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JDBC Driver for the Firebird RDBMS
There is a newer version: 6.0.0-beta-1
/*
 * Firebird Open Source JavaEE Connector - JDBC Driver
 *
 * Distributable under LGPL license.
 * You may obtain a copy of the License at http://www.gnu.org/copyleft/lgpl.html
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * LGPL License for more details.
 *
 * This file was created by members of the firebird development team.
 * All individual contributions remain the Copyright (C) of those
 * individuals.  Contributors to this file are either listed here or
 * can be obtained from a source control history command.
 *
 * All rights reserved.
 */
package org.firebirdsql.jdbc.field;

import org.firebirdsql.encodings.Encoding;
import org.firebirdsql.gds.ng.fields.FieldDescriptor;
import org.firebirdsql.jdbc.FBBlob;
import org.firebirdsql.jdbc.FBClob;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.sql.Blob;
import java.sql.Clob;
import java.sql.SQLException;

/**
 * This is Blob-based implementation of {@link FBStringField}. It should be used
 * for fields declared in database as BLOB SUB_TYPE 1. This 
 * implementation provides all conversion routines {@link FBStringField} has.
 * 
 * @author Roman Rokytskyy
 * @author Mark Rotteveel
 */
public class FBLongVarCharField extends FBStringField implements FBFlushableField {

    // TODO Reduce duplication with FBBlobField

    private static final int BUFF_SIZE = 4096;
    
    private FBBlob blob;
    private boolean blobExplicitNull;

    // Rather then hold cached data in the XSQLDAVar we will hold it in here.
    private long length;
    private byte[] bytes;
    private InputStream binaryStream;
    private Reader characterStream;

    FBLongVarCharField(FieldDescriptor fieldDescriptor, FieldDataProvider dataProvider, int requiredType)
            throws SQLException {
        super(fieldDescriptor, dataProvider, requiredType);
    }

    @Override
    public void close() throws SQLException {
        try {
            if (blob != null) blob.free();
        } finally {
            // forget this blob instance, resource waste
            // but simplifies our life. BLOB handle will be
            // released by a server automatically later

            blob = null;
            blobExplicitNull = false;
            bytes = null;
            binaryStream = null;
            characterStream = null;
            length = 0;
        }
    }

    @Override
    public Blob getBlob() throws SQLException {
        if (blob != null) return blob;
        if (isNull()) return null;

        blob = new FBBlob(gdsHelper, getDatatypeCoder().decodeLong(getFieldData()));
        return blob;
    }

    @Override
    public Clob getClob() throws SQLException {
    	FBBlob blob = (FBBlob) getBlob();
    	if (blob == null) return null;
    	return new FBClob(blob);
    }

    @Override
    public InputStream getBinaryStream() throws SQLException {
        Blob blob = getBlob();
        if (blob == null) return null;
        return blob.getBinaryStream();
    }

    @Override
    public byte[] getBytes() throws SQLException {
        final Blob blob = getBlob();
        if (blob == null) return null;

        try (final InputStream in = blob.getBinaryStream()) {
            if (in == null) return null;
            final ByteArrayOutputStream bout = new ByteArrayOutputStream();

            final byte[] buff = new byte[BUFF_SIZE];
            int counter;
            while((counter = in.read(buff)) != -1) {
                bout.write(buff, 0, counter);
            }
            return bout.toByteArray();
        } catch(IOException ioex) {
            throw new TypeConversionException(BYTES_CONVERSION_ERROR + " " + ioex.getMessage());
        }
    }

    @Override
    public byte[] getCachedData() throws SQLException {
        if (isNull()) return bytes;
        return getBytes();
    }

    @Override
    public FBFlushableField.CachedObject getCachedObject() throws SQLException {
        if (isNull()) {
            return new CachedObject(bytes, binaryStream, characterStream, length);
        }

        final byte[] bytes = getBytes();
        return new CachedObject(bytes, null, null, bytes.length);
    }

    @Override
    public void setCachedObject(FBFlushableField.CachedObject cachedObject) throws SQLException {
        // setNull() to reset field to empty state
        setNull();
        bytes = cachedObject.bytes;
        binaryStream = cachedObject.binaryStream;
        characterStream = cachedObject.characterStream;
        length = cachedObject.length;
        blobExplicitNull = bytes == null && binaryStream == null && characterStream == null;
    }

    @Override
    public String getString() throws SQLException {
        byte[] data = getBytes();
        if (data == null) return null;
        
        return getDatatypeCoder().decodeString(data);
    }

    @Override
    public void setBlob(FBBlob blob) throws SQLException {
        // setNull() to reset field to empty state
        setNull();
        setFieldData(getDatatypeCoder().encodeLong(blob.getBlobId()));
        this.blob = blob;
        blobExplicitNull = false;
    }

    @Override
    public void setClob(FBClob clob) throws SQLException {
    	FBBlob blob = clob.getWrappedBlob();
    	setBlob(blob);
    }

    @Override
    protected void setCharacterStreamInternal(Reader in, long length) throws SQLException {
        // setNull() to reset field to empty state
        setNull();
        if (in != null) {
            this.characterStream = in;
            this.length = length;
            blobExplicitNull = false;
        }
    }

    @Override
    public void setString(String value) throws SQLException {
        // setNull() to reset field to empty state
        setNull();
        if (value != null) {
            setBytes(getDatatypeCoder().encodeString(value));
        }
    }

    @Override
    public void setBytes(byte[] value) throws SQLException {
        // setNull() to reset field to empty state
        setNull();
        if (value != null) {
            this.bytes = value;
            this.length = value.length;
            blobExplicitNull = false;
        }
    }

    @Override
    protected void setBinaryStreamInternal(InputStream in, long length) throws SQLException {
        // setNull() to reset field to empty state
        setNull();
        if (in != null) {
            this.binaryStream = in;
            this.length = length;
            blobExplicitNull = false;
        }
    }

    @Override
    public void flushCachedData() throws SQLException {
        if (binaryStream != null) {
            copyBinaryStream(this.binaryStream, this.length);
        } else if (characterStream != null) {
            copyCharacterStream(characterStream, length);
        } else if (bytes != null) {
            copyBytes(bytes, (int) length);
        } else if (blob == null && blobExplicitNull) {
            setNull();
        }
        
        this.characterStream = null;
        this.binaryStream = null;
        this.bytes = null;
        this.length = 0;
    }

    @Override
    public void setNull() {
        super.setNull();
        try {
            if (blob != null) blob.free();
        } catch (SQLException e) {
            //ignore
        } finally {
            blob = null;
            blobExplicitNull = true;
            binaryStream = null;
            characterStream = null;
            bytes = null;
            length = 0;
        }
    }
    
    private void copyBinaryStream(InputStream in, long length) throws SQLException {
        FBBlob blob =  new FBBlob(gdsHelper);
        blob.copyStream(in, length);
        setFieldData(getDatatypeCoder().encodeLong(blob.getBlobId()));
        blobExplicitNull = false;
    }

    private void copyCharacterStream(Reader in, long length) throws SQLException {
        FBBlob blob =  new FBBlob(gdsHelper);
        // TODO Push this down into FBBlob?
        Encoding encoding = getDatatypeCoder().getEncoding();
        blob.copyCharacterStream(in, length, encoding);
        setFieldData(getDatatypeCoder().encodeLong(blob.getBlobId()));
        blobExplicitNull = false;
    }
    
    private void copyBytes(byte[] bytes, int length) throws SQLException {
        FBBlob blob = new FBBlob(gdsHelper);
        blob.copyBytes(bytes, 0, length);
        setFieldData(getDatatypeCoder().encodeLong(blob.getBlobId()));
        blobExplicitNull = false;
    }

}