JavaFX and Lucene

Question

我正在创建一个搜索引擎类型的项目，我必须在JavaFX中创建一个UI，并使用ApacheLucene进行查询。我所处的阶段是，JavaFX中的UI本身可以完美地工作(不调用任何Lucene方法(，Lucene的查询本身也可以很好地工作(在一个单独的java项目中(。当我试图通过在按下ENTER按钮时执行的操作中创建一个Lucene对象来将两者结合起来时，它会崩溃，异常一点也不令人困惑。

我正在为我的Window和LuceneTester类以及抛出的异常提供代码。

主要类别：

public class Main extends Application {

@Override
public void start(Stage primaryStage) {
new Window(primaryStage);
}

public static void main(String[] args) {
launch(args);
}
}

窗口类

public class Window{
public Window(Stage primaryStage) {
VBox root = new VBox();
root.getChildren().addAll(setSearch(), setBody());

Scene scene = new Scene(root);
primaryStage.setTitle("The Reuters Search Assistant");
primaryStage.getIcons().add(new Image(getClass().getResourceAsStream("icon.png")));
primaryStage.requestFocus();
primaryStage.setMinWidth(1280);
primaryStage.setMinHeight(720);
primaryStage.setResizable(false);
primaryStage.setScene(scene);
primaryStage.show();
}

private VBox setSearch() {
Label search = new Label("Search");
search.setFont(new Font("arial", 30));
search.setPadding(new Insets(5.0, 5.0, 5.0, 5.0));
search.setAlignment(Pos.CENTER_LEFT);
search.setTextAlignment(TextAlignment.LEFT);

TextField searchBar = new TextField();
searchBar.setFont(new Font("arial", 14));
searchBar.setPromptText("type here");
searchBar.setAlignment(Pos.CENTER_LEFT);
searchBar.setOnKeyPressed(event -> {
if (event.getCode() == KeyCode.ENTER) {
searchAction(searchBar.getText());
}
});

Separator separator = new Separator();
separator.setOrientation(Orientation.HORIZONTAL);
separator.setPadding(new Insets(5.0, 0, 0, 0));

VBox searchPanel = new VBox();
searchPanel.setAlignment(Pos.TOP_LEFT);
searchPanel.setPadding(new Insets(5.0, 5.0, 0 ,5.0));
searchPanel.setSpacing(5.0);
searchPanel.fillWidthProperty();
searchPanel.getChildren().addAll(search, searchBar, separator);
return searchPanel;
}

private HBox setBody() {
Button addBtn = new Button("Add Article");
addBtn.setFont(new Font("arial", 20));
addBtn.setMinWidth(170);
addBtn.setOnMouseClicked(e -> {
addArticleAction();
});

Button editBtn = new Button("Edit Article");
editBtn.setFont(new Font("arial", 20));
editBtn.setMinWidth(170);
editBtn.setOnMouseClicked(e -> {
editArticleAction();
});

Button delBtn = new Button("Delete Article");
delBtn.setFont(new Font("arial", 20));
delBtn.setMinWidth(170);
delBtn.setOnMouseClicked(e -> {
delArticleAction();
});

VBox buttonsBox = new VBox();
buttonsBox.setAlignment(Pos.TOP_CENTER);
buttonsBox.setMinWidth(200);
buttonsBox.setPadding(new Insets(15.0, 5.0, 5.0, 5.0));
buttonsBox.setSpacing(20.0);
buttonsBox.getChildren().addAll(addBtn, editBtn, delBtn);

Separator separator = new Separator();
separator.setOrientation(Orientation.VERTICAL);

ListView listView = new ListView();
listView.setMinWidth(1050);
listView.setMinHeight(574);

VBox listViewBox = new VBox();
listViewBox.setPadding(new Insets(5.0, 0, 0, 1.0));
listViewBox.getChildren().add(listView);

HBox bodyPanel = new HBox();
bodyPanel.getChildren().addAll(buttonsBox, separator, listViewBox);
return bodyPanel;
}

private void searchAction(String searchString) {
System.out.println("Searching for : " + searchString);
// Here is where the exception occurs.
LuceneTester search = new LuceneTester(searchString);
}

private void addArticleAction() {
System.out.println("add article");
}

private void editArticleAction() {
System.out.println("edit article");
}

private void delArticleAction() {
System.out.println("delete article");
}
}

LuceneEster类

public class LuceneTester {

String indexDir = "C:\Users\stefa\eclipse-workspace\TReSA\index";
String dataDir = "C:\Users\stefa\eclipse-workspace\TReSA\data";
Indexer indexer;
Searcher searcher;

public LuceneTester(String searchString) {
try {
this.createIndex();
this.search(searchString);
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
}
}

private void createIndex() throws IOException {
indexer = new Indexer(indexDir);
int numIndexed;
long startTime = System.currentTimeMillis();
numIndexed = indexer.createIndex(dataDir, new TextFileFilter());
long endTime = System.currentTimeMillis();
indexer.close();
System.out.println(numIndexed + " File(s) indexed, time taken: " + (endTime-startTime) + " ms");
}

private void search(String searchQuery) throws IOException, ParseException {
searcher = new Searcher(indexDir);
long startTime = System.currentTimeMillis();
TopDocs hits = searcher.search(searchQuery);
long endTime = System.currentTimeMillis();
System.out.println(hits.totalHits +" found. Time : " + (endTime - startTime) + " ms");
for(ScoreDoc scoreDoc : hits.scoreDocs) {
Document doc = searcher.getDocument(scoreDoc);
System.out.println("File: " + doc.get(LuceneConstants.FILE_PATH));
}
}
}

异常

Exception in thread "JavaFX Application Thread" java.lang.NoClassDefFoundError: org/apache/lucene/queryparser/classic/ParseException
at com.TReSA.main.Window.searchAction(Window.java:116)
at com.TReSA.main.Window.lambda$0(Window.java:52)
at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:234)
at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.base/javafx.event.Event.fireEvent(Event.java:198)
at javafx.graphics/javafx.scene.Scene$KeyHandler.process(Scene.java:4105)
at javafx.graphics/javafx.scene.Scene.processKeyEvent(Scene.java:2156)
at javafx.graphics/javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:2630)
at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:218)
at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:150)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$1(GlassViewEventHandler.java:250)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:424)
at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:249)
at javafx.graphics/com.sun.glass.ui.View.handleKeyEvent(View.java:548)
at javafx.graphics/com.sun.glass.ui.View.notifyKey(View.java:972)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:184)
at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.ClassNotFoundException: org.apache.lucene.queryparser.classic.ParseException
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
... 29 more

提前谢谢。

Answer 1

ClassNotFoundException: org.apache.lucene.queryparser.classic.ParseException意味着Lucene缺少依赖项，因此您应该检查构建工具的设置。

但这也意味着发生了异常，因此您可能需要仔细检查仅Lucene代码是否真的有效。