how to read Excel file in Servlet?

Question

I am trying to read excel file using POI library.

try {

File file=new File("C:\\new.xls");
FileInputStream fin = new FileInputStream(file);

//Get the workbook instance for XLS file
HSSFWorkbook workbook = new HSSFWorkbook(fin);

//Get first sheet from the workbook
HSSFSheet sheet = workbook.getSheetAt(0);

    //Iterate through each rows from first sheet
Iterator<Row> rowIterator = sheet.iterator();
while(rowIterator.hasNext()) 
    {
    Row row = rowIterator.next();
    //For each row, iterate through each columns
    Iterator<Cell> cellIterator = row.cellIterator();
    while(cellIterator.hasNext()) 
        {
        Cell cell = cellIterator.next();
        switch(cell.getCellType()) 
            {
      case Cell.CELL_TYPE_BOOLEAN:
         System.out.print(cell.getBooleanCellValue() + "\t\t");
         break;
      case Cell.CELL_TYPE_NUMERIC:
         System.out.print(cell.getNumericCellValue() + "\t\t");
         break;
      case Cell.CELL_TYPE_STRING:
         System.out.print(cell.getRichStringCellValue() + "\t\t");
         break;
    }
        }
    System.out.println("");
   }
fin.close();
FileOutputStream out =new FileOutputStream(file);
workbook.write(out); 
out.close();
}

catch (FileNotFoundException e) 
{
 e.printStackTrace();
} 
catch (IOException e) 
{
 e.printStackTrace();
}

I wrote above code in simple Java project and it worked very fine. But whenever I am trying to write same code in Servlet , I am getting following errors.

* *exception

javax.servlet.ServletException: Servlet execution threw an exception

root cause

java.lang.NoClassDefFoundError: org/apache/poi/hssf/usermodel/HSSFWorkbook com.ReadExcel.read(ReadExcel.java:30) com.ServletDemo.doPost(ServletDemo.java:23)` javax.servlet.http.HttpServlet.service(HttpServlet.java:641) javax.servlet.http.HttpServlet.service(HttpServlet.java:722)**

Please tell me what to do in order to remove these errors.

Answer 1

the exception only tells you that it is not able to find the HSSFWorkbook anywhere (in your classpath)

org/apache/poi jar needs to be in the classpath -> add it.

Answer 2

将poi jar文件放在WEB-INF / lib文件夹中

Answer 3

Create a "Dynamic Web Project" in Eclipse.

Put your source files into the "src" folder of the new project.

Put poi-3.9.jar into this folder in your project: WebContent/WEB-INF/lib/poi-3.9.jar

Right-Click your project and select Build Path -> Configure Build Path... Select the tab "Libraries" and expand the node "Web App Libraries". Here you must see an entry for poi-3.9.jar. If not, there is something wrong with the project setup.

Test your servlet.