当我从文件反序列化我的对象时，我得到一个ClassCastException。当我检查文件时，对象就在那里，所以我知道它正在被正确序列化。由于某种原因，代码在尝试检索对象时中断。这个想法是允许用户按日期检查他们在日志中记录的所有锻炼。此外，我已经尝试实现比较器，但我一直得到同样的错误，我完全没有想法。任何帮助将不胜感激。
以下是造成问题的代码：
case Logger.CHECK_KEY:
//TODO
try {
workoutLog = (WorkoutLog) SerializationUtil.deserialize(file);
System.out.println("Deserializing from:..." + file.getName());
}
这是workoutLog类：
public class WorkoutLog implements Serializable{
public TreeMap < String , Workout > mWorkoutLog;
// thia is the actual Workoutlog
public WorkoutLog(){
mWorkoutLog = new TreeMap<>();
}
//the string key will be the workouts formatted date
public TreeMap < String, Workout> getWorkoutLog(){
return mWorkoutLog;
}
我包含了上下文代码的主体
package com.alejandro;
import com.alejandro.Utilities.SerializationUtil;
import com.alejandro.model.Exercise;
import com.alejandro.model.Workout;
import com.alejandro.model.WorkoutLog;
import com.sun.istack.internal.NotNull;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.util.Scanner;
import java.util.TreeMap;
public class Logger {
public static final String COMPLETE_KEY = "COMPLETE";
public static final String INCOMPLETE_KEY = "INCOMPLETE";
public static final String ADD_KEY = "ADD";
public static final String CHECK_KEY = "CHECK";
public static final String EXIT_KEY = "EXIT";
public static void main(String[] args) throws IOException, ClassNotFoundException {
Logger logger = new Logger();
WorkoutLog workoutLog = new WorkoutLog();
Workout workout = new Workout();
File file = new File("workout.txt");
//im going to need to ask if the user wants to add a workout, close the program, or select a workout
String userInput = checkUserIntention();
//the switch statement goes through all the possible user inputs
switch(userInput){
case Logger.ADD_KEY:
printInstructions();
do{
logger.promptForExerciseData(workout);
}while(!checkIfUserIsDone());
workoutLog.getWorkoutLog().put(workout.getDate(),workout);
SerializationUtil.serialize(workoutLog,file);
System.out.println("Workout saved in..." +file.getName());
break;
case Logger.CHECK_KEY:
//TODO
try {
workoutLog = (WorkoutLog) SerializationUtil.deserialize(file);
System.out.println("Deserializing from:..." + file.getName());
System.out.println(workoutLog.getWorkoutLog().keySet()+"");
} catch(EOFException e){
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}catch(ClassCastException E){
E.printStackTrace();
}
break;
case Logger.EXIT_KEY:
System.out.println("\nExiting program...");
break;
}
}
//I'm using this method to explain to the user how to use the program
protected static void printInstructions(){
System.out.println("\nWelcome to Mr.Strong!\n");
System.out.println("This program was developed to help powerlifters keep a log of their lifts.\n");
System.out.println("Because of this, the program will only recognize the following lifts:\n");
System.out.println("Squat, Bench, Deadlift, Press.\n");
System.out.println("The program is case-sensitive, make sure the information is entered as stated above.\n");
}
//this method asks the user for information about the lifts stores them in a workout object
//the methods used here are all organized throught the page, its just to keep things cleaner and separate
protected void promptForExerciseData(Workout workout){
Exercise exercise = new Exercise();
askForExerciseIdentity(exercise);
askForNumsRelLifts(exercise);
workout.getExerciseList().add(exercise);
}
//this will check to see if the user is done inputting the exercises he did, if he finished the program ends.
protected static boolean checkIfUserIsDone(){
Scanner scanner = new Scanner(System.in);
boolean isUserDone = false;
System.out.println("\nEnter: 'complete'" + ", if you are done. " +
"If not, enter:'incomplete " + ".\n");
String answer = scanner.nextLine();
if(answer.trim().toUpperCase().equals(Logger.COMPLETE_KEY)){
isUserDone = true;
} else if(answer.trim().toUpperCase().equals(Logger.INCOMPLETE_KEY)){
isUserDone = false;
} else{
checkIfUserIsDone();
}
return isUserDone;
}
//check if user wants to add, review, or close
protected static String checkUserIntention(){
String answer = "a";
Scanner scanner = new Scanner(System.in);
System.out.println("\nPlease choose an option:\n" +
"1-) Add a workout. Enter 'Add'.\n" +
"2-) Check a workout Enter 'Check'.\n" +
"3-) Exit the program. Enter 'Exit'\n");
answer = scanner.nextLine();
if(answer.trim().toUpperCase().equals(Logger.ADD_KEY) ||
answer.trim().toUpperCase().equals(Logger.CHECK_KEY)||
answer.trim().toUpperCase().equals(Logger.EXIT_KEY)){
return answer.toUpperCase();
}else{
System.out.println("Incorrect input.");
checkUserIntention();
}
return answer;
}
//all of this part is asking for the exercise data
//this is the part that asks for exercise id
protected void askForExerciseIdentity(Exercise exercise){
Scanner scanner = new Scanner(System.in);
do{
System.out.println("\nEnter a lift:\n");
String exerciseIdentity = scanner.nextLine();
if(exerciseIdentity.equals(exercise.SQUAT_KEY)){
exercise.setExerciseIdentity(exercise.SQUAT_KEY);
}else if(exerciseIdentity.equals(exercise.PRESS_KEY)){
exercise.setExerciseIdentity(exercise.PRESS_KEY);
}else if(exerciseIdentity.equals(exercise.BENCH_KEY)){
exercise.setExerciseIdentity(exercise.BENCH_KEY);
}else if(exerciseIdentity.equals(exercise.DEADLIFT_KEY)){
exercise.setExerciseIdentity(exercise.DEADLIFT_KEY);
}else {
exercise.setExerciseIdentity(null);
System.out.println("Please enter a valid exercise.");
}}while(exercise.getExerciseIdentity() == null);
}
//this is the part that aks for numbers
protected void askForNumsRelLifts(Exercise exercise){
exercise.setWeightUsed(askForWeightUsed());
exercise.setNumOfReps(askForNumOfReps());
exercise.setNumOfSets(askForNumOfSets());
}
protected double askForWeightUsed(){
Scanner scanner = new Scanner(System.in);
double weightUsed;
do{
try{
System.out.println("\nEnter weight used:\n");
weightUsed = Double.parseDouble(scanner.nextLine());
}catch(NumberFormatException e){
System.out.println("\nPlease enter a valid number\n");
weightUsed = 0;
}
} while(weightUsed == 0);
return weightUsed;
}
protected double askForNumOfSets(){
Scanner scanner = new Scanner(System.in);
double numOfSets;
do{
try{
System.out.println("\nEnter sets done:\n");
numOfSets = Double.parseDouble(scanner.nextLine());
}catch(NumberFormatException e){
System.out.println("\nPlease enter a valid number\n");
numOfSets = 0;
}
}while(numOfSets == 0);
return numOfSets;
}
protected double askForNumOfReps(){
Scanner scanner = new Scanner(System.in);
double reps;
do{
try{
System.out.println("\nEnter reps done:\n");
reps = Double.parseDouble(scanner.nextLine());
} catch(NumberFormatException e){
System.out.println("\nPlease enter a valid number\n");
reps = 0;
}
}while(reps == 0);
return reps;
}
}
这是锻炼包括：
public class Workout implements Serializable{
protected ArrayList<Exercise> mExerciseList;
protected Date mDateCreated;
public Workout(){
mExerciseList = new ArrayList<>();
mDateCreated = new Date();
}
public ArrayList<Exercise> getExerciseList(){
return mExerciseList;
}
public String getDate(){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
return sdf.format(mDateCreated);
}}
这是seralizationutil：
import com.alejandro.model.WorkoutLog;
import java.io.*;
public class SerializationUtil{
public static Object deserialize(File filename) throws IOException, ClassNotFoundException{
FileInputStream fis = new FileInputStream(filename);
Object obj = new Object();
BufferedInputStream bis = new BufferedInputStream(fis);
ObjectInputStream ois = new ObjectInputStream(bis);
while(fis.available()>0){
obj = ois.readObject();
}
ois.close();
return obj;
}
public static void serialize(Object object, File filename) throws IOException{
FileOutputStream fos = new FileOutputStream(filename);
BufferedOutputStream bos = new BufferedOutputStream(fos);
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos.writeObject(object);
oos.close();
}}
这是编译器给我的：
java.lang.ClassCastException: java.lang.Object cannot be cast to com.alejandro.model.WorkoutLog
at com.alejandro.Logger.main(Logger.java:56)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
答案 0 :(得分：0)
试试这个简单的例子，我已经广泛修改了你的代码
还有一件事，我不知道你在SerializationUtil下有什么实现，所以我创建了自己的实现
我的示例没有任何问题
package week4;
import java.io.Serializable; import java.util.TreeMap;
public class WorkoutLog实现Serializable { 公共TreeMap＆lt;字符串，锻炼＆gt; mWorkoutLog;
// thia is the actual Workoutlog
public WorkoutLog(){
mWorkoutLog = new TreeMap<>();
}
//the string key will be the workouts formatted date
public TreeMap < String, Workout> getWorkoutLog(){
return mWorkoutLog;
}
}
package week4;
import java.io.Serializable;
public class Workout实现Serializable {
String date = "2016-01-13";
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
}
package week4;
import java.io.File; import java.io.IOException;
公共类TestWorkOut {
public static void main(String[] args) throws IOException, ClassNotFoundException {
WorkoutLog workoutLog = new WorkoutLog();
Workout workout = new Workout();
/* I had path to workout.txt as D:\\workout.txt*/
File file = new File("D:\\workout.txt");
workoutLog.getWorkoutLog().put(workout.getDate(),workout);
SerializationUtil.serialize(workoutLog,file);
System.out.println("Workout saved in..." +file.getName());
workoutLog = (WorkoutLog) SerializationUtil.deserialize(file);
System.out.println("Deserializing from:..." + file.getName());
System.out.println(workoutLog.getWorkoutLog().keySet()+"");
}
}
package week4;
import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream;
public class SerializationUtil {
public static void serialize(WorkoutLog workoutLog, File filename) {
FileOutputStream fos = null;
ObjectOutputStream out = null;
try {
fos = new FileOutputStream(filename);
out = new ObjectOutputStream(fos);
out.writeObject(workoutLog);
out.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
public static WorkoutLog deserialize(File filename) {
FileInputStream fis = null;
ObjectInputStream in = null;
WorkoutLog workout = null;
try {
fis = new FileInputStream(filename);
in = new ObjectInputStream(fis);
workout = (WorkoutLog) in.readObject();
in.close();
} catch (Exception ex) {
ex.printStackTrace();
}
return workout;
}
}
输出
锻炼保存在... workout.txt
反序列化：... workout.txt
[2016年1月13日]