我正在使用随机访问文件来编写使用 arrayList 存储的 raf。我不知道它是否可以完成，但我正在尝试，因为它是我创建此应用程序的最佳解决方案。
这是我得到的运行时错误：
Exception in thread "main" java.io.EOFException
at java.io.RandomAccessFile.readChar(Unknown Source)
at Student.read(Student.java:93)
at MainApp.start(MainApp.java:60)
at MainApp.main(MainApp.java:17)
这是我的代码：
MainApp
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.RandomAccessFile;
public class MainApp
{
public static void main(String[] args) throws Exception
{
new MainApp().start();
}
public void start()throws Exception
{
StudentStore details = new StudentStore();
//Student a = new Student("Becky O'Brien", "DKIT26", "0876126944", "bexo@hotmail.com");
//details.print();
RandomAccessFile raf = new RandomAccessFile("ContactDetails.txt", "rw");
Student a = new Student("Becky O'Brien", "DKIT26", "0876126944", "bexo@hotmail.com");
Student b = new Student("Fabio Borini", "DKIT28", "0876136944", "fabioborini@gmail.com");
Student c = new Student("Gaston Ramirez", "DKIT29", "0419834501", "gramirez@webmail.com");
Student d = new Student("Luis Suarez", "DKIT7", "0868989878", "luissuarez@yahoo.com");
Student e = new Student("Andy Carroll", "DKIT9", "0853456788", "carroll123@hotmail.com");
details.add(a);
details.add(b);
details.add(c);
details.add(d);
details.add(e);
for (int i = 0; i < details.size(); i++)
{
//a.setStudentName(a[i]);
//a.setLastName(lnames[i]);
// a.setAddress(addresses[i]);
// a.setAge(ages[i]);
// a.setSalary(salaries[i]);
a.write(raf);
}
raf = new RandomAccessFile("employee.dat", "rw");
// er = new Student();
int numRecords = (int) raf.length() / details.size();
for (int i = 0; i < numRecords; i++) {
a.read(raf);
System.out.print(a.getStudentName() + " ");
System.out.print(a.getStudentId() + " ");
System.out.print(a.getStudentEmail() + " ");
System.out.print(a.getStudentTelephoneNumber() + " ");
}
raf.seek(0);
for (int i = 0; i < numRecords; i++)
{
a.read(raf);
raf.seek(raf.getFilePointer() - details.size());
a.write(raf);
raf.seek(raf.getFilePointer() - details.size());
a.read(raf);
}
System.out.print(a.getStudentName() + " ");
System.out.print(a.getStudentId() + " ");
System.out.print(a.getStudentEmail() + " ");
System.out.print(a.getStudentTelephoneNumber() + " ");
}
}
学生
import java.io.IOException;
import java.io.RandomAccessFile;
public class Student
{
//---------------------------------------------------------------------------
// Class Variables.
//---------------------------------------------------------------------------
private String studentName;
private String studentId;
private String studentTelephoneNumber;
private String studentEmail;
//---------------------------------------------------------------------------
// Constructor.
//---------------------------------------------------------------------------
public Student(String studentName, String studentId,String studentTelephoneNumber, String studentEmail)
{
this.studentName = studentName;
this.studentId = studentId;
this.studentTelephoneNumber = studentTelephoneNumber;
this.studentEmail = studentEmail;
}
//---------------------------------------------------------------------------
// Getters.
//---------------------------------------------------------------------------
public String getStudentName()
{
return studentName;
}
public String getStudentId()
{
return studentId;
}
public String getStudentTelephoneNumber()
{
return studentTelephoneNumber;
}
public String getStudentEmail()
{
return studentEmail;
}
//---------------------------------------------------------------------------
// Setters.
//---------------------------------------------------------------------------
public void setStudentName(String studentName)
{
this.studentName = studentName;
}
public void setStudentId(String studentId)
{
this.studentId = studentId;
}
public void setStudentTelephoneNumber(String studentTelephoneNumber)
{
this.studentTelephoneNumber = studentTelephoneNumber;
}
public void setStudentEmail(String studentEmail)
{
this.studentEmail = studentEmail;
}
//---------------------------------------------------------------------------
// toString.
//---------------------------------------------------------------------------
public String toString()
{
return "---------------------------Student--------------------------- " +
"\nStudent Name:" + studentName +
"\nStudent Id:"+ studentId +
"\nStudent Telephone Number:"+ studentTelephoneNumber +
"\nStudent Email:" + studentEmail;
}
void read(RandomAccessFile raf) throws IOException
{
char[] temp = new char[15];
for (int i = 0; i < temp.length; i++)
temp[i] = raf.readChar();
studentName = new String(temp);
temp = new char[15];
for (int i = 0; i < temp.length; i++)
temp[i] = raf.readChar();
studentId = new String(temp);
temp = new char[30];
for (int i = 0; i < temp.length; i++)
temp[i] = raf.readChar();
studentEmail = new String(temp);
temp = new char[30];
for (int i = 0; i < temp.length; i++)
temp[i] = raf.readChar();
studentTelephoneNumber = new String(temp);
temp = new char[30];
for (int i = 0; i < temp.length; i++)
temp[i] = raf.readChar();
}
void write(RandomAccessFile raf) throws IOException
{
StringBuffer sb;
if (studentName != null)
sb = new StringBuffer(studentName);
else
sb = new StringBuffer();
sb.setLength(15);
raf.writeChars(sb.toString());
if (studentId != null)
sb = new StringBuffer(studentId);
else
sb = new StringBuffer();
sb.setLength(15);
raf.writeChars(sb.toString());
if (studentEmail != null)
sb = new StringBuffer(studentEmail);
else
sb = new StringBuffer();
sb.setLength(30);
raf.writeChars(sb.toString());
if (studentTelephoneNumber != null)
sb = new StringBuffer(studentTelephoneNumber);
else
sb = new StringBuffer();
sb.setLength(30);
raf.writeChars(sb.toString());
}
}