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我从学生数据库问题中读取二进制值时遇到了很多麻烦。经过一些修改后，我得到了输出正常工作，并在格式中，我想即（int id，字符串名称，int年龄），但是，我有很多麻烦从我的文件加载编码的二进制数据值。根据编译器，它一直读取直到UTF值，然后我收到一个EOFException。EOFException从二进制文件，学生数据库中读取UTF文件
这里是我试图完成的问题：
首先，启动程序后，用户选择的选项要么 1.学生添加到数据库 2.从学生数据库 3.在数据库中打印一个特定的学生 4.打印数据库中的所有学生
如果他们选择，用户将为学生添加一个Student obj。 学生obj包含一个ID（int），一个名称（字符串）和一个年龄（int）。
删除学生根据用户输入的ID号码将其从矢量中删除。
和选项3/4打印学生的obj（S）到屏幕本身（而不是二进制文件）
用户退出后，通过输入5的方案;向量中的学生obj被写入二进制文件。
当程序重新运行时，它会将学生obj加载回向量中。 （记住该文件被写入并从一个二进制文件加载）
我遇到的问题是当文件“Student.data”（我正在写入的文件）正在加载它不断扔我当我尝试读取学生姓名时，第198行处发生EOFException。
我相信问题可能出现在编写代码时，但我修改了我抓取名称值并多次写入的方式，但仍然无法正确加载它们。
有关如何解决此问题的任何建议？
代码：
//StudentDB.java
import java.util.Vector;
import java.io.*;
import java.util.Scanner;
class Student
{
private int id;
private String name;
private int age;
//Desc: Initializes the student to id=0, name="none", and age=0
public Student()
{
this.id=0;
this.name="none";
this.age=0;
}
//Desc: Initializes the student to id=i, name=n, age=a
public Student(int I, String n, int a)
{
this.id=I;
this.name=n;
this.age=a;
}
//Desc: Sets the current id to s
public void setID(int s)
{
this.id=s;
}
//Return: The current ID value
public int getID()
{
return this.id;
}
//Desc: sets the current name of the student to s
public void setName(String s)
{
this.name=s;
}
//Return: The current name of the student
public String getName()
{
return this.name;
}
//Desc: sets the current age of the obj to a
public void setAge(int a)
{
this.age=a;
}
//Return: The students current age
public int getAge()
{
return this.age;
}
//Return: True if id of this student equals id of obj, false otherwise
public boolean equals(Object obj)
{
Student stu= (Student)obj;
if(this.id==stu.id) return true;
else return false;
}
//Desc: Compares two students based on their ID to determine if they're
// the same
//Return: 1 if the current Student's ID is greater than stu
// 0 if the students ID's are the same
// -1 if Student stu's ID is larger
public int compareTo(Student stu)
{
if(this.id> stu.id) return 1;
else if(this.id==stu.id) return 0;
else return -1;
}
//Return: id+"Name"+age
public String toString()
{
return (this.getID()+ " "+this.getName()+" "+this.getAge());
}
}
public class StudentDB
{
private static Scanner keyboard=new Scanner(System.in);
//Desc: Maintains a database of Student Records. The database is stored in
// a binary file called "Student.data"
//Input: User enters commands from keyboard to manipulate database
//Output: Database updated as directed by user.
public static void main(String[]args) throws IOException
{
Vector<Student> v= new Vector<Student>();
File s= new File("Student.data");
if(s.exists()) loadStudent(v);
int choice=5;
do
{
System.out.println("\t1. Add a Student Record");
System.out.println("\t2. Remove a Student Record");
System.out.println("\t3. Print a Student Record");
System.out.println("\t4. Print all Student Records");
System.out.println("\t5. Quit");
choice= keyboard.nextInt();
keyboard.nextLine();
switch(choice)
{
case 1: addStudent(v); break;
case 2: removeStudent(v); break;
case 3: printStudent(v); break;
case 4: printAllStudent(v); break;
default: break;
}
} while(choice!=5);
storeStudent(v);
}
//Input: user enters an integer(id), a string(name), an integer(age) from
//the keyboard all on seperate lines
//Post: The input record added to v if id does not exist
//Output: various prompts as well as "Student Added" or "Add failed:
// Student already exists" printed on the screen accordingly
public static void addStudent(Vector<Student> v)
{
Student stu= new Student();
System.out.print("Please enter a Student ID:");
stu.setID(keyboard.nextInt());
keyboard.nextLine();
System.out.print("Please enter a Student Name:");
stu.setName(keyboard.nextLine());
System.out.print("Please enter a Student Age:");
stu.setAge(keyboard.nextInt());
keyboard.nextLine();
int index= v.indexOf(stu);
if(index==-1)
{
v.add(stu);
System.out.println("Student Added");
}
else System.out.println("Add failed: Student already exists");
}
//Input: user enters an integer(id) from the Keyboard
//Post: The records in v whose id field matches the input removed from v
//Output: various prompts as well as "Student removed" or "Remove failed:
// Student does not exsist" printed on the screen accordingly
public static void removeStudent(Vector<Student>v)
{
System.out.print("Student ID:");
int id= keyboard.nextInt();
Student stu= new Student(id,"",99);
if(v.remove(stu)) System.out.println("Student Removed");
else System.out.println("Remove Failed");
}
//Input: user enters an integer(id) from the Keyboard
//Output: various prompts as well as the record in v whose id field
// matches the input printed on the screen or "Print failed: Student
// does not exsist" printed on the screen accordingly
public static void printStudent(Vector<Student>v)
{
System.out.print("Student ID:");
int id= keyboard.nextInt();
Student stu= new Student(id,"",99);
int index=v.indexOf(stu);
if(index!=-1)
{
System.out.println(v.get(index).toString());
}
else System.out.println("Print failed: Student does not exsist!");
}
//Output: All records in v printed on the screen
public static void printAllStudent(Vector<Student>v)
{
Student stu=new Student();
for(int i=0; i<v.size();++i)
{
stu=v.get(i);
System.out.println(stu);
}
}
//Input: Binary file Student.data must exist and contains student records
//Post: All records in Student.data loaded into vector v.
public static void loadStudent(Vector<Student>v)throws IOException
{
Student stu;
int c;
DataInputStream f= new DataInputStream(
new FileInputStream("Student.data"));
try {
while(true)
{
stu=new Student();
int id=f.readInt();
stu.setID(id);
String name= f.readUTF();
stu.setName(name);
int age= f.readInt();
stu.setAge(age);
v.add(stu);
}
}
catch(EOFException e)
{
System.out.println("Error!: End of File Exception");
f.close();
}
catch(IOException e)
{
System.out.println("Error Reading File");
f.close();
System.exit(1);
}
f.close();
}
//Output: All records in v written to binary file Student.data
public static void storeStudent(Vector<Student>v) throws IOException
{
Student stu= new Student();
DataOutputStream s= new DataOutputStream(
new FileOutputStream("Student.data"));
for(int i=0; i<v.size(); ++i)
{
stu=v.get(i);
s.writeInt(stu.getID());
s.writeUTF(stu.getName());
s.writeInt(stu.getAge());
}
s.close();
}
}
编辑出你的名字和电子邮件大声笑。还提供样本用法。遇到错误的'main'方法。 – JordanGS
由于文件中存在随机垃圾字符，请查看十六进制编辑器并亲自查看。您不必删除学生导致错误。你所要做的就是添加一个学生。这意味着您的写入操作很糟糕。 – JordanGS