java迭代器PECS

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//PECS:producer-extends-comsumer-super
import com.google.common.collect.Lists;import java.util.Arrays;import java.util.List;/** * Created by jianjun.yu on 15-4-21. */public class GTest {    public static void main(String[] args) {        List<Integer> ints = Arrays.asList(1, 2, 3);        filterObject(ints);        List<Number> objs = Arrays.<Number>asList(1f, 1, 2l);        filterObject(objs);        List<Integer> il = Lists.newArrayList();        getObject(il);        List<Number> nl = Lists.newArrayList();        getObject(nl);    }    public static <T>void filterObject(Iterable<? extends Number> list) {        for (Number t : list) {            if (t != null) {                System.out.println(t);            }        }    }    public static <T>void getObject(List<? super Integer> list) {        for (int i = 0; i < 10; i++) {            list.add(i);        }    }    //PECS:producer-extends-comsumer-super}

java迭代器PECS