Jni Font Error in Swing application - swing

Question

I get this Random Jni error, sometimes the codes works, sometimes it doesn't
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GraphicsEnvironment;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;
import javax.swing.text.BadLocationException;
import javax.swing.text.MutableAttributeSet;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyledDocument;
public class Fonts {
public static void main(String[] args) {
Fonts fs = new Fonts();
try {
fs.initialize();
} catch (Exception e) {
e.printStackTrace();
}
fs.frm.setVisible(true);
}
private String[] fnt;
private JFrame frm;
private JScrollPane jsp;
private JTextPane jta;
private int width = 450;
private int height = 300;
private GraphicsEnvironment ge = GraphicsEnvironment
.getLocalGraphicsEnvironment();
private Font[] fnts;
private StyledDocument doc;
private MutableAttributeSet mas;
// private String[] fams;
private int cp = 0;
public Fonts() {
}
public void dis(String s) {
try {
doc.insertString(cp, s, mas);
doc.insertString(cp, "\n", mas);
} catch (Exception e) {
e.printStackTrace();
}
}
public void initialize() throws BadLocationException {
frm = new JFrame("awesome");
frm.setMinimumSize(new Dimension(width, height));
frm.setBounds(100, 100, width, height);
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frm.getContentPane().setLayout(new BorderLayout());
fnts = ge.getAllFonts();
jta = new JTextPane();
doc = jta.getStyledDocument();
jsp = new JScrollPane(jta);
frm.getContentPane().add(jsp, BorderLayout.CENTER);
frm.pack();
fnt = ge.getAvailableFontFamilyNames();
mas = jta.getInputAttributes();
for (int i = 0; i < fnt.length; i++) {
StyleConstants.setBold(mas, false);
StyleConstants.setItalic(mas, false);
StyleConstants.setFontFamily(mas, fnt[i]);
StyleConstants.setFontSize(mas, 16);
dis(fnt[i]);
StyleConstants.setBold(mas, true);
dis(fnt[i] + " Bold");
StyleConstants.setItalic(mas, true);
dis(fnt[i] + " Bold & Italic");
StyleConstants.setBold(mas, false);
dis(fnt[i] + " Italic");
}
}
}
And here is the error I get.
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0xb3fdad10, pid=20482, tid=3066784624
#
# JRE version: 6.0_26-b03
# Java VM: Java HotSpot(TM) Client VM (20.1-b02 mixed mode, sharing linux-x86 )
# Problematic frame:
# C [libfontmanager.so+0x2ed10] float+0x40
#
# An error report file with more information is saved as:
# /home/alex/repos/java-alex.fonts/bin/hs_err_pid20482.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#
Aborted

Answer 1

added importans / standard Swing rulles
changed main method
moved all methods for JFrame from the toop to the end of methods,
set PrefferedSize to the JScrollPane
then for example
import java.awt.*;
import javax.swing.*;
import javax.swing.text.*;
public class Fonts {
private String[] fnt;
private JFrame frm;
private JScrollPane jsp;
private JTextPane jta;
private int width = 450;
private int height = 300;
private GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
private Font[] fnts;
private StyledDocument doc;
private MutableAttributeSet mas;
// private String[] fams;
private int cp = 0;
public Fonts() {
jta = new JTextPane();
doc = jta.getStyledDocument();
jsp = new JScrollPane(jta);
jsp.setPreferredSize(new Dimension(height, width));
fnt = ge.getAvailableFontFamilyNames();
mas = jta.getInputAttributes();
for (int i = 0; i < fnt.length; i++) {
StyleConstants.setBold(mas, false);
StyleConstants.setItalic(mas, false);
StyleConstants.setFontFamily(mas, fnt[i]);
StyleConstants.setFontSize(mas, 16);
dis(fnt[i]);
StyleConstants.setBold(mas, true);
dis(fnt[i] + " Bold");
StyleConstants.setItalic(mas, true);
dis(fnt[i] + " Bold & Italic");
StyleConstants.setBold(mas, false);
dis(fnt[i] + " Italic");
}
frm = new JFrame("awesome");
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frm.setLayout(new BorderLayout());
frm.add(jsp, BorderLayout.CENTER);
frm.setLocation(100, 100);
frm.pack();
frm.setVisible(true);
}
private void dis(String s) {
try {
doc.insertString(cp, s, mas);
doc.insertString(cp, "\n", mas);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
Fonts fs = new Fonts();
}
});
}
}
you have to change logics for adding Font to the JTextPane, there are wrong order from Z - > A (just my helicopter view)
EDIT: and changed access/visibily (# by attn trashgod)
from
public void dis(String s) {...
to
private void dis(String s) {...