如何使用spring boot从excel中读取数据并将其存储在mongodb中

Question

I want to develop a code where I can read data from excel and store the data in mongodb using spring mvc spring boot. Also, in my project we have separated the database layer, So I am consuming the mongodb API by URL. Mongodb is hosted on AWS.

I have tried reading the excel file but unable to store them in mongodb

Answer 1

You have provided very less data in question which will make it difficult for us to help you however here is my attempt....

To read data from excel folloing code changes needs to be done in your code base.

Add the following dependancies to your pom.xml file

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.17</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.17</version>
</dependency>

If you are usning gradle the ad following to build.gradle file

compile "org.apache.poi:poi:3.17"
compile "org.apache.poi:poi-ooxml:3.17"

Coming directly to the business portion of your question write following class

import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.*;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;

public class ExcelReader {
    public static final String SAMPLE_XLSX_FILE_PATH = "./sample-xlsx-file.xlsx";

    public static void main(String[] args) throws IOException, InvalidFormatException {

        // Creating a Workbook from an Excel file (.xls or .xlsx)
        Workbook workbook = WorkbookFactory.create(new File(SAMPLE_XLSX_FILE_PATH));

        // Retrieving the number of sheets in the Workbook
        System.out.println("Workbook has " + workbook.getNumberOfSheets() + " Sheets : ");

        /*
           =============================================================
           Iterating over all the sheets in the workbook (Multiple ways)
           =============================================================
        */

        // 1. You can obtain a sheetIterator and iterate over it
        Iterator<Sheet> sheetIterator = workbook.sheetIterator();
        System.out.println("Retrieving Sheets using Iterator");
        while (sheetIterator.hasNext()) {
            Sheet sheet = sheetIterator.next();
            System.out.println("=> " + sheet.getSheetName());
        }

        // 2. Or you can use a for-each loop
        System.out.println("Retrieving Sheets using for-each loop");
        for(Sheet sheet: workbook) {
            System.out.println("=> " + sheet.getSheetName());
        }

        // 3. Or you can use a Java 8 forEach with lambda
        System.out.println("Retrieving Sheets using Java 8 forEach with lambda");
        workbook.forEach(sheet -> {
            System.out.println("=> " + sheet.getSheetName());
        });

        /*
           ==================================================================
           Iterating over all the rows and columns in a Sheet (Multiple ways)
           ==================================================================
        */

        // Getting the Sheet at index zero
        Sheet sheet = workbook.getSheetAt(0);

        // Create a DataFormatter to format and get each cell's value as String
        DataFormatter dataFormatter = new DataFormatter();

        // 1. You can obtain a rowIterator and columnIterator and iterate over them
        System.out.println("\n\nIterating over Rows and Columns using Iterator\n");
        Iterator<Row> rowIterator = sheet.rowIterator();
        while (rowIterator.hasNext()) {
            Row row = rowIterator.next();

            // Now let's iterate over the columns of the current row
            Iterator<Cell> cellIterator = row.cellIterator();

            while (cellIterator.hasNext()) {
                Cell cell = cellIterator.next();
                String cellValue = dataFormatter.formatCellValue(cell);
                System.out.print(cellValue + "\t");
            }
            System.out.println();
        }

        // 2. Or you can use a for-each loop to iterate over the rows and columns
        System.out.println("\n\nIterating over Rows and Columns using for-each loop\n");
        for (Row row: sheet) {
            for(Cell cell: row) {
                String cellValue = dataFormatter.formatCellValue(cell);
                System.out.print(cellValue + "\t");
            }
            System.out.println();
        }

        // 3. Or you can use Java 8 forEach loop with lambda
        System.out.println("\n\nIterating over Rows and Columns using Java 8 forEach with lambda\n");
        sheet.forEach(row -> {
            row.forEach(cell -> {
                String cellValue = dataFormatter.formatCellValue(cell);
                System.out.print(cellValue + "\t");
            });
            System.out.println();
        });

        // Closing the workbook
        workbook.close();
    }
}

Retrieving Cell values by CellType

private static void printCellValue(Cell cell) {
    switch (cell.getCellTypeEnum()) {
        case BOOLEAN:
            System.out.print(cell.getBooleanCellValue());
            break;
        case STRING:
            System.out.print(cell.getRichStringCellValue().getString());
            break;
        case NUMERIC:
            if (DateUtil.isCellDateFormatted(cell)) {
                System.out.print(cell.getDateCellValue());
            } else {
                System.out.print(cell.getNumericCellValue());
            }
            break;
        case FORMULA:
            System.out.print(cell.getCellFormula());
            break;
        case BLANK:
            System.out.print("");
            break;
        default:
            System.out.print("");
    }

    System.out.print("\t");
}

Simply call like that

sheet.forEach(row -> {
    row.forEach(cell -> {
        printCellValue(cell);
    });
    System.out.println();
});

To help us you in adding the same to mongoDB you have to provide us some more info. Comment if you need any help in above code.