Java Can';似乎无法让它先写入arrayList,然后再写入文件
我一直在做这个,似乎无法让它正常运行。它应该创建一个arraylist,然后添加、删除、标记为借出、标记为返回,并在退出时写入文件。我找不到我搞砸的东西Java Can';似乎无法让它先写入arrayList,然后再写入文件,java,Java,我一直在做这个,似乎无法让它正常运行。它应该创建一个arraylist,然后添加、删除、标记为借出、标记为返回,并在退出时写入文件。我找不到我搞砸的东西 package cs1181proj1; import static cs1181proj1.Media.media; import java.io.DataOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoun
package cs1181proj1;
import static cs1181proj1.Media.media;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.InputMismatchException;
import java.util.Scanner;
/**
*
* @author Veteran
*/
public class CS1181Proj1 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// Create ArrayList and mediaFile.
ArrayList<Media> Item = new ArrayList<>();
Scanner keyboard = new Scanner(System.in);
File mediaFile = new File("mediaFile.dat");
String Title;
String Format;
String loanedTo = null;
String dateLoaned = null;
int number = 0;
if (mediaFile.exists()) {
try {
try (ObjectInputStream dos = new ObjectInputStream(
new FileInputStream(mediaFile))) {
Item = (ArrayList<Media>) dos.readObject();
}
} catch (FileNotFoundException a) {
System.out.println("Thou hast erred! The file doth not exist!");
} catch (IOException b) {
System.out.println("GIGO My Lord or Lady!");
} catch (ClassNotFoundException c) {
System.out.println("Avast! I am in a quandry");
}
}
//Print out menu of choices
while (number != 6) {
System.out.println("");
System.out.println("1. Add new media item");
System.out.println("2. Mark an item out on loan");
System.out.println("3. Mark an item as Returned");
System.out.println("4. List items in collection");
System.out.println("5. Remove a media item");
System.out.println("6. Quit");
System.out.println("");
//accept users menu choice
try {
number = keyboard.nextInt();
} catch (InputMismatchException e) {
System.out.println("That's not a number between 1 and ` `6. IS IT!");
}
//Switch to tell program what method to use depending on user ` `//option
switch (number) {
case 1:
insert();
break;
case 2:
onLoan();
break;
case 3:
returned();
break;
case 4:
list();
break;
case 5:
removeItem();
break;
case 6:
System.out.println("Goodbye");
Quit(mediaFile);
break;
}
}
}
//Method for inserting items in arraylist
public static void insert() {
ArrayList<Media> media = new ArrayList<>();
System.out.println("New titles name");
Scanner newEntry = new Scanner(System.in);
String title = newEntry.nextLine();
System.out.println("");
//title of media
while (titleAlreadyExists(title, media)) {
System.out.println("Title already exists");
title = newEntry.nextLine();
System.out.println("");
}
//format of media
System.out.println("What format");
String format = newEntry.nextLine();
media.add(new Media(title, format));
System.out.println("Your entry has been created.");
}
//In case entry already exists
public static boolean titleAlreadyExists(
String title, ArrayList<Media> media) {
for (Media entry : media) {
if (entry.getTitle().equals(title)) {
return true;
}
}
return false;
}
//Method for putting item on loan
public static void onLoan() {
System.out.println("Enter name of Title on loan");
Scanner newLoan = new Scanner(System.in);
ArrayList<Media> media = new ArrayList<>();
String loanTitle = newLoan.nextLine();
System.out.println("Who did you loan this to");
Scanner To = new Scanner(System.in);
String loanedTo = To.nextLine();
System.out.println("");
System.out.println("When was it lent out?");
Scanner date = new Scanner(System.in);
String dateLoaned = date.nextLine();
System.out.println("");
for (Media title : media) {
if (title.getTitle().equals(loanTitle)) {
title.setDateLoaned(dateLoaned);
title.setloanedTo(loanedTo);
System.out.println(title + " loaned to " + loanedTo + ` `"on date" + dateLoaned + "is listed as loaned");
}
}
}
//Method for returning item in collection
public static void returned() {
System.out.println("Enter name of Title returned");
Scanner returned = new Scanner(System.in);
ArrayList<Media> media = new ArrayList<>();
String returnedTitle = returned.nextLine();
String loanedTo = null;
String dateLoaned = null;
System.out.println("");
for (Media title : media) {
if (title.getTitle().equals(returnedTitle)) {
title.setDateLoaned(dateLoaned);
title.setloanedTo(loanedTo);
System.out.println(title + "is listed as returned");
}
}
}
//Method for listing items in collection
public static void list() {
System.out.println("Your collection contains:");
for (int i = 0; i < media.size(); i++) {
System.out.print((media.get(i)).toString());
System.out.println("");
}
}
//method for removing an item from the collection
private static void removeItem() {
System.out.println("What item do you want to remove?");
Scanner remover = new Scanner(System.in);
ArrayList<Media> media = new ArrayList<>();
String removeTitle = remover.nextLine();
System.out.println("");
media.stream().filter((title) -> ` ` (title.getTitle().equals(removeTitle))).forEach((title) -> {
media.remove(removeTitle);
System.out.println(title + "has been removed");
});
}
//method for saving to file when the user quits the program.
//To ensure there is no data loss.
public static void Quit(File mediaFile) {
try {
ArrayList<Media> media = new ArrayList<>();
try (ObjectOutputStream oos = new ObjectOutputStream(new ` ` FileOutputStream(mediaFile))) {
oos.writeObject(media);
System.out.println("Your file has been saved.");
}
} catch (IOException e) {
System.out.println("Unable to write to file. Data not ` `saved");
}
}
}
包cs1181proj1;
导入静态cs1181proj1.Media.Media;
导入java.io.DataOutputStream;
导入java.io.File;
导入java.io.FileInputStream;
导入java.io.FileNotFoundException;
导入java.io.FileOutputStream;
导入java.io.IOException;
导入java.io.ObjectInputStream;
导入java.io.ObjectOutputStream;
导入java.io.PrintWriter;
导入java.util.ArrayList;
导入java.util.InputMismatchException;
导入java.util.Scanner;
/**
*
*@作家老兵
*/
公共类CS1181Proj1{
/**
*@param指定命令行参数
*/
公共静态void main(字符串[]args){
//创建ArrayList和mediaFile。
ArrayList项=新建ArrayList();
扫描仪键盘=新扫描仪(System.in);
文件mediaFile=新文件(“mediaFile.dat”);
字符串标题;
字符串格式;
字符串loanedTo=null;
字符串dateLoaned=null;
整数=0;
if(mediaFile.exists()){
试一试{
try(ObjectInputStream dos=newobjectinputstream(
新文件输入流(mediaFile))){
Item=(ArrayList)dos.readObject();
}
}捕获(FileNotFoundException a){
System.out.println(“你犯了错误!文件不存在!”);
}捕获(IOB异常){
System.out.println(“吉戈,我的主人或夫人!”);
}捕获(ClassNotFoundException c){
System.out.println(“Avast!我在quandry中”);
}
}
//打印出选项菜单
while(数字!=6){
System.out.println(“”);
System.out.println(“1.添加新媒体项”);
System.out.println(“2.标记借出的项目”);
System.out.println(“3.将项目标记为已退回”);
System.out.println(“4.列出集合中的项目”);
System.out.println(“5.删除媒体项”);
System.out.println(“6.Quit”);
System.out.println(“”);
//接受用户的菜单选择
试一试{
number=键盘.nextInt();
}捕获(输入不匹配异常e){
System.out.println(“这不是一个介于1和``6.IS`之间的数字!”);
}
//根据用户``//选项,切换以告知程序要使用的方法
开关(编号){
案例1:
插入();
打破
案例2:
onLoan();
打破
案例3:
返回();
打破
案例4:
list();
打破
案例5:
removeItem();
打破
案例6:
System.out.println(“再见”);
退出(媒体文件);
打破
}
}
}
//在arraylist中插入项的方法
公共静态void insert(){
ArrayList媒体=新的ArrayList();
System.out.println(“新标题名称”);
Scanner newEntry=新扫描仪(System.in);
字符串title=newEntry.nextLine();
System.out.println(“”);
//媒体名称
while(标题已存在(标题、媒体)){
System.out.println(“标题已存在”);
title=newEntry.nextLine();
System.out.println(“”);
}
//媒体格式
System.out.println(“什么格式”);
字符串格式=newEntry.nextLine();
添加(新媒体(标题、格式));
System.out.println(“您的条目已创建”);
}
//以防条目已存在
公共静态布尔标题ReadyExists(
字符串标题,ArrayList媒体){
用于(媒体条目:媒体){
if(entry.getTitle().equals(title)){
返回true;
}
}
返回false;
}
//借出物品的方法
公共静态void onLoan(){
System.out.println(“输入贷款所有权名称”);
扫描仪newLoan=新扫描仪(System.in);
ArrayList媒体=新的ArrayList();
String loanTitle=newLoan.nextLine();
System.out.println(“你把这个借给谁了”);
扫描器到=新扫描器(System.in);
字符串loanedTo=To.nextLine();
System.out.println(“”);
System.out.println(“它是什么时候借出的?”);
扫描仪日期=新扫描仪(System.in);
字符串dateLoaned=date.nextLine();
System.out.println(“”);
用于(媒体标题:媒体){
if(title.getTitle().equals(loanTitle)){
标题:setDateLoaned(dateLoaned);
标题:setloanedTo(loanedTo);
System.out.println(title+“借出给”+借出给”+“`”于日期“+借出日期+”列为借出”);
}
}
}
//返回集合中的项的方法
返回的公共静态void(){
System.out.println(“输入返回的标题名称”);
返回的扫描仪=新扫描仪(System.in);
ArrayList媒体=新的ArrayList();
字符串returnedTitle=returned.nextLine();
字符串loanedTo=null;
字符串dateLoaned=null;
System.out.println(“”);
用于(媒体标题:媒体){
if(title.getTitle().equals(returnedTitle)){
标题:setDateLoaned(dateLoaned);
标题:setloanedTo(loanedTo);
System.out.println(title+“列为已返回”);
}
}
}
//方法列出collectio中的项
package cs1181proj1;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Comparator;
/**
*
* @author Veteran
*/
public class Media implements Serializable {
static ArrayList<String> media = new ArrayList<>();
private String Title;
private String Format;
private String loanedTo = null;
private String dateLoaned = null;
Media() {
this.Title = ("Incorrect");
this.Format = ("Incorrect");
this.loanedTo = ("Available");
this.dateLoaned = ("Available");
}
Media(String Title, String Format) {
this.Title = Title;
this.Format = Format;
this.loanedTo = ("Available");
this.dateLoaned = ("Available");
}
//Get and Set Title
public String getTitle() {
return this.Title;
}
public void setTitle(String Title) {
this.Title = Title;
}
//Get and Set Format
public String getFormat() {
return this.Format;
}
public void setFormat(String Format) {
this.Format = Format;
}
//Get and Set loanedTo
public String getLoanedTo() {
return this.loanedTo;
}
public void setloanedTo (String loanedTo){
this.loanedTo = loanedTo;
}
//Get and set dateLoaned
public String getDateLoaned() {
return this.dateLoaned;
}
public void setDateLoaned(String dateLoaned){
this.dateLoaned = dateLoaned;
}
@Override
public String toString(){
return this.Title + ", " + this.Format +", " + this.loanedTo + ", "
+ this.dateLoaned;
}
public static Comparator <Media> TitleComparator = new Comparator <Media>(){
@Override
public int compare(Media t, Media t1) {
String title = t.getTitle().toUpperCase();
String title1 = t1.getTitle().toUpperCase();
return title.compareTo(title1);
}
};
}