Storing Record in Java Random Access File

This Java class, Record, defines a record for storing data in a random access file. It has two attributes: `name` (a string with a maximum length of 16 characters) and `id` (a string with exactly 4 digits). The class provides methods to read and write records to/from the file, as well as getter methods for retrieving the `id` and `name` values.

This class defines a record which is specifically for storing in
a Java random access file. See API of RandomAccessFile class in Java.
Attributes:
name - String, the max length is 16 chars
id - String, the number of digits in id is 4.
*
*/
import java.util.*;
import java.io.*;
public class Record
{
private String name;
private String id;
private int NAMELENGTH=16;
private int IDLENGTH=4;
public Record()
{
id = " ";
name = " ";
}
public Record(String newId, String newName)
{
id = newId;
name = newName;
}
//Read a 'name' and the related 'id' from the current position of
//the given file to the instance variables 'name' and 'id'
public void read(RandomAccessFile file) throws IOException
{
id = readString(file, IDLENGTH);
name = readString(file, NAMELENGTH);
}
//Write the value of 'this' object to the given file
public void write(RandomAccessFile file) throws IOException
{
writeStr(file, id, IDLENGTH);
writeStr(file, name, NAMELENGTH);
}
public String getId()
{
return id;
}

public String getName()
{
return name;
}
//Help method: read a string with length of strLength from the
file
// Return the string to the caller
private String readString (RandomAccessFile file, int strLength)
throws IOException
{
char[] chs = new char[strLength];
for (int i = 0; i < chs.length; i++)
{
chs[i] = file.readChar();
}
String theStr = new String(chs);
return theStr;
}
//Help method: write a string with length of strLength to the
file
private void writeStr( RandomAccessFile file, String str, int
strLength ) throws IOException
{
StringBuffer buffer = null;
if ( str != null )
buffer = new StringBuffer( str );
else
buffer = new StringBuffer( strLength );
buffer.setLength( strLength );
file.writeChars( buffer.toString() );
} // end method writeName
public String toString()
{
return "\nID: " + id + "\nName: " + name;
}
}