我有一个存储火车座位预订系统数据的应用程序。
我正在使用 apache poi 读取数据并将其写入 Excel 文件。
Apache-poi 版本：5.2.2、5.2.3（从此链接下载）
//import org.apache.commons.lang3.ArrayUtils;
//package org.apache.commons.lang3;
package com.company;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.*;
public class Train
{
public static void main(String[] args) throws IOException {
int coachNumber = 0;
String roomName = null; // This will be the coach assigned to the customer
String choice = "";
String deleteCustomer;
int foundCustomerIndex = 0;
String[] customer = new String[11];
Scanner input = new Scanner(System.in);
//initialise
initialise(customer); //better to initialise in a procedure
while (!choice.equals("Q")) {
System.out.println("\n===== Menu =====" +
"\nA - Add Customers\n" +
"V - View All Coaches\n" +
"E - Display Empty Coaches\n" +
"D - Delete Customer From Coach\n" +
"F - Find Coach From Customer name\n" +
"S - Store program data into file\n" +
"L - Load program data from file\n" +
"O - View guests Ordered alphabetically by name\n" +
"Q - To exit\n" +
"================\n");
System.out.print("\nEnter a letter from above to proceed: ");
try {
choice = input.next();
}
catch (Exception e) {
System.out.println("Exception Handled.\nEnter valid input");
System.out.print("\nEnter a letter from above to proceed: ");
choice = input.next();
}
switch (choice.toUpperCase(Locale.ROOT)) {
// Case A -->
//Add Customer
case "A":
System.out.println("\n===== Add Customer =====\n");
System.out.println("Enter coach number (0-9) or 10 to stop:");
coachNumber = input.nextInt();
System.out.println("Enter your name for coach " + coachNumber + " :");
roomName = input.next();
customer[coachNumber] = roomName;
break;
// case V
// View All coaches
case "V":
System.out.println("\n===== View All coaches =====\n");
for (int x = 0; x < 10; x++) {
System.out.println("coach " + x + " occupied by " + customer[x]);
}
break;
// Case E -->
// Display Empty coaches
case "E":
System.out.println("\n===== Empty Coaches =====\n");
for (int x = 0; x < 10; x++) {
if (customer[x].equals("e")) {
System.out.println("coach " + x + " is empty");
}
}
break;
// Case D -->
// Delete a Customer from Coach
case "D":
System.out.println("\n===== Delete a Customer from Coach =====\n");
System.out.println("Enter customer name to delete: ");
deleteCustomer = input.next();
for (int i = 0; i < 10; i++) {
if (customer[i] == "e")
continue;
else {
customer[i] = "e";
roomName = "e";
System.out.println("\nCustomer " + deleteCustomer + " has been removed!");
break;
}
}
break;
// Case F -->
// Find Coach from customer name
case "F":
System.out.println("\n===== Find Coach from customer name =====\n");
String findCustomerName;
System.out.println("Find Customer Name: ");
findCustomerName = input.next();
for (int i = 0; i < customer.length; i++) {
if (findCustomerName.equals(customer[i])) {
System.out.println("Customer Found.\nCabin Number: " + i);
break;
}
}
break;
// Case S -->
// Store/ Write program data into file
case "S":
System.out.println("\n===== Store program data into file =====\n");
XSSFWorkbook workbook = new XSSFWorkbook(); //Empty workbook
XSSFSheet sheet = workbook.createSheet("Emp Info"); //Empty sheet
// Adding data to the sheet
Object empdata[][] = {
{"coachNo.", "name"}, //Header
{coachNumber, roomName},
};
// Using normal loop
int rows = empdata.length;
int cols = empdata[0].length;
// System.out.println(rows); //4 rows
// System.out.println(cols); //3 columns
for (int r = 0; r < rows; r++) //rows
{
XSSFRow row = sheet.createRow(r); //Create new row
for (int c = 0; c < cols; c++) //cells
{
XSSFCell cell = row.createCell(c); //Creating cell
Object value = empdata[r][c]; //cell location
if (value instanceof String)
cell.setCellValue((String) value);
if (value instanceof Integer)
cell.setCellValue((Integer) value);
if (value instanceof Boolean)
cell.setCellValue((Boolean) value);
}
}
String filePath = ".\\writeCustomers.xlsx"; //Save location for the excel file
FileOutputStream outstream = new FileOutputStream(filePath);
workbook.write(outstream);
outstream.close();
System.out.println("\nFile has been written successfully.\nFilename: writeCustomers.xlsx ...");
break;
// Case L -->
// Load/ Read program data from file
case "L":
System.out.println("\n===== Load program data from file =====\n");
String excelFilePath = ".\\writeCustomers.xlsx"; //Read file location
FileInputStream inputStream = new FileInputStream(excelFilePath); //File opens in read mode
XSSFWorkbook readWorkbook = new XSSFWorkbook(inputStream); //Getting workbook from poi
XSSFSheet readSheet = readWorkbook.getSheet("Emp Info"); // Sheet Name
// With iterators
Iterator iterator = readSheet.iterator(); // To capture all the data into iterator
while (iterator.hasNext()) // Checking the iterator has the next record
{
XSSFRow row = (XSSFRow) iterator.next(); //Row iterator
Iterator cellIterator = row.cellIterator(); //iterate all the cells
while (cellIterator.hasNext()) //Checking cell present or not
{
XSSFCell cell = (XSSFCell) cellIterator.next();
switch (cell.getCellType()) //Type of the cell
{
case STRING: //if cell type string
System.out.print(cell.getRichStringCellValue());
break;
case NUMERIC:
System.out.print(cell.getNumericCellValue());
break;
case BOOLEAN:
System.out.print(cell.getBooleanCellValue());
break;
}
System.out.print(" | ");
}
System.out.println();
}
break;
// Case O -->
// View guest name in alphabetic order
case "O":
System.out.println("\n===== View guest name in alphabetic order =====\n");
//customer is the array name
for (int i = 0; i < customer.length - 1; i++) {
for (int j = i + 1; j < customer.length; j++) {
if (customer[i].compareTo(customer[j]) > 0) {
String temp = customer[i];
customer[i] = customer[j];
customer[j] = temp;
}
}
}
System.out.println(Arrays.toString(customer));
break;
// Case Q -->
// Exit
case "Q":
System.out.println("\nYou have exitted the program.");
break;
}
}
}
private static String[] sortArray(String[] customer)
{
for (int i = 0; i<10; i++)
{
for(int j = i + 1; j > 0; j--)
{
if(customer[j].compareTo(customer[j-1]) < 0)
{
String temp = customer[j];
customer[j] = customer[j-1];
customer[j-1] = temp;
}
}
}
return customer;
}
// to view all coaches with e [empty]
private static void initialise(String hotelRef[]) {
for (int x = 0; x < 10; x++) hotelRef[x] = "e";
System.out.println("initilise ");
}
}
Excel文件用于
case "S": case "L":所以问题出在依赖关系上。我尚未将所需的依赖项正确添加到我希望依赖项起作用的项目中。
如何添加依赖（IntelliJ Idea）
文件 -> 项目结构 -> 模块 -> 依赖项