如何在olingov2中处理BLOB和CLOB

Question

这里有一个关于如何在olingojpa中处理BLOB和CLOB的伪代码。我在伪代码中添加了所需的导入：

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;
}
}

唯一的问题是我找不到CCD_ 1和CCD_。关于如何实现它们或使用一些类，有什么建议吗？

Answer 1

如果使用MySQL，则需要额外的ExceptionInterceptor以及Blob实现。您可以拥有ExceptionInterceptor的自定义实现，并使用它初始化Blob字段。

实现它的代码如下

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
}
};
}