/*
泛型:指定集合类型,在运行而不是编译时时就发现问题,消除安全隐患。避免强转。
*/
package pack;
import java.util.ArrayList;
import java.util.Iterator;
/*public class Main {
public static void sys(Object obj) {
System.out.println(obj);
}
public static void main(String[] args) {
TreeSet<String> al = new TreeSet<String>(new MyComparator()); //集合泛型
al.add("aa");
al.add("bbb");
al.add("c");
Iterator<String> it = al.iterator();
while(it.hasNext()) {
String s = (String)it.next(); //避免强转
sys(s);
sys(it.next());
}
}
}
class MyComparator implements Comparator<String> {
public int compare(String o1,String o2) {