- java.lang.Object
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- java.awt.Component
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- java.awt.TextComponent
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- java.awt.TextField
 
 
 
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- All Implemented Interfaces:
- ImageObserver,- MenuContainer,- Serializable,- Accessible
 
 public class TextField extends TextComponent ATextFieldobject is a text component that allows for the editing of a single line of text.For example, the following image depicts a frame with four text fields of varying widths. Two of these text fields display the predefined text "Hello".  Here is the code that produces these four text fields: TextField tf1, tf2, tf3, tf4; // a blank text field tf1 = new TextField(); // blank field of 20 columns tf2 = new TextField("", 20); // predefined text displayed tf3 = new TextField("Hello!"); // predefined text in 30 columns tf4 = new TextField("Hello", 30);
 Every time the user types a key in the text field, one or more key events are sent to the text field. A KeyEventmay be one of three types: keyPressed, keyReleased, or keyTyped. The properties of a key event indicate which of these types it is, as well as additional information about the event, such as what modifiers are applied to the key event and the time at which the event occurred.The key event is passed to every KeyListenerorKeyAdapterobject which registered to receive such events using the component'saddKeyListenermethod. (KeyAdapterobjects implement theKeyListenerinterface.)It is also possible to fire an ActionEvent. If action events are enabled for the text field, they may be fired by pressing theReturnkey.The TextFieldclass'sprocessEventmethod examines the action event and passes it along toprocessActionEvent. The latter method redirects the event to anyActionListenerobjects that have registered to receive action events generated by this text field.
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Nested Class SummaryNested Classes Modifier and Type Class Description protected classTextField.AccessibleAWTTextFieldThis class implements accessibility support for theTextFieldclass.- 
Nested classes/interfaces declared in class java.awt.TextComponentTextComponent.AccessibleAWTTextComponent
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Nested classes/interfaces declared in class java.awt.ComponentComponent.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
 
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Field Summary- 
Fields declared in class java.awt.TextComponenttextListener
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Fields declared in class java.awt.ComponentaccessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT
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Fields declared in interface java.awt.image.ImageObserverABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH
 
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Constructor SummaryConstructors Constructor Description TextField()Constructs a new text field.TextField(int columns)Constructs a new empty text field with the specified number of columns.TextField(String text)Constructs a new text field initialized with the specified text.TextField(String text, int columns)Constructs a new text field initialized with the specified text to be displayed, and wide enough to hold the specified number of columns.
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Method SummaryAll Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description voidaddActionListener(ActionListener l)Adds the specified action listener to receive action events from this text field.voidaddNotify()Creates the TextField's peer.booleanechoCharIsSet()Indicates whether or not this text field has a character set for echoing.AccessibleContextgetAccessibleContext()Gets the AccessibleContext associated with this TextField.ActionListener[]getActionListeners()Returns an array of all the action listeners registered on this textfield.intgetColumns()Gets the number of columns in this text field.chargetEchoChar()Gets the character that is to be used for echoing.<T extends EventListener>
 T[]getListeners(Class<T> listenerType)Returns an array of all the objects currently registered asFooListeners upon thisTextField.DimensiongetMinimumSize()Gets the minimum dimensions for this text field.DimensiongetMinimumSize(int columns)Gets the minimum dimensions for a text field with the specified number of columns.DimensiongetPreferredSize()Gets the preferred size of this text field.DimensiongetPreferredSize(int columns)Gets the preferred size of this text field with the specified number of columns.DimensionminimumSize()Deprecated.As of JDK version 1.1, replaced bygetMinimumSize().DimensionminimumSize(int columns)Deprecated.As of JDK version 1.1, replaced bygetMinimumSize(int).protected StringparamString()Returns a string representing the state of thisTextField.DimensionpreferredSize()Deprecated.As of JDK version 1.1, replaced bygetPreferredSize().DimensionpreferredSize(int columns)Deprecated.As of JDK version 1.1, replaced bygetPreferredSize(int).protected voidprocessActionEvent(ActionEvent e)Processes action events occurring on this text field by dispatching them to any registeredActionListenerobjects.protected voidprocessEvent(AWTEvent e)Processes events on this text field.voidremoveActionListener(ActionListener l)Removes the specified action listener so that it no longer receives action events from this text field.voidsetColumns(int columns)Sets the number of columns in this text field.voidsetEchoChar(char c)Sets the echo character for this text field.voidsetEchoCharacter(char c)Deprecated.As of JDK version 1.1, replaced bysetEchoChar(char).voidsetText(String t)Sets the text that is presented by this text component to be the specified text.- 
Methods declared in class java.awt.TextComponentaddTextListener, enableInputMethods, getBackground, getCaretPosition, getSelectedText, getSelectionEnd, getSelectionStart, getText, getTextListeners, isEditable, processTextEvent, removeNotify, removeTextListener, select, selectAll, setBackground, setCaretPosition, setEditable, setSelectionEnd, setSelectionStart
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Methods declared in class java.awt.Componentaction, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, deliverEvent, disable, disableEvents, dispatchEvent, doLayout, enable, enable, enableEvents, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getAlignmentX, getAlignmentY, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentAt, getComponentAt, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeys, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMaximumSize, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, invalidate, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusCycleRoot, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, layout, list, list, list, list, list, locate, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paint, paintAll, postEvent, prepareImage, prepareImage, print, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, revalidate, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setMixingCutoutShape, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, validate
 
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Constructor Detail- 
TextFieldpublic TextField() throws HeadlessExceptionConstructs a new text field.- Throws:
- HeadlessException- if GraphicsEnvironment.isHeadless() returns true.
- See Also:
- GraphicsEnvironment.isHeadless()
 
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TextFieldpublic TextField(String text) throws HeadlessException Constructs a new text field initialized with the specified text.- Parameters:
- text- the text to be displayed. If- textis- null, the empty string- ""will be displayed. If- textcontains EOL and/or LF characters, then each will be replaced by space character.
- Throws:
- HeadlessException- if GraphicsEnvironment.isHeadless() returns true.
- See Also:
- GraphicsEnvironment.isHeadless()
 
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TextFieldpublic TextField(int columns) throws HeadlessExceptionConstructs a new empty text field with the specified number of columns. A column is an approximate average character width that is platform-dependent.- Parameters:
- columns- the number of columns. If- columnsis less than- 0,- columnsis set to- 0.
- Throws:
- HeadlessException- if GraphicsEnvironment.isHeadless() returns true.
- See Also:
- GraphicsEnvironment.isHeadless()
 
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TextFieldpublic TextField(String text, int columns) throws HeadlessException Constructs a new text field initialized with the specified text to be displayed, and wide enough to hold the specified number of columns. A column is an approximate average character width that is platform-dependent.- Parameters:
- text- the text to be displayed. If- textis- null, the empty string- ""will be displayed. If- textcontains EOL and/or LF characters, then each will be replaced by space character.
- columns- the number of columns. If- columnsis less than- 0,- columnsis set to- 0.
- Throws:
- HeadlessException- if GraphicsEnvironment.isHeadless() returns true.
- See Also:
- GraphicsEnvironment.isHeadless()
 
 
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Method Detail- 
addNotifypublic void addNotify() Creates the TextField's peer. The peer allows us to modify the appearance of the TextField without changing its functionality.- Overrides:
- addNotifyin class- TextComponent
- See Also:
- TextComponent.removeNotify()
 
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getEchoCharpublic char getEchoChar() Gets the character that is to be used for echoing.An echo character is useful for text fields where user input should not be echoed to the screen, as in the case of a text field for entering a password. If echoChar=0, user input is echoed to the screen unchanged.A Java platform implementation may support only a limited, non-empty set of echo characters. This function returns the echo character originally requested via setEchoChar(). The echo character actually used by the TextField implementation might be different. - Returns:
- the echo character for this text field.
- See Also:
- echoCharIsSet(),- setEchoChar(char)
 
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setEchoCharpublic void setEchoChar(char c) Sets the echo character for this text field.An echo character is useful for text fields where user input should not be echoed to the screen, as in the case of a text field for entering a password. Setting echoChar=0allows user input to be echoed to the screen again.A Java platform implementation may support only a limited, non-empty set of echo characters. Attempts to set an unsupported echo character will cause the default echo character to be used instead. Subsequent calls to getEchoChar() will return the echo character originally requested. This might or might not be identical to the echo character actually used by the TextField implementation. - Parameters:
- c- the echo character for this text field.
- Since:
- 1.1
- See Also:
- echoCharIsSet(),- getEchoChar()
 
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setEchoCharacter@Deprecated public void setEchoCharacter(char c) Deprecated.As of JDK version 1.1, replaced bysetEchoChar(char).Sets the character to be echoed when protected input is displayed.- Parameters:
- c- the echo character for this text field
 
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setTextpublic void setText(String t) Sets the text that is presented by this text component to be the specified text.- Overrides:
- setTextin class- TextComponent
- Parameters:
- t- the new text. If- tis- null, the empty string- ""will be displayed. If- tcontains EOL and/or LF characters, then each will be replaced by space character.
- See Also:
- TextComponent.getText()
 
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echoCharIsSetpublic boolean echoCharIsSet() Indicates whether or not this text field has a character set for echoing.An echo character is useful for text fields where user input should not be echoed to the screen, as in the case of a text field for entering a password. - Returns:
- trueif this text field has a character set for echoing;- falseotherwise.
- See Also:
- setEchoChar(char),- getEchoChar()
 
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getColumnspublic int getColumns() Gets the number of columns in this text field. A column is an approximate average character width that is platform-dependent.- Returns:
- the number of columns.
- Since:
- 1.1
- See Also:
- setColumns(int)
 
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setColumnspublic void setColumns(int columns) Sets the number of columns in this text field. A column is an approximate average character width that is platform-dependent.- Parameters:
- columns- the number of columns.
- Throws:
- IllegalArgumentException- if the value supplied for- columnsis less than- 0.
- Since:
- 1.1
- See Also:
- getColumns()
 
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getPreferredSizepublic Dimension getPreferredSize(int columns) Gets the preferred size of this text field with the specified number of columns.- Parameters:
- columns- the number of columns in this text field.
- Returns:
- the preferred dimensions for displaying this text field.
- Since:
- 1.1
 
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preferredSize@Deprecated public Dimension preferredSize(int columns) Deprecated.As of JDK version 1.1, replaced bygetPreferredSize(int).Returns the preferred size for this text field with the specified number of columns.- Parameters:
- columns- the number of columns
- Returns:
- the preferred size for the text field
 
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getPreferredSizepublic Dimension getPreferredSize() Gets the preferred size of this text field.- Overrides:
- getPreferredSizein class- Component
- Returns:
- the preferred dimensions for displaying this text field.
- Since:
- 1.1
- See Also:
- Component.getMinimumSize(),- LayoutManager
 
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preferredSize@Deprecated public Dimension preferredSize() Deprecated.As of JDK version 1.1, replaced bygetPreferredSize().Description copied from class:ComponentReturns the component's preferred size.- Overrides:
- preferredSizein class- Component
- Returns:
- the component's preferred size
 
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getMinimumSizepublic Dimension getMinimumSize(int columns) Gets the minimum dimensions for a text field with the specified number of columns.- Parameters:
- columns- the number of columns in this text field.
- Returns:
- the minimum size for this text field
- Since:
- 1.1
 
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minimumSize@Deprecated public Dimension minimumSize(int columns) Deprecated.As of JDK version 1.1, replaced bygetMinimumSize(int).Returns the minimum dimensions for a text field with the specified number of columns.- Parameters:
- columns- the number of columns
- Returns:
- the minimum size for this text field
 
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getMinimumSizepublic Dimension getMinimumSize() Gets the minimum dimensions for this text field.- Overrides:
- getMinimumSizein class- Component
- Returns:
- the minimum dimensions for displaying this text field.
- Since:
- 1.1
- See Also:
- Component.getPreferredSize(),- LayoutManager
 
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minimumSize@Deprecated public Dimension minimumSize() Deprecated.As of JDK version 1.1, replaced bygetMinimumSize().Description copied from class:ComponentReturns the minimum size of this component.- Overrides:
- minimumSizein class- Component
- Returns:
- the minimum size of this component
 
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addActionListenerpublic void addActionListener(ActionListener l) Adds the specified action listener to receive action events from this text field. If l is null, no exception is thrown and no action is performed.Refer to AWT Threading Issues for details on AWT's threading model. - Parameters:
- l- the action listener.
- Since:
- 1.1
- See Also:
- removeActionListener(java.awt.event.ActionListener),- getActionListeners(),- ActionListener
 
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removeActionListenerpublic void removeActionListener(ActionListener l) Removes the specified action listener so that it no longer receives action events from this text field. If l is null, no exception is thrown and no action is performed.Refer to AWT Threading Issues for details on AWT's threading model. - Parameters:
- l- the action listener.
- Since:
- 1.1
- See Also:
- addActionListener(java.awt.event.ActionListener),- getActionListeners(),- ActionListener
 
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getActionListenerspublic ActionListener[] getActionListeners() Returns an array of all the action listeners registered on this textfield.- Returns:
- all of this textfield's ActionListeners or an empty array if no action listeners are currently registered
- Since:
- 1.4
- See Also:
- addActionListener(java.awt.event.ActionListener),- removeActionListener(java.awt.event.ActionListener),- ActionListener
 
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getListenerspublic <T extends EventListener> T[] getListeners(Class<T> listenerType) Returns an array of all the objects currently registered asFooListeners upon thisTextField.FooListeners are registered using theaddFooListenermethod.You can specify the listenerTypeargument with a class literal, such asFooListener.class. For example, you can query aTextField tfor its action listeners with the following code:ActionListener[] als = (ActionListener[])(t.getListeners(ActionListener.class)); If no such listeners exist, this method returns an empty array.- Overrides:
- getListenersin class- TextComponent
- Type Parameters:
- T- the type of the listeners
- Parameters:
- listenerType- the type of listeners requested; this parameter should specify an interface that descends from- java.util.EventListener
- Returns:
- an array of all objects registered as
          FooListeners on this textfield, or an empty array if no such listeners have been added
- Throws:
- ClassCastException- if- listenerTypedoesn't specify a class or interface that implements- java.util.EventListener
- Since:
- 1.3
- See Also:
- getActionListeners()
 
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processEventprotected void processEvent(AWTEvent e) Processes events on this text field. If the event is an instance ofActionEvent, it invokes theprocessActionEventmethod. Otherwise, it invokesprocessEventon the superclass.Note that if the event parameter is nullthe behavior is unspecified and may result in an exception.- Overrides:
- processEventin class- TextComponent
- Parameters:
- e- the event
- Since:
- 1.1
- See Also:
- ActionEvent,- processActionEvent(java.awt.event.ActionEvent)
 
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processActionEventprotected void processActionEvent(ActionEvent e) Processes action events occurring on this text field by dispatching them to any registeredActionListenerobjects.This method is not called unless action events are enabled for this component. Action events are enabled when one of the following occurs: - An ActionListenerobject is registered viaaddActionListener.
- Action events are enabled via enableEvents.
 Note that if the event parameter is nullthe behavior is unspecified and may result in an exception.- Parameters:
- e- the action event
- Since:
- 1.1
- See Also:
- ActionListener,- addActionListener(java.awt.event.ActionListener),- Component.enableEvents(long)
 
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paramStringprotected String paramString() Returns a string representing the state of thisTextField. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not benull.- Overrides:
- paramStringin class- TextComponent
- Returns:
- the parameter string of this text field
 
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getAccessibleContextpublic AccessibleContext getAccessibleContext() Gets the AccessibleContext associated with this TextField. For text fields, the AccessibleContext takes the form of an AccessibleAWTTextField. A new AccessibleAWTTextField instance is created if necessary.- Specified by:
- getAccessibleContextin interface- Accessible
- Overrides:
- getAccessibleContextin class- TextComponent
- Returns:
- an AccessibleAWTTextField that serves as the AccessibleContext of this TextField
- Since:
- 1.3
 
 
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