Java源码——读取顺序存取文件中的数据（read text file and display each record）

代码如下：

// Fig. 15.6: ReadTextFile.java
// This program reads a text file and displays each record.
package ch15;
import java.io.IOException;
import java.lang.IllegalStateException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.NoSuchElementException;
import java.util.Scanner;

public class ReadTextFile
{
private static Scanner input;

public static void main(String[] args)
{
openFile();
readRecords();
closeFile();
}

// open file clients.txt
public static void openFile()
{
try
{
input = new Scanner(Paths.get("clients.txt"));
}
catch (IOException ioException)
{
System.err.println("Error opening file. Terminating.");
System.exit(1);
}
}

// read record from file
public static void readRecords()
{
System.out.printf("%-10s%-12s%-12s%10s%n", "Account",
"First Name", "Last Name", "Balance");

try
{
while (input.hasNext()) // while there is more to read
{
// display record contents
System.out.printf("%-10d%-12s%-12s%10.2f%n", input.nextInt(),
input.next(), input.next(), input.nextDouble());
}
}
catch (NoSuchElementException elementException)
{
System.err.println("File improperly formed. Terminating.");
}
catch (IllegalStateException stateException)
{
System.err.println("Error reading from file. Terminating.");
}
} // end method readRecords

// close file and terminate application
public static void closeFile()
{
if (input != null)
input.close();
}
} // end class ReadTextFile

调试结果：
Account   First Name  Last Name      Balance

1         a           b                 1.00

2         c           d                 3.00

3         e           f                 8.00