Java泛型小记

泛型可以把运行期的错误提前到编译期进行检查并排除

package Object_Oriented;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;





public class G_I implements Generic {
    @Override
    public void Method(String s) {
        ArrayList arr1 = new ArrayList<>();
        arr1.add(1);
        arr1.add(2);
        arr1.add(3);
        ArrayList arr2 = new ArrayList<>();
        arr2.add("Bill");
        arr2.add("Lily");
        arr2.add("Leo");
        print_coll(arr1);
        print_coll(arr2);
    }
    public static void print_coll(ArrayList arrayList){
        Iterator iterator = arrayList.iterator();
        while (iterator.hasNext()){
            Object obj = iterator.next();
            System.out.println(obj);
        }
    }

    public static void main(String[] args) {
        new G_I().Method("Hello");
    }
}