spring-boot-starter-web-excel

Provides ability to upload and download excel file as list or stream of java objects.
Using streams permits to not keep all data in memory, but to process it line by line.
Uses Poiji2 as excel parser.

In your Maven/Gradle project, first add the corresponding dependency:

maven

<dependencies>
    <dependency>
        <groupId>io.github.vaa25</groupId>
        <artifactId>spring-boot-starter-web-excel</artifactId>
        <version>0.0.9</version>
    </dependency>
    <dependency>
        <groupId>io.github.vaa25</groupId>
        <artifactId>poiji2</artifactId>
        <version>1.3.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>5.0.0</version>
    </dependency>
</dependencies>

gradle

dependencies {
    implementation 'io.github.vaa25:spring-boot-starter-web-excel:0.0.9'
    implementation 'io.github.vaa25:poiji2:1.3.0'
    implementation 'org.apache.poi:poi-ooxml:5.0.0'
}

public class RowEntity{

    @ExcelCellName("column1")
    private Integer column1;

    @ExcelCellName("column2")
    private String column2;

}

To download file enough to send ExcelHttpFile as response from rest controller.
Accept request header must contain one of next values:

• application/vnd.openxmlformats-officedocument.spreadsheetml.sheet to get xlsx file

• application/vnd.ms-excel to get xls file

• text/csv to get csv file

import static io.github.vaa25.excel.ExcelFormat.Constants.*

@RestController
public class Controller{

    @GetMapping(value = "/download-from-list", produces = {XLSX_MEDIA_TYPE_VALUE, CSV_MEDIA_TYPE_VALUE, XLS_MEDIA_TYPE_VALUE})
    public ExcelHttpFile<RowEntity> downloadList(){

        List<RowEntity> content = getContent();
        return ExcelHttpFile.of("file_name", content, RowEntity.class);

    }

    @GetMapping(value = "/download-from-stream", produces = {XLSX_MEDIA_TYPE_VALUE, CSV_MEDIA_TYPE_VALUE, XLS_MEDIA_TYPE_VALUE})
    public ExcelHttpFile<RowEntity> downloadStream(){

        Stream<RowEntity> content = getContent();
        return ExcelHttpFile.of("file_name", content, RowEntity.class);

    }


}

To upload file enough to replace @RequestPart with @RequestExcelFile and receive List or Stream as data

import static org.springframework.http.MediaType.MULTIPART_FORM_DATA_VALUE;

@RestController
public class Controller{

    @PostMapping(value = "/upload-to-stream", consumes = MULTIPART_FORM_DATA_VALUE)
    public void uploadStream(@RequestExcelFile("fileToUpload") final Stream<RowEntity> data){
        ...
    }

    @PostMapping(value = "/upload-to-list", consumes = MULTIPART_FORM_DATA_VALUE)
    public void uploadList(@RequestExcelFile("fileToUpload") final List<RowEntity> data){
        ...
    }

}

Poiji options supported. You can redefine default options as bean. It will be used in all transformations if explicit options are absent.

import static io.github.vaa25.excel.RequestExcelFile.DEFAULT_EXCEL_OPTIONS_BEAN_NAME;

@Configuration
public class Config{

    @Bean(DEFAULT_EXCEL_OPTIONS_BEAN_NAME)
    public void defaultExcelOptions(){
        return PoijiOptions.PoijiOptionsBuilder.settings().preferNullOverDefault(true).build();
    }

}

Explicit options can be added as beans and used next way:

import static org.springframework.http.MediaType.MULTIPART_FORM_DATA_VALUE;

@RestController
public class Controller{

    @PostMapping(value = "/upload-to-stream", consumes = MULTIPART_FORM_DATA_VALUE)
    public void uploadStream(
        @RequestExcelFile(value = "fileToUpload", optionsBean = "uploadOptions") final Stream<RowEntity> data
    ){
        ...
    }

    @GetMapping(value = "/download-from-list", produces = {XLSX_MEDIA_TYPE_VALUE, CSV_MEDIA_TYPE_VALUE, XLS_MEDIA_TYPE_VALUE})
    public ExcelHttpFile<RowEntity> downloadList(){

        List<RowEntity> content = getContent();
        return ExcelHttpFile.of("file_name", content, RowEntity.class).setOptionsBean("downloadOptions");

    }

}

Options can be built dynamically for download:

import static org.springframework.http.MediaType.MULTIPART_FORM_DATA_VALUE;

@RestController
public class Controller{

    @GetMapping(value = "/download-from-list", produces = {XLSX_MEDIA_TYPE_VALUE, CSV_MEDIA_TYPE_VALUE, XLS_MEDIA_TYPE_VALUE})
    public ExcelHttpFile<RowEntity> downloadList(){

        List<RowEntity> content = getContent();
        return ExcelHttpFile.of("file_name", content, RowEntity.class).setOptions(buildOptions());

    }

    private PoijiOptions buildOptions(){

        return PoijiOptions.PoijiOptionsBuilder.settings().build();

    }

}

Options have next priority:

1. Dynamic options (for download only)

2. Bean options

3. Default options