通过 GUI 输入的文本中的换行符答案

【问题标题】：Linebreak in text inputted through GUI通过 GUI 输入的文本中的换行符
【发布时间】：2014-05-23 13:08:00
【问题描述】：

我正在尝试构建一个程序，该程序通过 GUI 接收带有换行符的输入文本，将其拆分为行，然后拆分为空格，并为每个字符串执行“特殊”操作。问题是2：

我无法在输入字段中添加换行符；
我不知道如何将换行符添加到输出中。

我该怎么做？我的代码是：

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author michelegorini
 */
import java.util.Scanner;
public class HakkaTranslator extends javax.swing.JFrame {

    /**
     * Creates new form HakkaTranslator
     */
    public HakkaTranslator() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        inputField = new javax.swing.JTextField();
        translateButton = new javax.swing.JButton();
        pinyinField = new javax.swing.JLabel();
        hakkaCharField = new javax.swing.JLabel();
        mandCharField = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        translateButton.setText("Translate");
        translateButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                translateButtonActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(hakkaCharField, javax.swing.GroupLayout.PREFERRED_SIZE, 282, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(mandCharField, javax.swing.GroupLayout.PREFERRED_SIZE, 216, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                            .addComponent(translateButton, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(inputField, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 252, Short.MAX_VALUE))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(pinyinField, javax.swing.GroupLayout.PREFERRED_SIZE, 282, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(0, 0, Short.MAX_VALUE)))
                .addContainerGap())
        );

        layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {hakkaCharField, inputField, mandCharField, pinyinField});

        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(translateButton)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(pinyinField, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(inputField, javax.swing.GroupLayout.DEFAULT_SIZE, 165, Short.MAX_VALUE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(hakkaCharField, javax.swing.GroupLayout.PREFERRED_SIZE, 136, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(mandCharField))
                .addContainerGap(177, Short.MAX_VALUE))
        );

        layout.linkSize(javax.swing.SwingConstants.VERTICAL, new java.awt.Component[] {hakkaCharField, inputField, mandCharField, pinyinField});

        pack();
    }// </editor-fold>                        

    private void translateButtonActionPerformed(java.awt.event.ActionEvent evt) {                                                
        // TODO add your handling code here:
        Scanner kLFeed = new Scanner(inputField.getText()).useDelimiter("\n");
        Scanner kSp;
        do{
            kSp = new Scanner(kLFeed.next());
            while(kSp.hasNext()){
                translate(kSp.next());
            }
            translate("<br/>");
        } while(kLFeed.hasNext());
    }                                               

    private void translate(String word) {
        pinyinField.setText(pinyinField.getText() + word);
    }
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(HakkaTranslator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(HakkaTranslator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(HakkaTranslator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(HakkaTranslator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new HakkaTranslator().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JLabel hakkaCharField;
    private javax.swing.JTextField inputField;
    private javax.swing.JLabel mandCharField;
    private javax.swing.JLabel pinyinField;
    private javax.swing.JButton translateButton;
    // End of variables declaration                   

}

目前。

更新： 考虑到答案和 cmets，我得出：

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author michelegorini
 */
import java.util.Scanner;
public class HakkaTranslator extends javax.swing.JFrame {

    /**
     * Creates new form HakkaTranslator
     */
    public HakkaTranslator() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
    private void initComponents() {

        inputField = new javax.swing.JTextArea();
        translateButton = new javax.swing.JButton();
        pinyinField = new javax.swing.JLabel();
        hakkaCharField = new javax.swing.JLabel();
        mandCharField = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        translateButton.setText("Translate");
        translateButton.addActionListener(new java.awt.event.ActionListener() {

            @Override
            public void actionPerformed(java.awt.event.ActionEvent e) {

                inpText = inputField.getText();
                String[] lines = inpText.split(System.lineSeparator());
                String[][] words = new String[lines.length][20];
                for(int i=0;i<lines.length;i++){
                    words[i] = lines[i].split(" ");
                }
                for(int i=0;i<lines.length;i++){
                    for(int j = 0;j<words[i].length;j++){
                        translate(words[i][j]);
                    }
                    translate(System.lineSeparator());
                }
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(hakkaCharField, javax.swing.GroupLayout.PREFERRED_SIZE, 282, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(mandCharField, javax.swing.GroupLayout.PREFERRED_SIZE, 216, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                            .addComponent(translateButton, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(inputField, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 252, Short.MAX_VALUE))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(pinyinField, javax.swing.GroupLayout.PREFERRED_SIZE, 282, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(0, 0, Short.MAX_VALUE)))
                .addContainerGap())
        );

        layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {hakkaCharField, inputField, mandCharField, pinyinField});

        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(translateButton)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(pinyinField, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(inputField, javax.swing.GroupLayout.DEFAULT_SIZE, 165, Short.MAX_VALUE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(hakkaCharField, javax.swing.GroupLayout.PREFERRED_SIZE, 136, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(mandCharField))
                .addContainerGap(177, Short.MAX_VALUE))
        );

        layout.linkSize(javax.swing.SwingConstants.VERTICAL, new java.awt.Component[] {hakkaCharField, inputField, mandCharField, pinyinField});

        pack();
    }// </editor-fold>//GEN-END:initComponents

    private void translate(String word) {
        pinyinField.setText(pinyinField.getText() + word + " ");
    }
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(HakkaTranslator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(HakkaTranslator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(HakkaTranslator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(HakkaTranslator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new HakkaTranslator().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JLabel hakkaCharField;
    private javax.swing.JTextArea inputField;
    private javax.swing.JLabel mandCharField;
    private javax.swing.JLabel pinyinField;
    private javax.swing.JButton translateButton;
    // End of variables declaration//GEN-END:variables
    String inpText;
}

一个问题仍然存在：即使使用System.lineSeparator()，输出中的换行符也不会出现。我该如何解决？以及如何避免每次都出现javax.swing？

【问题讨论】：

你为什么使用文本字段而不是文本区域？
嗯……我真的不知道有什么区别:)。代码大部分是由 NetBeams 自动生成的，我对 java GUI 的了解……嗯……可能比基本的还少:)。
据我所知，文本字段是单行文本。只有 TextArea 可以有多行。
好的，我尝试将每个TextField 更改为TextArea，但返回键仍然没有任何作用:(。
输入一个很长的字符串会导致……出现在输出中。

标签： java swing input graphics interface

【解决方案1】：

这是一个如何将文本区域的文本读取为字符串的示例。

public class GetterText extends JFrame {

    JTextArea ta = new JTextArea();
    String taText;

    GetterText() {

        JButton getText = new JButton("GetText");
        getText.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                taText = ta.getText();
                System.out.println(taText);
            }
        });

        getContentPane().add(getText, BorderLayout.LINE_START);
        getContentPane().add(new JScrollPane(ta));
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        pack();
        setVisible(true);
    }

    public static void main(String[] args) {

        new GetterText();
    }
}

您可以使用taText.split(" ") 分割空格，使用taText.split("\\n") 分割行。

【讨论】：

嗯……cannot find symbol symbol class JFrame……也许是 javax.swing.JFrame？对于所有其他 GUI 类也是如此。
但是没有awt，我不能输入javax.awt.event.ActionListener，而且我知道没有其他方法可以在这里创建ActionListener，因为只需输入ActionListener就可以得到cannot find symbol，就像JFrame，那么……我该怎么办？
@MickG 只有一个JFrame - 你所说的那个。您的 GUI 构建器会编写完全限定的名称。我建议您编写自己的 GUI，而不是使用构建器。使用导入而不是在代码中编写完全限定名称。
@MickG 我说使用 Swing 组件而不是 AWT 组件。这些事件在 AWT 和 Swing（建立在 AWT 之上）之间共享。
@MickG 添加import javax.swing.JFrame;这一行。