Question

我正在尝试显示背景图像，但它无法正常工作，我已经尝试了多次回复此错误的事情。每次它说复制字段我都不知道这意味着我是java的初学者

这是错误

Exception in thread "main" java.lang.ClassFormatError: Duplicate field        name&signature in class file search/text/file/SearchTextFile$1
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at search.text.file.SearchTextFile.<init>(SearchTextFile.java:46)
at search.text.file.SearchTextFile.main(SearchTextFile.java:42)
Java Result: 1

此尝试阻止导致背景错误：

    try {            
    BufferedImage img = ImageIO.read(new File("bible.jpg"));
    } catch(IOException e ) {

    }

谢谢

Java代码： package search.text.file;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.Insets;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import javax.imageio.ImageIO;
import javax.swing.DefaultListCellRenderer;
import javax.swing.DefaultListModel;
import javax.swing.ImageIcon;
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 SearchTextFile {

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

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


            JFrame frame = new JFrame("Bible Search");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setLayout(new BorderLayout());
            frame.add(new TestPane());
            frame.pack();
            frame.setLocationRelativeTo(null);
            frame.setVisible(true);
        }
try {            
BufferedImage img = ImageIO.read(new File("bible.jpg"));
} catch(IOException e ) {
}
});


}

public class TestPane extends JPanel {

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

    private String searchPhrase;

    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<>();
        list = new JList(model);
        list.setCellRenderer(new HighlightListCellRenderer());
        add(new JScrollPane(list));

        ActionHandler handler = new ActionHandler();

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

        try (BufferedReader reader = new BufferedReader(new InputStreamReader(getClass().getResourceAsStream("bible.txt")))) {

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

        } catch (IOException exp) {

            exp.printStackTrace();

        }
    }

    public class ActionHandler implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            searchPhrase = findText.getText();
            if (searchPhrase != null && searchPhrase.trim().length() == 0) {
                searchPhrase = null;
            }
            list.repaint();
//              model.removeAllElements();
////                    BufferedReader reader = null;
//
//              String searchText = findText.getText();
//              try (BufferedReader reader = new BufferedReader(new     FileReader(new File("bible.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, "Something Went     Wrong", "Error", JOptionPane.ERROR_MESSAGE);
//
//              }
        }
    }

    public class HighlightListCellRenderer extends DefaultListCellRenderer {

        public final String WITH_DELIMITER = "((?<=%1$s)|(?=%1$s))";

        @Override
        public Component getListCellRendererComponent(JList<?> list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
            if (value instanceof String && searchPhrase != null) {
                String text = (String) value;
                if (text.contains(searchPhrase)) {
                    text = text.replace(" ", "&nbsp;");
                    value = "<html>" + text.replace(searchPhrase, "<span STYLE='background-color: #ffff00'>" + searchPhrase + "</span>") + "</html>";
                }
            }
            return super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus); //To change body of generated methods, choose Tools | Templates.
        }

    }
}
}

Answer 1

你的尝试阻止：

try {            
BufferedImage img = ImageIO.read(new File("bible.jpg"));
} catch(IOException e ) {
}
});

不在任何方法或构造函数之外，这是不允许的。我建议你

将其移至构造函数或方法中。
请勿忽略您正在执行的例外情况，因为这是非常危险的编码。至少打印出异常的堆栈跟踪。

另外，为什么你在阅读图像但却什么都不做呢？

e.g。

public class SearchTextFile2 {

    private static void createAndShowGui() {
        BufferedImage img = null;
        try {
            // better to get as a resource and not as a File
            img = ImageIO.read(new File("bible.jpg"));
        } catch (IOException e) {
            e.printStackTrace();
        }

        JFrame frame = new JFrame("SearchTextFile2");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(new TestPane(img)); // pass image into TestPane
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }
        });
    }

    // make TestPane a static inner class
    // have TestPane display image within its paintComponent method
    public static class TestPane extends JPanel {
        private JTextField findText;
        private JButton search;
        private DefaultListModel<String> model;
        private JList list;
        private BufferedImage img;
        private String searchPhrase;

        public TestPane(BufferedImage img) {
            setLayout(new BorderLayout());
            this.img = img;
            // etc.....
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            if (img != null) {
                g.drawImage(img, 0, 0, this);
            }
        }
        // .....

Answer 2

看起来你放在一个文件中的所有类可能会在你的情况下被搞乱请检查java文档是否有错误

Java虚拟机尝试读取类文件并确定它文件格式错误或无法解释为类文件

http://docs.oracle.com/javase/7/docs/api/java/lang/ClassFormatError.html

为什么JFrame背景图像不起作用？

2 个答案: