<T extends Object> public void PrintList(Collection<T> coll)
{
Iterator<T> it = coll.iterator();
while(it.hasNext())
{
System.out.println(it.next().toString());
}
}
上述代码编译时报错:非法的类型开始
<T extends Object> public void PrintList(Collection<T> coll)请问高手,如何解决?
{
Iterator<T> it = coll.iterator();
while(it.hasNext())
{
System.out.println(it.next().toString());
}
}
上述代码编译时报错:非法的类型开始
<T extends Object> public void PrintList(Collection<T> coll)请问高手,如何解决?
class Print<T extends Collection>{
public void PrintList(T coll)
{
Iterator it = coll.iterator();
while(it.hasNext())
{
System.out.println(it.next().toString());
}
}
}
我对泛型还了解不透彻,也看不出楼主要实现什么功能,但是在一个方法前面加那样的限定词显然是错误的。
import java.util.*;class PrintList<T extends Collection> {
public void PrintLists(T coll) {
Iterator it = coll.iterator();
while (it.hasNext()) {
System.out.println(it.next().toString());
}
}
}
哈哈,今天终于学了点东西。
参考:
http://blog.csdn.net/vbscript1981/archive/2005/04/20/355308.aspx
http://www-128.ibm.com/developerworks/cn/java/j-jtp01255.html?ca=dwcn-newsletter-java
import java.util.*;public class GenericTest_2
{
public static <T extends Object> ArrayList<T> CreateList()
{
ArrayList<T> myList = new ArrayList<T>();
//myList.add(new T());
return myList;
}
public static <T extends Object> void PrintList(Collection<T> coll)
{
System.out.println("The collection has " + coll.size() + " elements");
Iterator<T> it = coll.iterator();
T ele;
while(it.hasNext())
{
ele = it.next();
System.out.println("Emelent type:" + ele.getClass() + "\tElement value:" + ele);
}
}
public static void main(String strArgs[])
{
System.out.println("This program has no generic element!");
ArrayList<String> arr = GenericTest_2.CreateList();
arr.add("Hello");
//arr.add(2);
GenericTest_2.PrintList(arr);
}
}
D:\e168\WEB-INF\src>javac -d ..\classes cn\tedeyang\test\*.java
cn\tedeyang\test\GenericTest_2.java:6: illegal start of type
public static <T extends Object> ArrayList<T> CreateList()
^
cn\tedeyang\test\GenericTest_2.java:33: <identifier> expected
}
^
2 errors