用法

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;

public class StaticMethod {

    public static void main(String[] args) {
        System.out.println(test("aaaaa"));  //aaaaa  基本用法
        System.out.println(test1("aa").get(0).equals("aa"));    //true  用於內部包裝
 

        System.out.println(test2(new HashSet(), Collection.class).size());  //0 用於強制轉換型別
        System.out.println(test3("bbbbb")); //bbbbb   裝神弄鬼
    }

    public static<T> T test(T obj){
        return obj;
    }

    public static<T> List<T> test1(T obj){
        List<T> list = new
 
 ArrayList();
        list.add(obj);
        return list;
    }

    public static<T> T test2(Object str, Class<T> obj){
        return (T)str;
    }

    public static<T, A, B, C, D> B test3(B obj){
        return obj;
    }

}