Java Swing Tutorial - Java Swing JTextArea

A JTextArea can handle multiline plain text.

A JTextArea does not provide scrolling by itself, we need to put JTextField to a JScrollPane to have scrolling capability.

We can set the number of rows and columns for a JTextArea to set its preferred size.

The following table lists the constructors of the JTextArea Class.

ID	Constructor/Description
1	JTextArea() Creates a JTextArea with a default model, initial string as null, and rows/columns as zero.
2	JTextArea(Document doc) Creates a JTextArea with the specified doc as its model. Its initial string is set to null, and rows/columns to zero.
3	JTextArea(Document doc, String text, int rows, int columns) Creates a JTextArea with all its properties (model, initial text, rows, and column) as specified in its arguments.
4	JTextArea(int rows, int columns) Creates a JTextArea with a default model, initial string as null, and the specified rows/columns.
5	JTextArea(String text) Creates a JTextArea with the specified initial text. A default model is set and rows/columns are set to zero.
6	JTextArea(String text, int rows, int columns) Creates a JTextArea with the specified text, rows, and columns. A default model is used.

The following code shows how to create JTextArea using different initial values.

To Create a blank JTextArea

JTextArea emptyTextArea  = new JTextArea();

To create a JTextArea with 10 rows and 50 columns

JTextArea commentsTextArea  = new JTextArea(10, 50);

To Create a JTextArea with 10 rows and 50 columns with an initial text of "Enter resume here"

JTextArea resumeTextArea = new JTextArea("Enter resume here", 10, 50);

To add the scrolling capability to a JTextArea, we add it to a JScrollPane.

The following code shows how to make a JTextArea scrollable

JTextArea  resumeTextArea = new JTextArea("Enter resume  here", 10,   50);
JScrollPane sp  = new JScrollPane(resumeTextArea);
Container contentPane = myFrame.getContentPane();

The following table lists some of the commonly used methods of a JTextArea.

Most of the time, we will use its setText(), getText(), and append() methods.

ID	Method/Description
1	void append(String text) Appends the specified text to the end of the JTextArea.
2	int getLineCount() Returns the number of lines in the JTextArea.
3	int getLineStartOffset(int line) throws BadLocationException Returns the start offset for a specified line number.
4	int getLineEndOffset(int line) throws BadLocationException Returns the end offset for a specified line number.
5	int getLineOfOffset(int offset) throws BadLocationException Returns the line number in which the specified offset occurs.
6	boolean getLineWrap() Returns true if line wrapping has been set. Otherwise, it returns false.
7	int getTabSize() Returns the number of characters used for a tab. By default, it returns 8.
8	boolean getWrapStyleWord() Returns true if word wrapping has been set to true. Otherwise, it returns false.
9	void insert(String text, int offset) Inserts the specified text at the specified offset.
10	void replaceRange(String text, int start, int end) Replaces the text between the start and end positions with the specified text.
11	void setLineWrap(boolean wrap) Sets the line-wrapping policy for the JTextArea.
12	void setTabSize(int size) Sets the number of characters that a tab will expand to the specified size.
13	void setWrapStyleWord(boolean word) Sets the word-wrapping style when line wrapping is set to true.

By default, the line wrapping is set to false. The line wrapping is set using the setLineWrap(boolean lineWrap) method.