log.Log;

public class CustomOnJPAWriteContent implements OnJPAWriteContent {

    @Override
    public Blob getJPABlob(byte[] binaryData) throws ODataJPARuntimeException {
        return new com.mysql.cj.jdbc.Blob(binaryData, exceptionInterceptor);
    }

    @Override
    public Clob getJPAClob(char[] characterData) throws ODataJPARuntimeException {
        
        return new com.mysql.cj.jdbc.Clob(new String(characterData), exceptionInterceptor);

    }

    ExceptionInterceptor exceptionInterceptor = new ExceptionInterceptor() {

        @Override
        public Exception interceptException(Exception sqlEx) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public ExceptionInterceptor init(Properties props, Log log) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public void destroy() {
            // TODO Auto-generated method stub

        }
    };

}