将值与文本文件[Java]中的HashMap中的键相关联

我有一个文本文件，该文件具有打印机，然后是与该打印机关联的打印作业：

LaserJet This assignment involves . . .
LaserJet Budget for November . . .
Lexmark Invoice Number 334222: . . .
Samsung Class schedule for 2013/01/06 . . .
Lexmark Production schedule . . .
Samsung Class schedule for 2013/02/06 . . .
LaserJet Memo to Bobby Hill . . .
Lexmark Meeting in 20 minutes . . .
Lexmark Conference call transcript . . .
Lexmark Production schedule is off time . . .
Lexmark Last Production schedule . . .
LaserJet Print a crapload of pages . . .

我想将文本文件读入程序，并创建一个以打印机名称为键的HashMap，并将printjob与相应的打印机关联。所以我最终会得到类似：

LaserJet
This assignment involves . . .
udget for November . . .
Memo to Bobby Hill . . .
Print a crapload of pages . . .

Samsung
Class schedule for 2013/01/06 . . .
Class schedule for 2013/02/06 . . .

Lexmark
Invoice Number 334222: . . .

等等（该文件可能包含1000份使用许多不同打印机的作业）。我正在努力将printjob与它的打印机相关联。到目前为止，这是我的代码：

import java.util.*;
public class Printers {

private String sPrinterName;
private String sContent;
private Map<String, ArrayList<String>> mapOfJobs = new HashMap<String, ArrayList<String>>();
private ArrayList<String> collectionContent = new ArrayList<String>();
private ArrayList<String> collectionPrinters = new ArrayList<String>();

public Printers() { }

public void loadCollections( Scanner input ) {
    while ( input.hasNext() ) {
        sPrinterName = input.next(); // get printer name
        sContent = input.nextLine(); // get string ( print job )
        if ( !collectionPrinters.contains(sPrinterName))
            collectionPrinters.add(sPrinterName);
        collectionContent.add(this.sContent);
    }
}

public void buildMap() { // the process of creating the HashMap
    for ( int i = 0; i < collectionPrinters.size(); i++ ) {
        String refToPrinter = collectionPrinters.get(i);
        String refToContent = collectionContent.get(i);
        if ( !mapOfJobs.containsKey( refToPrinter ) ) {
                ArrayList<String> tmp = new ArrayList<String>();
                tmp.add( refToContent );
                mapOfJobs.put( refToPrinter, tmp );
        }
        else if ( !mapOfJobs.get( refToPrinter ).contains( refToContent ) )
            mapOfJobs.get( refToPrinter ).add( refToContent );
    }
} 

public void displayAll() { // print everything
    Iterator iterator = mapOfJobs.keySet().iterator();

    while (iterator.hasNext()) {
       String key = iterator.next().toString();
       String value = mapOfJobs.get(key).toString();

       System.out.println(key + " " + value);
    }

}

public String toString() {
    return String.format("Printer: %s     Job: %s", sPrinterName, sContent );
}
}

我有一个主要的类，它创建一个Printers对象来调用方法。无论如何，代码仅输出：

LaserJet [ This assignment involves . . .]
Lexmark [ Budget for November . . .]
Samsung [ Invoice Number 334222: . . .]

帮助表示赞赏。