在class Tree
我得到错误消息:调用由实例名实例方法为字符串在Java
方法removeparent()是未定义String类型。
我想转换字符串“Grandchild3”反对哪个实例MyTreeNode类的话,我可以用removep("Grandchild3")
通话这样Grandchild3.removeparent()
的方法。
我该怎么做?
这里的类MyTreeNode:
public class MyTreeNode<T>{
private T data = null;
private List<MyTreeNode> children = new ArrayList<>();
private MyTreeNode parent = null;
public MyTreeNode(T data) {
this.data = data;
}
public void addChild(MyTreeNode child) {
child.setParent(this);
this.children.add(child);
}
public void addChild(T data) {
MyTreeNode<T> newChild = new MyTreeNode<>(data);
newChild.setParent(this);
children.add(newChild);
}
public void addChildren(List<MyTreeNode> children) {
for(MyTreeNode t : children) {
t.setParent(this);
}
this.children.addAll(children);
}
public List<MyTreeNode> getChildren() {
return children;
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
private void setParent(MyTreeNode parent) {
this.parent = parent;
}
public MyTreeNode getParent() {
return parent;
}
public void removeparent() {
this.parent = null;
}
public void removeChild(MyTreeNode<T> child)
{
this.children.remove(child);
}
}
这里的类树:
public class Tree {
public static void main(String[] args) throws ClassNotFoundException {
// TODO Auto-generated method stub
MyTreeNode<String> root = new MyTreeNode<>("Root");
MyTreeNode<String> child1 = new MyTreeNode<>("Child1");
child1.addChild("Grandchild1");
child1.addChild("Grandchild2");
MyTreeNode<String> child2 = new MyTreeNode<>("Child2");
child2.addChild("Grandchild3");
root.addChild(child1);
root.addChild(child2);
root.addChild("Child3");
root.addChildren(Arrays.asList(
new MyTreeNode<>("Child4"),
new MyTreeNode<>("Child5"),
new MyTreeNode<>("Child6")
));
for(MyTreeNode<String> node : root.getChildren()) {
System.out.println(node.getData());
}
printTree(root, " ");
removep("Grandchild3"); //error message"The method removeparent() is undefined for the type String"
printTree(root, " ");
}
private static void printTree(MyTreeNode<String> node, String appender) {
System.out.println(appender+node.getData());
for (MyTreeNode each : node.getChildren()){
printTree(each, appender + appender);
}
}
public static void removep(MyTreeNode<String> node)
{
node.getParent().removeChild(node);
node.removeparent();
}
}
'removep'有一个'MyTreeNode'类型的参数。你在'removep(“Grandchild3”);''行中传递一个字符串。 'String'与'MyTreeNode '不一样。 –
@TT是的,这是我的问题。如何弄清楚? – lvanna9786
只是猜测:调用'removep(new MyTreeNode <>(“Grandchild3”));'? –