Spring Batch: How to load image files to PostgreSQL?-CodePudding

I need to load all files from the directory to the bytea field of PostgreSql database. File name contains the key value, i.e. "1.jpg". How can I achieve it with Spring Batch? I have some expirience with Spring Batch, but never worked with files and blob fields.

CodePudding user response：

You can design the type of your items as follows for example:

class FileItem {
   String name;
   byte[] content;
}

and use a ItemPreparedStatementSetter that sets the image content with PreparedStatement#setBytes. This custom prepared statement setter can be used with the JdbcBatchItemWriter.

CodePudding user response：

I resolved this problem by myself.

ImageDto:

public class ImageDto {
    private long id;
    private byte[] image;

    //getters and setters
    
}

ItemReader:

@Bean
public ItemReader<File> modelImageLargeReader() throws IOException {
    List<File> files =     Files.walk(Paths.get(appProperties.getSkiImagesLarge()))
            .filter(Files::isRegularFile)
            .map(Path::toFile)
            .collect(Collectors.toList());
    return new IteratorItemReader<>(files);
}

ItemProcessor:

@Bean
@StepScope
public ItemProcessor<File, ImageDto> modelImageProcessor() {
    return item -> {
        var imageDto = new ImageDto();
        var fName = item.getName();
        var index = fName.indexOf('.');
        var strId =  fName.substring(0, index);
        imageDto.setId(Long.valueOf(strId));
        imageDto.setImage(Files.readAllBytes(item.toPath()));
        return imageDto;
    };
}

ItemWriter:

@Bean
public ItemWriter<ImageDto> modelImageLargeWriter() {
    return new JdbcBatchItemWriterBuilder<ImageDto>()
            .dataSource(dataSource)
            .sql("update model set image_large = :image where id_model = :id")
            .beanMapped()
            .build();
}