问包org.apache.poi.ss.usermodel不存在

EN

C:\Users\User\eclipse-workspace\Calendar_v1\src\cal>javac ShiftSetting.java

ShiftSetting.java:7: error: package org.apache.poi.ss.usermodel does not exist
import org.apache.poi.ss.usermodel.Cell;
                                  ^
ShiftSetting.java:8: error: package org.apache.poi.ss.usermodel does not exist
import org.apache.poi.ss.usermodel.DataFormatter;
                                  ^
ShiftSetting.java:9: error: package org.apache.poi.ss.usermodel does not exist
import org.apache.poi.ss.usermodel.Row;
                                  ^
ShiftSetting.java:10: error: package org.apache.poi.xssf.usermodel does not exist
import org.apache.poi.xssf.usermodel.XSSFSheet;
                                    ^
ShiftSetting.java:11: error: package org.apache.poi.xssf.usermodel does not exist
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
                                    ^
ShiftSetting.java:21: error: cannot find symbol
                        XSSFWorkbook wb = new XSSFWorkbook(file);
                        ^
  symbol:   class XSSFWorkbook
  location: class ShiftSetting
ShiftSetting.java:21: error: cannot find symbol
                        XSSFWorkbook wb = new XSSFWorkbook(file);
                                              ^
  symbol:   class XSSFWorkbook
  location: class ShiftSetting
ShiftSetting.java:22: error: cannot find symbol
                        XSSFSheet sheet = wb.getSheetAt(0);
                        ^
  symbol:   class XSSFSheet
  location: class ShiftSetting
ShiftSetting.java:24: error: cannot find symbol
                        DataFormatter formatter = new DataFormatter();
                        ^
  symbol:   class DataFormatter
  location: class ShiftSetting
ShiftSetting.java:24: error: cannot find symbol
                        DataFormatter formatter = new DataFormatter();
                                                      ^
  symbol:   class DataFormatter
  location: class ShiftSetting
ShiftSetting.java:29: error: cannot find symbol
                                Row r = sheet.getRow(rowNum);
                                ^
  symbol:   class Row
  location: class ShiftSetting
ShiftSetting.java:32: error: cannot find symbol
                                        Cell cell = r.getCell(m);
                                        ^
  symbol:   class Cell
  location: class ShiftSetting
ShiftSetting.java:39: error: cannot find symbol
                                Row r = sheet.getRow(rowNum);
                                ^
  symbol:   class Row
  location: class ShiftSetting
ShiftSetting.java:43: error: cannot find symbol
                                        Cell cell = r.getCell(m);
                                        ^
  symbol:   class Cell
  location: class ShiftSetting
14 errors

 package cal;

import java.io.File;
import java.io.FileInputStream;
import java.util.ArrayList;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ShiftSetting {
    public static void main(String[] args) {
    // code
    }
}