Problem Statement
In this article, we are showcasing how to convert a base64 string into a file attachment to be conveniently downloaded as an attachment.
Solution
Figure 1 : Sample showcase form design to convert Base64 string into a file upload attachment
Reading Base64 string from form data and saving it as file attachment in File Upload field
import java.io.File;
import java.io.IOException;
import org.apache.commons.io.FileUtils;
import org.joget.apps.form.service.FileUtil;
import org.joget.commons.util.SetupManager;
import org.joget.commons.util.LogUtil;
import java.util.Base64;
import org.joget.apps.app.model.AppDefinition;
import org.joget.apps.app.service.AppService;
import org.joget.apps.app.service.AppUtil;
import org.joget.apps.form.model.FormRow;
import org.joget.apps.form.model.FormRowSet;
import org.springframework.context.ApplicationContext;
String formDefId = "request";
String fileName = "#form.request.file_name#";
String tableName = "request";
String id = "#form.request.id#";
String formUploadField = "attachment";
//generate file from base64
String base64String = "#form.request.data#";
byte[] data = Base64.getDecoder().decode(base64String);
//store pdf
String path = FileUtil.getUploadPath(tableName, id);
final File file = new File(path + fileName);
try {
//save the file into default folder
FileUtil.storeFile(file, tableName, tableName);
FileUtils.writeByteArrayToFile(file, data);
//file saved successfully, update the form record to store the file name
ApplicationContext ac = AppUtil.getApplicationContext();
AppService appService = (AppService) ac.getBean("appService");
AppDefinition appDef = AppUtil.getCurrentAppDefinition();
FormRowSet set = appService.loadFormData(appDef.getAppId(), appDef.getVersion().toString(), formDefId, id);
FormRow row = set.get(0);
row.put(formUploadField, fileName);
set.remove(0);
set.add(0, row);
appService.storeFormData(appDef.getAppId(), appDef.getVersion().toString(), formDefId, set, id);
} catch (IOException ex) {
LogUtil.error("base64ToPDF App", ex, "Cannot generate file");
}
Download Showcase App
