holder2.java

来自「Thinking in JAVA第四版源代码」· Java 代码 · 共 17 行

//: generics/Holder2.java

public class Holder2 {
  private Object a;
  public Holder2(Object a) { this.a = a; }
  public void set(Object a) { this.a = a; }
  public Object get() { return a; }
  public static void main(String[] args) {
    Holder2 h2 = new Holder2(new Automobile());
    Automobile a = (Automobile)h2.get();
    h2.set("Not an Automobile");
    String s = (String)h2.get();
    h2.set(1); // Autoboxes to Integer
    Integer x = (Integer)h2.get();
  }
} ///:~