java - .setIcon() 导致 NullPointerException-6ren

java - .setIcon() 导致 NullPointerException

转载作者：行者123 更新时间：2023-12-02 05:59:01

我正在编写一个相当长的代码，它运行得非常好。它突然停止工作，我让其他人测试它并确认它对他们也不起作用。我还尝试回滚代码，甚至几天前也没有任何变化。我放置了一堆 System.out.Println() 来帮助我调试代码损坏的位置以及接收 NullPointerException 的位置。它发生在 initComponents() 处。更奇怪的是，当我使用 GUI Builder 时，initComponenets 中的任何内容都是使用 NetBeans 生成的。我有 15 行名为“Alive #”，这样我就可以在程序崩溃时轻松地在日志中看到。《Alive 14》是我在崩溃前能看到的最后一个，《Alive 15》从未到达。我只能在下面放一个片段。 https://pastebin.com/ibPfDxMY具有完整的 initComponents()。更令人好奇的是，当从 NetBeans 运行它时，它可以一致地工作，只有当我通过双击或终端运行 .jar 文件时才会出现此错误。

我尝试运行一个空白测试框架，它运行得很好。


public class NewFrame extends javax.swing.JFrame {

    public NewFrame() throws IOException, NullPointerException{
        System.out.println("Alive 14");
        initComponents();
        System.out.println("Alive 15");
    }


 private void initComponents() {

        mainPane = new javax.swing.JPanel();
        headerPane = new javax.swing.JPanel();
        logoButton = new javax.swing.JButton();
        exitButton = new javax.swing.JButton();
        titleLabel = new javax.swing.JLabel();
        logoutButton = new javax.swing.JButton();
        PacketPane = new javax.swing.JTabbedPane();
        exploitPane = new javax.swing.JPanel();
        exploitScroll = new javax.swing.JScrollPane();
        exploitList = new javax.swing.JList<>();
        customPane = new javax.swing.JPanel();
        customFrame = new javax.swing.JPanel();
        customScroll = new javax.swing.JScrollPane();
        customList = new javax.swing.JList<>();
        builderPane = new javax.swing.JPanel();
        builderFrame = new javax.swing.JPanel();
        builderPlaceholder = new javax.swing.JLabel();
        InfoPane = new javax.swing.JTabbedPane();
        logPane = new javax.swing.JPanel();
        logScroll = new javax.swing.JScrollPane();
        logArea = new javax.swing.JTextPane();
        chartPane = new javax.swing.JPanel();
        chartScroll = new javax.swing.JScrollPane();
        chartTable = new javax.swing.JTable();
        monsterPane = new javax.swing.JPanel();
        monsterScroll = new javax.swing.JScrollPane();
        monsterTable = new javax.swing.JTable();
        inventoryPane = new javax.swing.JPanel();
        inventoryScroll = new javax.swing.JScrollPane();
        inventoryList = new javax.swing.JList<>();
        bankPane = new javax.swing.JPanel();
        bankScroll = new javax.swing.JScrollPane();
        bankList = new javax.swing.JList<>();
        infoPane = new javax.swing.JPanel();
        infoFrame = new javax.swing.JPanel();
        goldValue = new javax.swing.JLabel();
        acValue = new javax.swing.JLabel();
        areaIdValue = new javax.swing.JLabel();
        entValue = new javax.swing.JLabel();
        usernameValue = new javax.swing.JLabel();
        areaValue = new javax.swing.JLabel();
        playerCountValue = new javax.swing.JLabel();
        playerCountLabel = new javax.swing.JLabel();
        areaLabel = new javax.swing.JLabel();
        usernameLabel = new javax.swing.JLabel();
        entLabel = new javax.swing.JLabel();
        areaIdLabel = new javax.swing.JLabel();
        acLabel = new javax.swing.JLabel();
        goldLabel = new javax.swing.JLabel();
        togglePane = new javax.swing.JPanel();
        toggleFrame = new javax.swing.JPanel();
        afkButton = new javax.swing.JButton();
        followButton = new javax.swing.JButton();
        farmButton = new javax.swing.JButton();
        slideButton = new javax.swing.JButton();
        invisibleButton = new javax.swing.JButton();
        copyButton = new javax.swing.JButton();
        copyLabel = new javax.swing.JLabel();
        invisibleLabel = new javax.swing.JLabel();
        slideLabel = new javax.swing.JLabel();
        farmLabel = new javax.swing.JLabel();
        followLabel = new javax.swing.JLabel();
        afkLabel = new javax.swing.JLabel();
        afkValue = new javax.swing.JLabel();
        followValue = new javax.swing.JLabel();
        farmValue = new javax.swing.JLabel();
        slideValue = new javax.swing.JLabel();
        invisibleValue = new javax.swing.JLabel();
        copyValue = new javax.swing.JLabel();
        SettingsPane = new javax.swing.JPanel();
        settingsFrame = new javax.swing.JPanel();
        userLabel = new javax.swing.JLabel();
        emoteLabel = new javax.swing.JLabel();
        settingsSubmitButton = new javax.swing.JButton();
        delayLabel = new javax.swing.JLabel();
        loopLabel = new javax.swing.JLabel();
        settingsSpamButton = new javax.swing.JButton();
        emoteList = new javax.swing.JComboBox<>();
        loopField = new javax.swing.JTextField();
        userField = new javax.swing.JTextField();
        textField = new javax.swing.JTextField();
        textLabel = new javax.swing.JLabel();
        delayField = new javax.swing.JTextField();
        ChatPane = new javax.swing.JPanel();
        chatScroll = new javax.swing.JScrollPane();
        chatArea = new javax.swing.JTextPane();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setTitle("Yumemi");
        setUndecorated(true);

        mainPane.setBackground(new java.awt.Color(30, 30, 30));
        mainPane.setPreferredSize(new java.awt.Dimension(716, 567));
        mainPane.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
            public void mouseDragged(java.awt.event.MouseEvent evt) {
                mainPaneMouseDragged(evt);
            }
        });
        mainPane.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mousePressed(java.awt.event.MouseEvent evt) {
                mainPaneMousePressed(evt);
            }
        });

        headerPane.setBackground(new java.awt.Color(0, 0, 0));

        logoButton.setBackground(new java.awt.Color(0, 0, 0));
        logoButton.setFont(new java.awt.Font("Calibri", 0, 14)); // NOI18N
        logoButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/AQWBot/Icons/icon.png"))); // NOI18N
        logoButton.setBorder(null);
        logoButton.setBorderPainted(false);
        logoButton.setContentAreaFilled(false);
        logoButton.setDefaultCapable(false);
        logoButton.setFocusPainted(false);
        logoButton.setFocusable(false);
        logoButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
        logoButton.setIconTextGap(0);
        logoButton.setRequestFocusEnabled(false);
        logoButton.setVerifyInputWhenFocusTarget(false);
        logoButton.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
            public void mouseDragged(java.awt.event.MouseEvent evt) {
                logoButtonMouseDragged(evt);
            }
        });
        logoButton.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mousePressed(java.awt.event.MouseEvent evt) {
                logoButtonMousePressed(evt);
            }
        });

        exitButton.setBackground(new java.awt.Color(255, 0, 0));
        exitButton.setFont(new java.awt.Font("Calibri", 0, 14)); // NOI18N
        exitButton.setForeground(new java.awt.Color(255, 255, 255));
        exitButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/aqwbot/Icons/close.jpg"))); // NOI18N
        exitButton.setText("X");
        exitButton.setBorderPainted(false);
        exitButton.setContentAreaFilled(false);
        exitButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
        exitButton.setIconTextGap(0);
        exitButton.setPressedIcon(new javax.swing.ImageIcon(getClass().getResource("/aqwbot/Icons/close_clicked.jpg"))); // NOI18N
        exitButton.setRolloverIcon(new javax.swing.ImageIcon(getClass().getResource("/aqwbot/Icons/close_hover.jpg"))); // NOI18N
        exitButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                exitButtonActionPerformed(evt);
            }
        });

        titleLabel.setFont(new java.awt.Font("Calibri", 1, 14)); // NOI18N
        titleLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        titleLabel.setText("Yumemi");
        titleLabel.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
            public void mouseDragged(java.awt.event.MouseEvent evt) {
                titleLabelMouseDragged(evt);
            }
        });
        titleLabel.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mouseEntered(java.awt.event.MouseEvent evt) {
                titleLabelMouseEntered(evt);
            }
            public void mouseExited(java.awt.event.MouseEvent evt) {
                titleLabelMouseExited(evt);
            }
            public void mousePressed(java.awt.event.MouseEvent evt) {
                titleLabelMousePressed(evt);
            }
        });

        logoutButton.setBackground(new java.awt.Color(255, 102, 0));
        logoutButton.setFont(new java.awt.Font("Calibri", 0, 14)); // NOI18N
        logoutButton.setForeground(new java.awt.Color(255, 255, 255));
        logoutButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/aqwbot/Icons/logout.jpg"))); // NOI18N
        logoutButton.setText("L");
        logoutButton.setBorderPainted(false);
        logoutButton.setContentAreaFilled(false);
        logoutButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
        logoutButton.setIconTextGap(0);
        logoutButton.setPressedIcon(new javax.swing.ImageIcon(getClass().getResource("/aqwbot/Icons/logout_clicked.jpg"))); // NOI18N
        logoutButton.setRolloverIcon(new javax.swing.ImageIcon(getClass().getResource("/aqwbot/Icons/logout_hover.jpg"))); // NOI18N
        logoutButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                logoutButtonActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout headerPaneLayout = new javax.swing.GroupLayout(headerPane);
        headerPane.setLayout(headerPaneLayout);
        headerPaneLayout.setHorizontalGroup(
            headerPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(headerPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(logoButton)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(titleLabel, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(logoutButton, javax.swing.GroupLayout.PREFERRED_SIZE, 38, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(exitButton, javax.swing.GroupLayout.PREFERRED_SIZE, 38, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap())
        );
        headerPaneLayout.setVerticalGroup(
            headerPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(headerPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addGroup(headerPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(headerPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(exitButton, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(titleLabel, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(logoutButton, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addComponent(logoButton, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(0, 9, Short.MAX_VALUE))
        );

        exploitList.setModel(new javax.swing.AbstractListModel<String>() {
            String[] strings = { "Raw", "XP", "Say", "Whisper", "Role Play", "Emote", "", "Join", "Goto", "Move", "House", "", "Friend", "Follow", "Copy", "ID", "", "Party Chat", "Invite Party", "Remove Party", "Summon", "Promote", "Leave Party", "", "Guild Chat", "Create Guild", "Invite to Guild", "Remove from Guild", "Promote Guild", "Demote Guild", "Change MOTD", "Rename Guild", "", "Battle Commands", "", "Custom Commands", "Invisible", "Slide", "Farm", "Share Attack", "", "Staff Commands" };
            public int getSize() { return strings.length; }
            public String getElementAt(int i) { return strings[i]; }
        });
        exploitList.setSelectionMode(javax.swing.ListSelectionModel.SINGLE_SELECTION);
        exploitScroll.setViewportView(exploitList);

        javax.swing.GroupLayout exploitPaneLayout = new javax.swing.GroupLayout(exploitPane);
        exploitPane.setLayout(exploitPaneLayout);
        exploitPaneLayout.setHorizontalGroup(
            exploitPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(exploitPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(exploitScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 330, Short.MAX_VALUE)
                .addContainerGap())
        );
        exploitPaneLayout.setVerticalGroup(
            exploitPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, exploitPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(exploitScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 208, Short.MAX_VALUE)
                .addContainerGap())
        );

        PacketPane.addTab("Commands", exploitPane);

        customList.setModel(new javax.swing.AbstractListModel<String>() {
            String[] strings = { "Accept Quest", "AutoComplete Quest" };
            public int getSize() { return strings.length; }
            public String getElementAt(int i) { return strings[i]; }
        });
        customScroll.setViewportView(customList);

        javax.swing.GroupLayout customFrameLayout = new javax.swing.GroupLayout(customFrame);
        customFrame.setLayout(customFrameLayout);
        customFrameLayout.setHorizontalGroup(
            customFrameLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(customFrameLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(customScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 340, Short.MAX_VALUE)
                .addContainerGap())
        );
        customFrameLayout.setVerticalGroup(
            customFrameLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, customFrameLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(customScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 217, Short.MAX_VALUE)
                .addContainerGap())
        );

        javax.swing.GroupLayout customPaneLayout = new javax.swing.GroupLayout(customPane);
        customPane.setLayout(customPaneLayout);
        customPaneLayout.setHorizontalGroup(
            customPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 360, Short.MAX_VALUE)
            .addGroup(customPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(customPaneLayout.createSequentialGroup()
                    .addGap(0, 0, Short.MAX_VALUE)
                    .addComponent(customFrame, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(0, 0, Short.MAX_VALUE)))
        );
        customPaneLayout.setVerticalGroup(
            customPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 229, Short.MAX_VALUE)
            .addGroup(customPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(customPaneLayout.createSequentialGroup()
                    .addGap(0, 0, Short.MAX_VALUE)
                    .addComponent(customFrame, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(0, 0, Short.MAX_VALUE)))
        );

        PacketPane.addTab("Custom", customPane);

        builderFrame.setBorder(new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.LOWERED));

        builderPlaceholder.setText("Accept Args and Data and Etc");

        javax.swing.GroupLayout builderFrameLayout = new javax.swing.GroupLayout(builderFrame);
        builderFrame.setLayout(builderFrameLayout);
        builderFrameLayout.setHorizontalGroup(
            builderFrameLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(builderFrameLayout.createSequentialGroup()
                .addGap(66, 66, 66)
                .addComponent(builderPlaceholder, javax.swing.GroupLayout.PREFERRED_SIZE, 181, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(77, Short.MAX_VALUE))
        );
        builderFrameLayout.setVerticalGroup(
            builderFrameLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(builderFrameLayout.createSequentialGroup()
                .addGap(77, 77, 77)
                .addComponent(builderPlaceholder)
                .addContainerGap(118, Short.MAX_VALUE))
        );

        javax.swing.GroupLayout builderPaneLayout = new javax.swing.GroupLayout(builderPane);
        builderPane.setLayout(builderPaneLayout);
        builderPaneLayout.setHorizontalGroup(
            builderPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(builderPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(builderFrame, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );
        builderPaneLayout.setVerticalGroup(
            builderPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(builderPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(builderFrame, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );

        PacketPane.addTab("Packet Builder", builderPane);

        logScroll.setBackground(new java.awt.Color(50, 50, 50));
        logScroll.setForeground(new java.awt.Color(200, 200, 200));
        logScroll.setToolTipText("");

        logArea.setEditable(false);
        logArea.setBackground(new java.awt.Color(50, 50, 50));
        logArea.setContentType("text/pl"); // NOI18N
        logArea.setForeground(new java.awt.Color(200, 200, 200));
        logScroll.setViewportView(logArea);

        javax.swing.GroupLayout logPaneLayout = new javax.swing.GroupLayout(logPane);
        logPane.setLayout(logPaneLayout);
        logPaneLayout.setHorizontalGroup(
            logPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(logPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(logScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 325, Short.MAX_VALUE)
                .addContainerGap())
        );
        logPaneLayout.setVerticalGroup(
            logPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(logPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(logScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 208, Short.MAX_VALUE)
                .addContainerGap())
        );

        InfoPane.addTab("Packets", logPane);

        chartScroll.setBackground(new java.awt.Color(50, 50, 50));
        chartScroll.setForeground(new java.awt.Color(200, 200, 200));
        chartScroll.setToolTipText("");

        chartTable.setBackground(new java.awt.Color(50, 50, 50));
        chartTable.setForeground(new java.awt.Color(200, 200, 200));
        chartTable.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {
                {},
                {},
                {},
                {}
            },
            new String [] {

            }
        ));
        chartScroll.setViewportView(chartTable);

        javax.swing.GroupLayout chartPaneLayout = new javax.swing.GroupLayout(chartPane);
        chartPane.setLayout(chartPaneLayout);
        chartPaneLayout.setHorizontalGroup(
            chartPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(chartPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(chartScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 325, Short.MAX_VALUE)
                .addContainerGap())
        );
        chartPaneLayout.setVerticalGroup(
            chartPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(chartPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(chartScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 217, Short.MAX_VALUE)
                .addContainerGap())
        );

        InfoPane.addTab("Chart", chartPane);

        monsterScroll.setBackground(new java.awt.Color(50, 50, 50));
        monsterScroll.setForeground(new java.awt.Color(200, 200, 200));
        monsterScroll.setToolTipText("");

        monsterTable.setBackground(new java.awt.Color(50, 50, 50));
        monsterTable.setForeground(new java.awt.Color(200, 200, 200));
        monsterTable.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {
                {},
                {},
                {},
                {}
            },
            new String [] {

            }
        ));
        monsterScroll.setViewportView(monsterTable);

        javax.swing.GroupLayout monsterPaneLayout = new javax.swing.GroupLayout(monsterPane);
        monsterPane.setLayout(monsterPaneLayout);
        monsterPaneLayout.setHorizontalGroup(
            monsterPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(monsterPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(monsterScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 325, Short.MAX_VALUE)
                .addContainerGap())
        );
        monsterPaneLayout.setVerticalGroup(
            monsterPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(monsterPaneLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(monsterScroll, javax.swing.GroupLayout.DEFAULT_SIZE, 217, Short.MAX_VALUE)
                .addContainerGap())
        );

        InfoPane.addTab("Monster", monsterPane);

        inventoryList.setModel(new javax.swing.AbstractListModel<String>() {
            String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
            public int getSize() { return strings.length; }
            public String getElementAt(int i) { return strings[i]; }
        });
        inventoryScroll.setViewportView(inventoryList);

最佳答案

我假设这一行会导致NullPointerException:

logoButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/AQWBot/Icons/icon.png"))); // NOI18N

我也遇到了这个问题，当我将整个路径传递给图像时，它对我有用，例如:(假设图像位于包 at.daselias.resources.icons)

logoButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/at/daselias/resources/icons/icon.png"))); // NOI18N

这个问题总是只发生在 jar 文件中，而不是在 IDE 中。

编辑:当然，仅仅解决我建议的行中的问题还不够，您必须在加载资源的所有行中执行此操作。

关于java - .setIcon() 导致 NullPointerException，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/55990088/

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java - Java 缺少无符号原始类型是 Java 平台的特征还是 Java 语言的特征？
有关于why Java doesn't support unsigned types的问题以及一些关于处理无符号类型的问题。我做了一些搜索，似乎 Scala 也不支持无符号数据类型。限制是Java和S
java - Java 7 的 Java 字节码可以在其他版本的 Java 中工作吗
我只是想知道在一个 java 版本中生成的字节码是否可以在其他 java 版本上运行最佳答案通常，字节码无需修改即可在较新版本的 Java 上运行。它不会在旧版本上运行，除非您使用特殊参数 (
java -cp 。 test.java 与 java test.java
我有一个关于在命令提示符下执行 java 程序的基本问题。在某些机器上我们需要指定 -cp 。 (类路径)同时执行java程序 (test为java文件名与.class文件存在于同一目录下) jav
java - 使用 Java (Java EE/Java SE) 的数据库应用程序设计模式
我已经阅读 StackOverflow 有一段时间了，现在我才鼓起勇气提出问题。我今年 20 岁，目前在我的家乡(罗马尼亚克卢日-纳波卡)就读 IT 大学。足以介绍:D。基本上，我有一家提供簿记应用
java - Java 中的解析可在 Java 中访问
我有 public JSONObject parseXML(String xml) { JSONObject jsonObject = XML.toJSONObject(xml); r
java - Java 中的解释性语言以及对 Java 方法的调用
我已经在 Java 中实现了带有动态类型的简单解释语言。不幸的是我遇到了以下问题。测试时如下代码: def main() { def ks = Map[[1, 2]].keySet()
java - java 序数 - Java I 类
一直提示输入 1 到 10 的数字 - 结果应将 st、rd、th 和 nd 添加到数字中。编写一个程序，提示用户输入 1 到 10 之间的任意整数，然后以序数形式显示该整数并附加后缀。 public
java - 如何从 Java 执行 Java？
我有这个 DownloadFile.java 并按预期下载该文件: import java.io.*; import java.net.URL; public class DownloadFile {
java - 延迟不适用于 java gui(java)
我想在 GUI 上添加延迟。我放置了 2 个 for 循环，然后重新绘制了一个标签，但这 2 个 for 循环一个接一个地执行，并且标签被重新绘制到最后一个。我能做什么？ for(int i=0;
java - Java 类中的硬编码 Java 列表
我正在对对象 Student 的列表项进行一些测试，但是我更喜欢在 java 类对象中创建硬编码列表，然后从那里提取数据，而不是连接到数据库并在结果集中选择记录。然而，自从我这样做以来已经很长时间了，
java - java 幕后对象创建(java 对象实例化)
我知道对象创建分为三个部分: 声明实例化初始化 classA{} classB extends classA{} classA obj = new classB(1,1); 实例化它必须使用
java - 车辆跟踪系统[java/Java EE]
我有兴趣使用 GPRS 构建车辆跟踪系统。但是，我有一些问题要问以前做过此操作的人: GPRS 是最好的技术吗？人们意识到任何问题吗？我计划使用 Java/Java EE - 有更好的技术吗？如果
java - 逆数组(Java)//逆数组(Java)
我可以通过递归方法反转数组，例如:数组={1,2,3,4,5} 数组结果={5,4,3,2,1}但我的结果是相同的数组，我不知道为什么，请帮助我。 public class Recursion { p
java - Java/Java EE 的构建和集成环境
有这样的标准方式吗？包括 Java源代码-测试代码- Ant 或 Maven联合单元持续集成(可能是巡航控制)ClearCase 版本控制工具部署到应用服务器最后我希望有一个自动构建和集成环境。
java - 我将如何从 java 程序打印文本？ ( java )
我什至不知道这是否可能，我非常怀疑它是否可能，但如果可以，您能告诉我怎么做吗？我只是想知道如何从打印机打印一些文本。有什么想法吗？最佳答案这里有更简单的事情。 import javax.swin

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java - .setIcon() 导致 NullPointerException