Java 一般静态工厂法问题
我的课程如下:Java 一般静态工厂法问题,java,eclipse,generics,netbeans,Java,Eclipse,Generics,Netbeans,我的课程如下: public class Tree<T extends Comparable<? super T>> { // private data omitted private Tree() {} // non parametric private constructor, not exposed // static factory method public static <T extends Comparable<? super T
public class Tree<T extends Comparable<? super T>> {
// private data omitted
private Tree() {} // non parametric private constructor, not exposed
// static factory method
public static <T extends Comparable<? super T>> Tree<T> newInstance() {
return new Tree<T>();
}
}
public类树BalusC注释-javac错误
通过显式键入解决:
Tree<Integer> tree = Tree.<Integer>newInstance();
Tree-Tree=Tree.newInstance();
。它是javac中的一个。顺便说一下,您忘记了newInstance()
方法中的static
。您不能将该方法编写为public static Tree newInstance()
,它将自动从类声明中填充t
?
public void test() {
Tree<Integer> tree = new Tree<Integer>();
}
Incompatibile types:
required: structures.trees.Tree<java.lang.Integer>
found: <T>structures.trees.Tree<T>
Tree<Integer> tree = Tree.<Integer>newInstance();