问题描述

这里有关于如何处理 BLOB 和 CLOB 的伪代码在 olingo jpa.我在伪代码中添加了所需的导入:

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;
    }
}

唯一的问题是我找不到 JDBCBlob 和 JDBCClob 的任何实现.关于如何实现它们或使用某些类的任何建议?

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?

推荐答案

如果您使用的是 MySQL，它需要一个额外的 ExceptionInterceptor 以及 Blob 实现.您可以自定义实现 ExceptionInterceptor 并使用它来初始化 Blob 字段.

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.

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

        }
    };

}

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