You can handle loading the excel file content by writing Java code using Apache POI library (https://poi.apache.org/). The library is developed for working with MS office application data including Excel.
I have recently created the application based on the technology that will help you to load Excel files to the Postgres database. The application is available under http://www.abespalov.com/. The application is tested only for Windows, but should work for Linux as well.
The application automatically creates necessary tables with the same columns as in the Excel files and populate the tables with content. You can export several files in parallel. You can skip the step to convert the files into the CSV format. The application handles the xls and xlsx formats.
Overall application stages are :
{
fileExtension = FilenameUtils.getExtension(inputSheetFile.getName());
if (fileExtension.equalsIgnoreCase("xlsx")) {
workbook = createWorkbook(openOPCPackage(inputSheetFile));
} else {
workbook =
createWorkbook(openNPOIFSFileSystemPackage(inputSheetFile));
}
sheet = workbook.getSheetAt(0);
}
{
Iterator<Row> rowIterator = InitInputFilesImpl.sheet.rowIterator();
//skip a header
if (rowIterator.hasNext()) {
rowIterator.next();
}
while (rowIterator.hasNext()) {
Row row = (Row) rowIterator.next();
// inserting rows
}
}
Here you can find all Java code for the application created for exporting excel to Postgres (https://github.com/palych-piter/Excel2DB).