您可以：
<T>
从TSTNode
（即，使其成为非泛型的）中移除类型参数-仍然可以访问external<T>
。将
<T>
class中的type参数重命名TSTNode
为（say）U
。
[更新]
下面是四种重写代码的方法。它们全部编译。我认为您应该考虑使用的用法
EnumMap（请参见下面的版本4）。
版本1 ：在内部类中使用不同名称的type参数。您需要使用列表而不是数组。
public class TernarySearchTree<T> { protected class TSTNode<U> { // index values for accessing relatives array: protected static final int PARENT = 0, LOKID = 1, EQKID = 2, HIKID = 3; protected char splitchar; protected List<TSTNode<U>> relatives; private U data; protected TSTNode(char splitchar, TSTNode<U> parent) { this.splitchar = splitchar; relatives = new ArrayList<TSTNode<U>>(); for (int i = 0; i < HIKID; ++i) { // Allocate 4 slots in relatives relatives.add(null); } relatives.set(PARENT, parent); } } private TSTNode<T> node; // When you use it, pass T as U public TernarySearchTree() { node = new TSTNode<T>(',', null); // When you use it, pass T as U } }版本2 ：从封闭类继承T
public class TernarySearchTree<T> { protected class TSTNode { // index values for accessing relatives array: protected static final int PARENT = 0, LOKID = 1, EQKID = 2, HIKID = 3; protected char splitchar; protected List<TSTNode> relatives; private T data; protected TSTNode(char splitchar, TSTNode parent) { this.splitchar = splitchar; relatives = new ArrayList<TSTNode>(); for (int i = 0; i < HIKID; ++i) { // Allocate 4 slots in relatives relatives.add(null); } relatives.set(PARENT, parent); } } private TSTNode node; public TernarySearchTree() { node = new TSTNode(',', null); } }版本3 ：使用地图（而不是列表）
public class TernarySearchTree<T> { protected class TSTNode { // index values for accessing relatives array: protected static final int PARENT = 0, LOKID = 1, EQKID = 2, HIKID = 3; protected char splitchar; protected Map<Integer, TSTNode> relatives; private T data; protected TSTNode(char splitchar, TSTNode parent) { this.splitchar = splitchar; // Create a hash map. No need to pre-allocate! relatives = new HashMap<Integer, TSTNode>(); relatives.put(PARENT, parent); // set -> put } } private TSTNode node; public TernarySearchTree() { node = new TSTNode(',', null); } }}版本4 ：将索引定义为枚举+使用EnunMap（而不是哈希图）
public class TernarySearchTree<T> { protected static enum Index { PARENT, LOKID, EQKID, HIKID; } protected class TSTNode { protected char splitchar; protected EnumMap<Index, TSTNode> relatives; private T data; protected TSTNode(char splitchar, TSTNode parent) { this.splitchar = splitchar; // Create an EnumMap. relatives = new EnumMap<Index, TSTNode>(Index.class); relatives.put(Index.PARENT, parent); } } private TSTNode node; public TernarySearchTree() { node = new TSTNode(',', null); } }[更新2] 要记住的一件事：使用EnumMap代替顺序索引
