Java动态JTree
我想找到一种动态地将节点添加到JTree的方法,查看文档和示例,这只能在JTree的构造函数中完成 如果可能,请向我展示执行此操作的代码片段 提前谢谢。试试看 编辑并提供更多说明:您希望树模型基于。上面的链接是Sun教程中的一个示例。试试看Java动态JTree,java,swing,Java,Swing,我想找到一种动态地将节点添加到JTree的方法,查看文档和示例,这只能在JTree的构造函数中完成 如果可能,请向我展示执行此操作的代码片段 提前谢谢。试试看 编辑并提供更多说明:您希望树模型基于。上面的链接是Sun教程中的一个示例。试试看 编辑并提供更多说明:您希望树模型基于。上面的链接是Sun教程中的一个示例。您需要一个TreeModel和TreeNode的自定义实现,请参见下文。只需扩展LazyTreeModel并实现loadChildren() 您必须用实现替换几个依赖项:LOG-you
编辑并提供更多说明:您希望树模型基于。上面的链接是Sun教程中的一个示例。您需要一个TreeModel和TreeNode的自定义实现,请参见下文。只需扩展LazyTreeModel并实现loadChildren() 您必须用实现替换几个依赖项:LOG-yourlogger 和WorkerManager.getInstance().schedule(new LoadNodesWorker())您可以用线程()替换它-Worker相当于Runnable
public abstract class LazyTreeModel extends DefaultTreeModel implements TreeWillExpandListener {
public LazyTreeModel(TreeNode root, JTree tree) {
super(root);
setAsksAllowsChildren(true);
tree.addTreeWillExpandListener(this);
tree.setModel(this);
}
public void treeWillExpand(TreeExpansionEvent event) throws ExpandVetoException {
LazyTreeNode node = (LazyTreeNode) event.getPath().getLastPathComponent();
if (node.isLoaded()) {
return;
}
setLoading(node, false);
WorkerManager.getInstance().schedule(new LoadNodesWorker(node));
}
public void reloadNode(String id) {
LazyTreeNode node = findNode(id);
if (node != null) {
node.setLoaded(false);
setLoading(node, true);
WorkerManager.getInstance().schedule(new LoadNodesWorker(node));
}
}
public void reloadParentNode(String id) {
LazyTreeNode node = findParent(id);
if (node != null) {
node.setLoaded(false);
setLoading(node, true);
WorkerManager.getInstance().schedule(new LoadNodesWorker(node));
}
}
public LazyTreeNode findParent(String id) {
LazyTreeNode node = findNode(id);
if (node != null && node.getParent() != null) {
return (LazyTreeNode) node.getParent();
}
return null;
}
public void loadFirstLevel() {
setLoading((LazyTreeNode) getRoot(), false);
WorkerManager.getInstance().schedule(new LoadNodesWorker((LazyTreeNode) getRoot()));
}
public void treeWillCollapse(TreeExpansionEvent event) throws ExpandVetoException {
}
protected void setChildren(LazyTreeNode parentNode, LazyTreeNode... nodes) {
if (nodes == null) {
return;
}
int childCount = parentNode.getChildCount();
if (childCount > 0) {
for (int i = 0; i < childCount; i++) {
removeNodeFromParent((MutableTreeNode) parentNode.getChildAt(0));
}
}
for (int i = 0; i < nodes.length; i++) {
insertNodeInto(nodes[i], parentNode, i);
}
}
private void setLoading2(final LazyTreeNode parentNode, final boolean reload) {
if (reload) {
setChildren(parentNode, createReloadingNode());
} else {
setChildren(parentNode, createLoadingNode());
}
}
private void setLoading(final LazyTreeNode parentNode, final boolean reload) {
if (SwingUtilities.isEventDispatchThread()) {
setLoading2(parentNode, reload);
} else {
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
setLoading2(parentNode, reload);
}
});
} catch (Exception e) {
LOG.error("Cannot create loading node", e);
}
}
}
private LazyTreeNode findNode(String id) {
return findNode(id, (LazyTreeNode) getRoot());
}
private LazyTreeNode findNode(String id, LazyTreeNode parent) {
int count = parent.getChildCount();
for (int i = 0; i < count; i++) {
LazyTreeNode node = (LazyTreeNode) parent.getChildAt(i);
if (id.equals(node.getId())) {
return node;
}
if (node.isLoaded()) {
node = findNode(id, node);
if (node != null) {
return node;
}
}
}
return null;
}
public abstract LazyTreeNode[] loadChildren(LazyTreeNode parentNode);
protected LazyTreeNode createLoadingNode() {
return new LazyTreeNode(null, "Loading...", false);
}
protected LazyTreeNode createReloadingNode() {
return new LazyTreeNode(null, "Refreshing...", false);
}
class LoadNodesWorker implements Worker {
private LazyTreeNode parentNode;
LoadNodesWorker(LazyTreeNode parent) {
this.parentNode = parent;
}
public String getName() {
return "Lazy loading of node " + parentNode.getId();
}
public void execute() throws Exception {
final LazyTreeNode[] treeNodes = loadChildren(parentNode);
if (treeNodes == null) {
return;
}
SwingUtilities.invokeLater(new Runnable() {
public void run() {
parentNode.setLoaded(true);
setChildren(parentNode, treeNodes);
}
});
}
}
}您需要有树模型和树节点的自定义实现,请参见下文。只需扩展LazyTreeModel并实现loadChildren() 您必须用实现替换几个依赖项:LOG-yourlogger 和WorkerManager.getInstance().schedule(new LoadNodesWorker())您可以用线程()替换它-Worker相当于Runnable
public abstract class LazyTreeModel extends DefaultTreeModel implements TreeWillExpandListener {
public LazyTreeModel(TreeNode root, JTree tree) {
super(root);
setAsksAllowsChildren(true);
tree.addTreeWillExpandListener(this);
tree.setModel(this);
}
public void treeWillExpand(TreeExpansionEvent event) throws ExpandVetoException {
LazyTreeNode node = (LazyTreeNode) event.getPath().getLastPathComponent();
if (node.isLoaded()) {
return;
}
setLoading(node, false);
WorkerManager.getInstance().schedule(new LoadNodesWorker(node));
}
public void reloadNode(String id) {
LazyTreeNode node = findNode(id);
if (node != null) {
node.setLoaded(false);
setLoading(node, true);
WorkerManager.getInstance().schedule(new LoadNodesWorker(node));
}
}
public void reloadParentNode(String id) {
LazyTreeNode node = findParent(id);
if (node != null) {
node.setLoaded(false);
setLoading(node, true);
WorkerManager.getInstance().schedule(new LoadNodesWorker(node));
}
}
public LazyTreeNode findParent(String id) {
LazyTreeNode node = findNode(id);
if (node != null && node.getParent() != null) {
return (LazyTreeNode) node.getParent();
}
return null;
}
public void loadFirstLevel() {
setLoading((LazyTreeNode) getRoot(), false);
WorkerManager.getInstance().schedule(new LoadNodesWorker((LazyTreeNode) getRoot()));
}
public void treeWillCollapse(TreeExpansionEvent event) throws ExpandVetoException {
}
protected void setChildren(LazyTreeNode parentNode, LazyTreeNode... nodes) {
if (nodes == null) {
return;
}
int childCount = parentNode.getChildCount();
if (childCount > 0) {
for (int i = 0; i < childCount; i++) {
removeNodeFromParent((MutableTreeNode) parentNode.getChildAt(0));
}
}
for (int i = 0; i < nodes.length; i++) {
insertNodeInto(nodes[i], parentNode, i);
}
}
private void setLoading2(final LazyTreeNode parentNode, final boolean reload) {
if (reload) {
setChildren(parentNode, createReloadingNode());
} else {
setChildren(parentNode, createLoadingNode());
}
}
private void setLoading(final LazyTreeNode parentNode, final boolean reload) {
if (SwingUtilities.isEventDispatchThread()) {
setLoading2(parentNode, reload);
} else {
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
setLoading2(parentNode, reload);
}
});
} catch (Exception e) {
LOG.error("Cannot create loading node", e);
}
}
}
private LazyTreeNode findNode(String id) {
return findNode(id, (LazyTreeNode) getRoot());
}
private LazyTreeNode findNode(String id, LazyTreeNode parent) {
int count = parent.getChildCount();
for (int i = 0; i < count; i++) {
LazyTreeNode node = (LazyTreeNode) parent.getChildAt(i);
if (id.equals(node.getId())) {
return node;
}
if (node.isLoaded()) {
node = findNode(id, node);
if (node != null) {
return node;
}
}
}
return null;
}
public abstract LazyTreeNode[] loadChildren(LazyTreeNode parentNode);
protected LazyTreeNode createLoadingNode() {
return new LazyTreeNode(null, "Loading...", false);
}
protected LazyTreeNode createReloadingNode() {
return new LazyTreeNode(null, "Refreshing...", false);
}
class LoadNodesWorker implements Worker {
private LazyTreeNode parentNode;
LoadNodesWorker(LazyTreeNode parent) {
this.parentNode = parent;
}
public String getName() {
return "Lazy loading of node " + parentNode.getId();
}
public void execute() throws Exception {
final LazyTreeNode[] treeNodes = loadChildren(parentNode);
if (treeNodes == null) {
return;
}
SwingUtilities.invokeLater(new Runnable() {
public void run() {
parentNode.setLoaded(true);
setChildren(parentNode, treeNodes);
}
});
}
}
}I82Much提到的Sun示例教程包括一个演示项目,它由两个源文件和。您应该可以通过这些链接访问它们。I82Much提到的Sun示例教程包括一个演示项目,该项目由两个源文件和一个示例文件组成。您应该可以通过这些链接访问它们。我看到了这个示例,但我找不到它的源代码,也不知道如何设置根节点或在运行时让根节点使用它。谢谢你的关注。我看到了这个示例,但是我找不到它的源代码,也不知道如何设置根节点或在运行时让根节点使用它。感谢您的关注。您不能动态地将节点添加到JTree,因为JTree是视图部分,而不是模型部分。您需要分离并跟踪您的模型(Adrian发布了一个很好的模型供您使用),然后您可以将节点动态添加到您的模型中。您不能将节点动态添加到JTree中,因为JTree是视图部分,而不是模型部分。您需要分离并跟踪您的模型(Adrian发布了一个好的模型供您使用),然后您可以动态地将节点添加到您的模型中。