public class JTextField
extends JTextComponent implements SwingConstants

java.lang.Object
 Ｌ java.awt.Component
     Ｌ java.awt.Container
         Ｌ javax.swing.JComponent
             Ｌ javax.swing.text.JTextComponent
                 Ｌ javax.swing.JTextField

JTextFieldクラスのオブジェクトを作成

JTextField
public JTextField()

JTextField
public JTextField(int columns)

JTextField text1 = new JTextField();
JTextField text2 = new JTextField(10);

幅の設定

setColumns
public void setColumns(int columns)

JTextField text = new JTextField();
text.setColumns(10);

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;

class SSample1_1 extends JFrame{
  public static void main(String args[]){
    SSample1_1 frame = new SSample1_1("タイトル");
    frame.setVisible(true);
  }

  SSample1_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField();
    JTextField text2 = new JTextField(10);
    JTextField text3 = new JTextField();
    text3.setColumns(15);

    p.add(text1);
    p.add(text2);
    p.add(text3);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

コンストラクタで指定

JTextField
public JTextField(String text)

JTextField
public JTextField(String text, int columns)

JTextField text1 = new JTextField("初期値");
JTextField text2 = new JTextField("初期値", 10);

メソッドを使って設定する

setText
public void setText(String t)

JTextField text = new JTextField();
text.setText("文字列");

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;

class SSample2_1 extends JFrame{
  public static void main(String args[]){
    SSample2_1 frame = new SSample2_1("タイトル");
    frame.setVisible(true);
  }

  SSample2_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField("東京都");
    JTextField text2 = new JTextField("東京都", 10);
    JTextField text3 = new JTextField(15);
    text3.setText("住所を入力して下さい");

    p.add(text1);
    p.add(text2);
    p.add(text3);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

setForeground
public void setForeground(Color fg)

JTextField text = new JTextField(10);

text.setForeground(Color.RED);

setBackground
public void setBackground(Color bg)

JTextField text = new JTextField(10);

text.setBackground(Color.BLACK);

透明/非透明の切り替え

setOpaque
public void setOpaque(boolean isOpaque)

JTextField text = new JTextField(10);
text.setOpaque(false);

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.Color;

class SSample3_1 extends JFrame{
  public static void main(String args[]){
    SSample3_1 frame = new SSample3_1("タイトル");
    frame.setVisible(true);
  }

  SSample3_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField("東京都", 20);

    JTextField text2 = new JTextField("東京都", 20);
//    text2.setForeground(Color.WHITE);
    text2.setForeground(Color.BLUE);
//    text2.setBackground(Color.BLACK);
    text2.setBackground( new Color(176,255,176));

    JTextField text3 = new JTextField("大阪府", 20);
    text3.setOpaque(false);

    p.add(text1);
    p.add(text2);
    p.add(text3);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

setFont
public void setFont(Font font)

JTextField text = new JTextField(10);

text.setFont(new Font("ＭＳ ゴシック", Font.BOLD, 16));

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.Font;

class SSample4_1 extends JFrame{
  public static void main(String args[]){
    SSample4_1 frame = new SSample4_1("タイトル");
    frame.setVisible(true);
  }

  SSample4_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField("東京都千代田区");

    JTextField text2 = new JTextField("東京都千代田区");
    text2.setFont(new Font("ＭＳ ゴシック", Font.PLAIN, 8));

    JTextField text3 = new JTextField("東京都千代田区");
    text3.setFont(new Font("ＭＳ ゴシック", Font.PLAIN, 30));

    p.add(text1);
    p.add(text2);
    p.add(text3);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

setPreferredSize
public void setPreferredSize(Dimension preferredSize)

JTextField text = new JTextField();

text.setPreferredSize(new Dimension(200, 100));

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.Dimension;

class SSample5_1 extends JFrame{
  public static void main(String args[]){
    SSample5_1 frame = new SSample5_1("タイトル");
    frame.setVisible(true);
  }

  SSample5_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField("東京都千代田区神田");
    text1.setPreferredSize(new Dimension(200, 15));

    JTextField text2 = new JTextField("東京都千代田区神田");
    text2.setPreferredSize(new Dimension(200, 80));

    JTextField text3 = new JTextField("東京都千代田区神田");
    text3.setPreferredSize(new Dimension(100, 40));

    JTextField text4 = new JTextField("東京都千代田区神田");
    text4.setFont(new Font("ＭＳ ゴシック", Font.PLAIN, 30));
    text4.setPreferredSize(new Dimension(200, 20));

    p.add(text1);
    p.add(text2);
    p.add(text3);
    p.add(text4);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.Dimension;

class SSample5_2 extends JFrame{
  public static void main(String args[]){
    SSample5_2 frame = new SSample5_2("タイトル");
    frame.setVisible(true);
  }

  SSample5_2(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField();
    text1.setPreferredSize(new Dimension(200, 30));

    JTextField text2 = new JTextField(15);
    text2.setPreferredSize(new Dimension(50, 30));

    JTextField text3 = new JTextField(15);
    text3.setPreferredSize(new Dimension(200, 30));

    JTextField text4 = new JTextField(15);
    text4.setPreferredSize(new Dimension(200, 10));

    JTextField text5 = new JTextField(15);
    text5.setPreferredSize(new Dimension(200, 60));

    p.add(text1);
    p.add(text2);
    p.add(text3);
    p.add(text4);
    p.add(text5);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

余白の設定

setMargin
public void setMargin(Insets m)

JTextField text = new JTextField();

text.setMargin(new Insets(10, 10, 10, 10));

枠線の設定

setBorder
public void setBorder(Border border)

JTextField text = new JTextField();

LineBorder border = new LineBorder(Color.RED, 2, true);
text.setBorder(border);

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.LineBorder;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.Color;

class SSample6_1 extends JFrame{
  public static void main(String args[]){
    SSample6_1 frame = new SSample6_1("タイトル");
    frame.setVisible(true);
  }

  SSample6_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField("東京都千代田区神田");

    JTextField text2 = new JTextField("東京都千代田区神田");
    text2.setMargin(new Insets(20, 40, 20, 40));

    JTextField text3 = new JTextField("東京都千代田区神田");
    text3.setPreferredSize(new Dimension(250, 50));
    text3.setMargin(new Insets(20, 20, 20, 20));

    JTextField text4 = new JTextField(20);
    text4.setBorder(new LineBorder(Color.BLUE, 4, true));

    p.add(text1);
    p.add(text2);
    p.add(text3);
    p.add(text4);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

setHorizontalAlignment
public void setHorizontalAlignment(int alignment)

JTextField.LEFT       左詰
JTextField.CENTER     中央
JTextField.RIGHT      右詰
JTextField.LEADING    左詰
JTextField.TRAILING   右詰

JTextField text = new JTextField();

text.setHorizontalAlignment(JTextField.CENTER);

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;

class SSample7_1 extends JFrame{
  public static void main(String args[]){
    SSample7_1 frame = new SSample7_1("タイトル");
    frame.setVisible(true);
  }

  SSample7_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField("東京都千代田区神田", 20);
    text1.setHorizontalAlignment(JTextField.LEFT);

    JTextField text2 = new JTextField("東京都千代田区神田", 20);
    text2.setHorizontalAlignment(JTextField.CENTER);

    JTextField text3 = new JTextField("東京都千代田区神田", 20);
    text3.setHorizontalAlignment(JTextField.RIGHT);

    p.add(text1);
    p.add(text2);
    p.add(text3);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

setCaretPosition
public void setCaretPosition(int position)

JTextField text = new JTextField("初期値");
text.setCaretPosition(1);

JTextField text = new JTextField("初期値");
text.setCaretPosition(text.getText().length());

キャレットの色の設定

setCaretColor
public void setCaretColor(Color c)

JTextField text = new JTextField("初期値");
text.setCaretColor(Color.RED);

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.Color;

class SSample8_1 extends JFrame{
  public static void main(String args[]){
    SSample8_1 frame = new SSample8_1("タイトル");
    frame.setVisible(true);
  }

  SSample8_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text = new JTextField("こんにちは", 20);
    text.setCaretPosition(text.getText().length());
    text.setCaretColor(Color.RED);

    p.add(text);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

getText
public String getText()

JTextField text = new JTextField("初期値");
String str = text.getText();

指定した位置の値を取得する

getText
public String getText(int offs, int len) throws BadLocationException

JTextField text = new JTextField("初期値");
try{
  String str = text.getText(0, 2);
}catch(BadLocationException e){
  System.out.println("Bad Location Error!");
}

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.JLabel;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

class SSample9_1 extends JFrame implements ActionListener{

  JTextField text1;
  JTextField text2;
  JLabel label;

  public static void main(String args[]){
    SSample9_1 frame = new SSample9_1("タイトル");
    frame.setVisible(true);
  }

  SSample9_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    text1 = new JTextField("住所1", 20);
    text2 = new JTextField("住所2", 20);
    JButton button = new JButton("取得");
    button.addActionListener(this);
    label = new JLabel();

    p.add(text1);
    p.add(text2);
    p.add(button);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
    contentPane.add(label, BorderLayout.SOUTH);
  }

  public void actionPerformed(ActionEvent e){
    label.setText(text1.getText() + text2.getText());
  }
}

getSelectedText
public String getSelectedText()

JTextField text = new JTextField("初期値");
String str = text.getSelectedText();

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.JLabel;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

class SSample10_1 extends JFrame implements ActionListener{

  JTextField text;
  JLabel label;

  public static void main(String args[]){
    SSample10_1 frame = new SSample10_1("タイトル");
    frame.setVisible(true);
  }

  SSample10_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    text = new JTextField("住所", 20);
    JButton button = new JButton("選択部分を取得");
    button.addActionListener(this);
    label = new JLabel();

    p.add(text);
    p.add(button);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
    contentPane.add(label, BorderLayout.SOUTH);
  }

  public void actionPerformed(ActionEvent e){
    label.setText(text.getSelectedText());
  }
}

select
public void select(int selectionStart, int selectionEnd)

JTextField text = new JTextField("初期値");
text.select(0, 1);

setSelectionStart
public void setSelectionStart(int selectionStart)

setSelectionEnd
public void setSelectionEnd(int selectionEnd)

JTextField text = new JTextField("初期値");
text.setSelectionStart(0);
text.setSelectionEnd(1);

全てを選択

selectAll
public void selectAll()

JTextField text = new JTextField("初期値");
text.selectAll();

フォーカスの設定

requestFocusInWindow
public boolean requestFocusInWindow()

JTextField text = new JTextField("初期値");
text.requestFocusInWindow();
text.selectAll();

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

class SSample11_1 extends JFrame implements ActionListener{

  JTextField text;

  public static void main(String args[]){
    SSample11_1 frame = new SSample11_1("タイトル");
    frame.setVisible(true);
  }

  SSample11_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    text = new JTextField("住所", 20);
    text.select(0, 1);
    JButton button = new JButton("全て選択");
    button.addActionListener(this);

    p.add(text);
    p.add(button);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }

  public void actionPerformed(ActionEvent e){
    text.requestFocusInWindow();
    text.selectAll();
  }
}

編集可能/不可の切り替え

setEditable
public void setEditable(boolean b)

JTextField text = new JTextField("初期値");
text.setEditable(false);

有効/無効の切り替え

setEnabled
public void setEnabled(boolean enabled)

JTextField text = new JTextField("初期値");
text.setEnabled(false);

無効時のテキストの色

setDisabledTextColor
public void setDisabledTextColor(Color c)

JTextField text = new JTextField("初期値");
text.setEnabled(false);
text.setDisabledTextColor(Color.BLACK);

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.Container;
import java.awt.BorderLayout;

class SSample12_1 extends JFrame{

  public static void main(String args[]){
    SSample12_1 frame = new SSample12_1("タイトル");
    frame.setVisible(true);
  }

  SSample12_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text1 = new JTextField("東京都港区赤坂", 20);
    JTextField text2 = new JTextField("東京都港区赤坂", 20);
    text2.setEditable(false);
    JTextField text3 = new JTextField("東京都港区赤坂", 20);
    text3.setEnabled(false);

    p.add(text1);
    p.add(text2);
    p.add(text3);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

copy
public void copy()

cut
public void cut()

paste
public void paste()

JTextField text = new JTextField("初期値");
texta.cut();
text.copy();
text.paste();

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

class SSample13_1 extends JFrame{

  JTextField text;

  public static void main(String args[]){
    SSample13_1 frame = new SSample13_1("タイトル");
    frame.setVisible(true);
  }

  SSample13_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    text = new JTextField("東京都港区赤坂", 25);

    JButton buttonCut = new JButton("CUT");
    buttonCut.addActionListener(
      new ActionListener(){
        public void actionPerformed(ActionEvent event){
          text.cut();
        }
      }
    );

    JButton buttonCopy = new JButton("COPY");
    buttonCopy.addActionListener(
      new ActionListener(){
        public void actionPerformed(ActionEvent event){
          text.copy();
        }
      }
    );

    JButton buttonPaste = new JButton("PASTE");
    buttonPaste.addActionListener(
      new ActionListener(){
        public void actionPerformed(ActionEvent event){
          text.paste();
        }
      }
    );

    p.add(text);
    p.add(buttonCut);
    p.add(buttonCopy);
    p.add(buttonPaste);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}

setToolTipText
public void setToolTipText(String text)

JTextField text = new JTextField("初期値");
text.setToolTipText("文字の入力");

サンプルプログラム

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.BorderLayout;

class SSample14_1 extends JFrame{
  public static void main(String args[]){
    SSample14_1 frame = new SSample14_1("タイトル");
    frame.setVisible(true);
  }

  SSample14_1(String title){
    setTitle(title);
    setBounds(100, 100, 300, 250);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel p = new JPanel();

    JTextField text = new JTextField("東京都港区赤坂", 25);
    text.setToolTipText("テキストを入力して下さい");

    p.add(text);

    Container contentPane = getContentPane();
    contentPane.add(p, BorderLayout.CENTER);
  }
}