Java的如何一个ArrayList保存到一个文件 [英] Java how to save An arrayList to a file
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问题描述
您好，我有这个code和它要求用户输入的视频和客户ID，并将其添加到一个数组列表，称为员工如何将我保存的ArrayList到一个文件中，当完成并退出该程序？
进口的java.util.ArrayList;
进口java.util.Scanner中;
公共类驱动器{
公共静态最终诠释LISTCUSTOMERS = 1;
公共静态最终诠释LISTVIDEOS = 2;
公共静态最终诠释LISTHIRES = 3;
公共静态最终诠释HIRESTATISTICS = 4;
公共静态最终诠释HIREVIDEO = 5;
公共静态最终诠释RETURNVIDEO = 6;
公共静态最终诠释QUIT = 7;
公共静态最终整数默认= 0;
私有String [] menuText;
私有静态最终诠释MAXVIDEOS = 9;
私有静态最终诠释MAXCUSTOMERS = 5;
静态扫描仪SC =新的扫描仪（System.in）;
私人诠释的选择;
公众诠释MAXLENGTH = 50;
公共静态的ArrayList＆LT;＆租用GT; HireList =新的ArrayList＆LT;＆租用GT;（）;
公共静态视频[] =视频新视频[MAXVIDEOS]
公共静态客户[] =客户新客户[MAXCUSTOMERS]
公共静态的String []选项= {，客户名单，列表影片，列表聘用，服务统计，服务视频，返回视频，退出};
公共静态驱动MYMENU =新的驱动程序（选项，SC）;
公共静态布尔多=真;
公共静态INT选项= 0;
静态客户的客户; 公共静态无效的主要（字串[] args）{
initilisation（）;
runHireVideo（）;
}
公共驱动程序（的String [] menuText，扫描仪SC）{
this.menuText = menuText;
}
公众诠释getMenuSelection（）{
this.displayMenu（）;
this.selection = sc.nextInt（）;
如果（this.selection＆LT;默认|| this.menuText.length＆LT; this.selection）{
的System.out.println（您的选择是无效的 - 使用默认）;
this.selection =默认值;
}
返回this.selection;
}
公共无效displayMenu（）{
System.out.print（\\ nMicroVideo菜单：\\ n）;
对于（INT指数= 1;指数＆LT; menuText.length;指数++）
的System.out.println（索引+ + menuText [索引]。）;
System.out.print（输入选项：）;
}
公共静态无效runHireVideo（）{ 而（更多）{
选项= myMenu.getMenuSelection（）;
开关（选配件）{
案例LISTCUSTOMERS：
ListCustomers（）;
打破;
案例LISTVIDEOS：
ListVideos（）;
打破;
案例LISTHIRES：
ListHires（）;
打破;
案例HIRESTATISTICS：
HireStatistics（）;
打破;
案例HIREVIDEO：
HireVideo（）;
打破;
案例RETURNVIDEO：
ReturnVideo（）;
打破;
默认：
更多= FALSE;
的System.out.println（程序已退出）;
打破;
}
}
}
公共静态无效initilisation（）{
视频[0] =新的视频（140，黑客帝国，7.50，3）;
视频[1] =新的视频（141，终结者2，5.00，3）;
视频[2] =新的视频（142，怪物史莱克，5.00，10）;
视频[3] =新的视频（143，城堡，5.00，1）;
视频[4] =新的视频（146，音乐之声，1.00，23）;
视频[5] =新的视频（147，行星人猿，5.00，0）;
视频[6] =新的视频（148，碟中谍，1.00，15）;
视频[7] =新的视频（150，巴格达之夜，6.00，5）;
视频[8] =新的视频（151，指环王1的主，5.00，0）; 客户[0] =新客户（9902JI，英尼斯，0,43484001）;
客户[1] =新客户（8906RH，赫伯特，0,43484000）;
客户[2] =新客户（9012GT，特纳，0,43480009）;
客户[3] =新的客户（9012GS，斯帕克，0,43480007）;
客户[4] =新的客户（9012MV，瓦兰斯，0,43480008）;
}
公共静态无效ListCustomers（）{
System.out.printf（％ - 6S％-5S％6S \\ n，客户ID，客户名称，客户电话号码）;
的for（int i = 0; I＆LT; customers.length;我++）{
的System.out.println（客户[I]）;
}
}
公共静态无效ListVideos（）{
System.out.printf（％ - 8S％-17s％6S％6S \\ n，视频ID，VideoName，视频价格率，库存）;
的for（int i = 0; I＆LT; videos.length;我++）{
的System.out.println（视频[I]）;
}
}
公共静态无效ListHires（）{
System.out.printf（％s％s％S％s％S \\ n，HireID，卡斯特名，视频名称，天聘用，服务成本）;
对于（租用出租：HireList）{
串客户=客户[hire.getID（hire.getVideoID（））] getCustomerName（）;
字符串VIDEOID =视频[hire.getID（hire.getVideoID（））]的getTitle（）。
双DailyRate =影片[hire.getID（hire.getVideoID（））]的getRate（）* hire.getDaysHired（）;
System.out.printf（％D％s％S％D％1.2F \\ n，hire.getHireID（），客户，VIDEOID，hire.getDaysHired（），DailyRate）;
}
}
公共静态无效HireStatistics（）{
System.out.printf（％s％s％S \\ n，视频ID，视频名称，天聘请）;
对于（租用出租：HireList）{
字符串VIDEOID =视频[hire.getID（hire.getVideoID（））]的getTitle（）。
System.out.printf（％s％S％d个\\ N，hire.getVideoID（），VIDEOID，hire.getDaysHired（））;
}
}
公共静态无效HireVideo（）{
诠释计数= 0;
而（计数== 0）{
INT hireID = 1000 + HireList.size（）+ 1;
的System.out.println（输入客户ID）;
字符串的customerID =9902JI;
的System.out.println（输入视频ID）;
字符串VIDEOID =140;
的System.out.println（输入天聘用）;
INT daysHired = 4;
的System.out.println（输入另一个租用[Y / N]？）;
String是= sc.next（）;
如果（Yes.equals（Y））{
计数= 0;
}
否则如果（Yes.equals（N））{
数= 1;
}
HireList.add（新员工（hireID，的customerID，VIDEOID，daysHired，0））;
} }
公共静态无效ReturnVideo（）{
的System.out.println（输入客户ID）;
字符串的customerID =9902JI;
的System.out.println（输入视频ID）;
字符串VIDEOID =140; 的for（int i = 0; I＆LT; HireList.size（）;我++）{
如果（HireList.get（ⅰ）.getCustomerID（）。等于（的customerID））{
HireList.remove（ⅰ）;
}
}
为（中间体二= 0; II蛋白酶HireList.size（）;ⅱ++）{
如果（HireList.get（II）.getVideoID（）。等于（VIDEOID））{
HireList.remove（二）;
}
}
的System.out.println（已删除+的customerID）;
} }
解决方案
最简单的方法，如前面提到的，那就是只要给每个成员保存在一个文本文件，并与扫描仪的对象（的 http://docs.oracle.com/javase/7/docs/api /java/util/Scanner.html ）。
如果你是关心如何写入一个文本文件，我建议阅读这篇文章：的 http://www.mkyong.com/java/how-to-write-to-file-in-java-bufferedwriter-example/
这也解释了如何使用FileWriter对象。
另一种选择是让驱动程序实现serialisable接口，这样可以让你存储整个驱动程序对象在一系列字节，但这是稍微复杂一些。系列化上一个体面的教程可以在这里找到：
http://www.tutorialspoint.com/java/java_serialization.htm
hello i have this code and it asks the user to enter a video and customer id and adds it to an array list called hires how would i save that arraylist to a file when the are finished and quit this program?
import java.util.ArrayList;
import java.util.Scanner;
public class Driver {
public static final int LISTCUSTOMERS = 1;
public static final int LISTVIDEOS = 2;
public static final int LISTHIRES = 3;
public static final int HIRESTATISTICS = 4;
public static final int HIREVIDEO = 5;
public static final int RETURNVIDEO = 6;
public static final int QUIT = 7;
public final static int DEFAULT = 0;
private String[] menuText;
private static final int MAXVIDEOS = 9;
private static final int MAXCUSTOMERS = 5;
static Scanner sc = new Scanner(System.in);
private int selection;
public int MAXLENGTH = 50;
public static ArrayList<Hire>HireList = new ArrayList<Hire>();
public static Video[]videos= new Video[MAXVIDEOS];
public static Customer [] customers = new Customer[MAXCUSTOMERS];
public static String [] options = {"","List Customers", "List Videos", "List Hires", "Hire Statistics", "Hire Video", "Return Video", "Quit"};
public static Driver myMenu = new Driver (options, sc);
public static boolean more = true;
public static int option = 0;
static Customer customer;
public static void main (String [] args){
initilisation();
runHireVideo();
}
public Driver (String[] menuText, Scanner sc){
this.menuText = menuText;
}
public int getMenuSelection(){
this.displayMenu();
this.selection = sc.nextInt();
if(this.selection < DEFAULT || this.menuText.length<this.selection){
System.out.println("Your selection was invalid - using default");
this.selection = DEFAULT;
}
return this.selection;
}
public void displayMenu(){
System.out.print("\nMicroVideo Menu: \n");
for (int index = 1; index < menuText.length; index++)
System.out.println(index + ". "+ menuText [index]);
System.out.print("Enter option: ");
}
public static void runHireVideo(){
while (more){
option = myMenu.getMenuSelection();
switch(option){
case LISTCUSTOMERS:
ListCustomers();
break;
case LISTVIDEOS:
ListVideos();
break;
case LISTHIRES:
ListHires();
break;
case HIRESTATISTICS:
HireStatistics();
break;
case HIREVIDEO:
HireVideo();
break;
case RETURNVIDEO:
ReturnVideo();
break;
default:
more = false;
System.out.println("Program Exited");
break;
}
}
}
public static void initilisation(){
videos[0]=new Video("140","The Matrix ", 7.50, 3);
videos[1]=new Video("141", "Terminator 2 ", 5.00, 3);
videos[2]=new Video("142", "Shrek ", 5.00, 10);
videos[3]=new Video("143", "The Castle ", 5.00, 1);
videos[4]=new Video("146", "Sound Of Music ", 1.00, 23);
videos[5]=new Video("147", "Planet Of The Apes", 5.00, 0);
videos[6]=new Video("148", "Mission Impossible", 1.00, 15);
videos[7]=new Video("150", "Bagdad by Night", 6.00, 5);
videos[8]=new Video("151", "Lord of the Rings 1", 5.00, 0);
customers [0]= new Customer("9902JI", "Innes ", 0,43484001);
customers [1]= new Customer("8906RH", "Herbert", 0,43484000);
customers [2]= new Customer("9012GT", "Turner ", 0,43480009);
customers [3]= new Customer("9012GS", "Sparke ", 0,43480007);
customers [4]= new Customer("9012MV", "Vallance", 0,43480008);
}
public static void ListCustomers(){
System.out.printf("%-6s %-5s %6s\n", "Customer ID", "Customer Name", " Customer Phone Number");
for (int i=0;i<customers.length;i++){
System.out.println(customers[i]);
}
}
public static void ListVideos(){
System.out.printf("%-8s %-17s %6s %6s\n", "Video ID", "VideoName", " Video Price Rate", " In Stock");
for (int i=0;i<videos.length;i++){
System.out.println(videos[i]);
}
}
public static void ListHires(){
System.out.printf("%s %s %s %s %s \n","HireID", "Cust Name", "Video Name", "Days Hired", "Hire Cost");
for (Hire hire: HireList){
String Customer = customers[hire.getID(hire.getVideoID())].getCustomerName();
String videoID = videos[hire.getID(hire.getVideoID())].getTitle();
double DailyRate = videos[hire.getID(hire.getVideoID())].getRate()*hire.getDaysHired();
System.out.printf("%d %s %s %d %1.2f \n",hire.getHireID(), Customer, videoID, hire.getDaysHired(), DailyRate);
}
}
public static void HireStatistics(){
System.out.printf("%s %s %s\n", "Video ID", "Video Name", "Days Hired");
for (Hire hire: HireList){
String videoID = videos[hire.getID(hire.getVideoID())].getTitle();
System.out.printf("%s %s %d \n",hire.getVideoID(), videoID, hire.getDaysHired());
}
}
public static void HireVideo(){
int count =0;
while (count == 0){
int hireID = 1000+ HireList.size()+1;
System.out.println("Enter Customer ID");
String customerID = "9902JI";
System.out.println("Enter Video ID");
String videoID = "140";
System.out.println("Enter Days Hired");
int daysHired = 4;
System.out.println("Enter Another Hire [Y/N]?");
String Yes = sc.next();
if(Yes.equals("y")){
count = 0;
}
else if (Yes.equals("n")){
count = 1;
}
HireList.add(new Hire(hireID,customerID, videoID, daysHired, 0));
}
}
public static void ReturnVideo(){
System.out.println("Enter Customer ID");
String customerID = "9902JI";
System.out.println("Enter Video ID");
String videoID = "140";
for (int i = 0; i < HireList.size();i++){
if (HireList.get(i).getCustomerID().equals(customerID)){
HireList.remove(i);
}
}
for (int ii = 0; ii < HireList.size();ii++){
if (HireList.get(ii).getVideoID().equals(videoID)){
HireList.remove(ii);
}
}
System.out.println("Removed " + customerID );
}
}
解决方案
The simplest approach, as mentioned before, would be simply to save each member in a text file and read them back in with a Scanner object (http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html).
If you are concerned with how to write to a text file, I would suggest reading this article: http://www.mkyong.com/java/how-to-write-to-file-in-java-bufferedwriter-example/ which explains how to use the FileWriter Object.
An alternative option would be to have Driver implement the serialisable interface which would allow you store the entire Driver object in a series of bytes, but this is slightly more complicated. A decent tutorial on serialisation can be found here: http://www.tutorialspoint.com/java/java_serialization.htm
这篇关于Java的如何一个ArrayList保存到一个文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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