有没有人知道如何搜索文本文件并在 JComponent(如 JPanel)中列出结果。

两天来我一直在努力解决这个问题，但如果没有成功，我将不胜感激。非常感谢。

我一直在尝试编写一个类来处理对文本文件的搜索查询。我的主要目标是获取包含在 JTextField 中输入的搜索关键字的文本文件中的行，并将它们打印在适当的 JComponent(类似于 JTextField、JTextPane，以最适用的为准)中。

我希望搜索结果显示在列中，就像 google 搜索结果的显示方式一样，以便文本文件中的每一行都打印在自己的行中。有人告诉我最好使用 ArrayList。我真的不知道该怎么做。我从各地收集了一些想法，这就是我目前所拥有的:

提前致谢。我对 Java 很陌生。我一整天都在努力做到这一点，但并没有走得太远。我愿意尝试提供的任何东西，甚至是新方法。

// The class that handles the search query
// Notice that I've commented out some parts that show errors

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.swing.JTextPane;


public class Search {

    public static String path;
    public static String qri;

    public Search(String dTestFileDAT, String qry) {
        path = dTestFileDAT;
        qri = qry;
    }

    public static JTextPane resultJTextPane;
    public static List<String> linesToPresent = new ArrayList<String>();

    public static List<String> searchFile(String path, String match){

        File f = new File(path);
        FileReader fr;
        try {
            fr = new FileReader(f);
            BufferedReader br = new BufferedReader(fr);
            String line;
                do{
                    line = br.readLine();
                    Pattern p = Pattern.compile(match);
                    Matcher m = p.matcher(line);
                    if(m.find())
                        linesToPresent.add(line);
                } while(line != null);

                br.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        // resultJTextPane = new JTextPane();
        // resultJTextPane = (JTextPane) Home.BulletinsJPanel.add(linesToPresent);

        return linesToPresent;
    }
}

// This handles the click event to take the query. Notice that I've commented out some parts that show errors
private void mouseClickedSearch(java.awt.event.MouseEvent evt) {
    Search fs = new Search("/D:/TestFile.dat/", "Text to search for");

    // searchResultsJPanel.add(Search.searchFile("/D:/TestFile.dat/", "COLE"));
    // searchResultsJTextField.add(fs);
}

最佳答案

有很多可能的解决方案，这只是一个简单的解决方案(不是认真的，它是 ;))

基本上，这只是使用一个 JList 来存储搜索文件中搜索文本的所有匹配项。

这是一个区分大小写的搜索，所以要小心

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class MySearch {

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

    public MySearch() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private JTextField findText;
        private JButton search;
        private DefaultListModel<String> model;

        public TestPane() {
            setLayout(new BorderLayout());
            JPanel searchPane = new JPanel(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.insets = new Insets(2, 2, 2, 2);
            searchPane.add(new JLabel("Find: "), gbc);
            gbc.gridx++;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.weightx = 1;
            findText = new JTextField(20);
            searchPane.add(findText, gbc);

            gbc.gridx++;
            gbc.fill = GridBagConstraints.NONE;
            gbc.weightx = 0;
            search = new JButton("Search");
            searchPane.add(search, gbc);

            add(searchPane, BorderLayout.NORTH);

            model = new DefaultListModel<>();
            JList list = new JList(model);
            add(new JScrollPane(list));

            ActionHandler handler = new ActionHandler();

            search.addActionListener(handler);
            findText.addActionListener(handler);
        }

        public class ActionHandler implements ActionListener {

            @Override
            public void actionPerformed(ActionEvent e) {
                model.removeAllElements();
//                    BufferedReader reader = null;

                String searchText = findText.getText();
                try (BufferedReader reader = new BufferedReader(new FileReader(new File("search.txt")))) {

                    String text = null;
                    while ((text = reader.readLine()) != null) {

                        if (text.contains(searchText)) {

                            model.addElement(text);

                        }

                    }

                } catch (IOException exp) {

                    exp.printStackTrace();
                    JOptionPane.showMessageDialog(TestPane.this, "Could not create file", "Error", JOptionPane.ERROR_MESSAGE);

                }
            }
        }
    }
}

您还可以采取另一种策略，只需突出显示匹配...

由于它是交互式的，因此使用的方法略有不同。基本上您只需键入，等待 0/4 秒，它就会开始搜索...

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;

public class MySearch02 {

    public static void main(String[] args) {
        new MySearch02();
    }

    public MySearch02() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private JTextField findText;
        private JTextArea ta;
        private Timer keyTimer;

        public TestPane() {
            setLayout(new BorderLayout());
            JPanel searchPane = new JPanel(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.insets = new Insets(2, 2, 2, 2);
            searchPane.add(new JLabel("Find: "), gbc);
            gbc.gridx++;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.weightx = 1;
            findText = new JTextField(20);
            searchPane.add(findText, gbc);

            add(searchPane, BorderLayout.NORTH);

            ta = new JTextArea(20, 40);
            ta.setWrapStyleWord(true);
            ta.setLineWrap(true);
            ta.setEditable(false);
            add(new JScrollPane(ta));

            loadFile();

            keyTimer = new Timer(250, new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    String find = findText.getText();
                    Document document = ta.getDocument();
                    try {
                        for (int index = 0; index + find.length() < document.getLength(); index++) {
                            String match = document.getText(index, find.length());
                            if (find.equals(match)) {
                                javax.swing.text.DefaultHighlighter.DefaultHighlightPainter highlightPainter =
                                        new javax.swing.text.DefaultHighlighter.DefaultHighlightPainter(Color.YELLOW);
                                ta.getHighlighter().addHighlight(index, index + find.length(),
                                        highlightPainter);
                            }
                        }
                    } catch (BadLocationException exp) {
                        exp.printStackTrace();
                    }
                }
            });
            keyTimer.setRepeats(false);

            findText.getDocument().addDocumentListener(new DocumentListener() {
                @Override
                public void insertUpdate(DocumentEvent e) {
                    keyTimer.restart();
                }

                @Override
                public void removeUpdate(DocumentEvent e) {
                    keyTimer.restart();
                }

                @Override
                public void changedUpdate(DocumentEvent e) {
                    keyTimer.restart();
                }
            });
        }

        protected void loadFile() {
            String searchText = findText.getText();
            try (BufferedReader reader = new BufferedReader(new FileReader(new File("search.txt")))) {
                ta.read(reader, "Text");
            } catch (IOException exp) {
                exp.printStackTrace();
                JOptionPane.showMessageDialog(TestPane.this, "Could not create file", "Error", JOptionPane.ERROR_MESSAGE);
            }
            ta.setCaretPosition(0);
        }
    }
}

关于java - 搜索文本文件并在 JPanel 中显示结果，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/17985808/