1: ……
2: public void f() {
3: Properties props = new Properties();
4: ....
5: if ( in !=null && in.available() > 0 ) {
6: props.load(in);
7: if ( props == null || props.isEmpty() )
8: return ;
9: }
10: String type = props.getProperty("type");
11: Worker w;
12:
13: // 외부 입력되는 값에 대해 유효성을 검증하여야한다.
14: if (type == null || "".equals(type)) return;
15: if (type.equals("Slow" )) {
16: w = new SlowWorker();
17: w.doAction();
18: } else if (type.equals("Hard" )) {
19: w = new HardWorker();
20: w.doAction();
21: } else {
22: System.err.printf("No propper class name!");
23: }
24: ……
25: }
26:
27: abstract class Worker {
28: String work = "";
29: public abstract void doAction();
30: }