Class Work: 1- Create a text file and Read in Java 2- Read a url and show in jav
ID: 3723465 • Letter: C
Question
Class Work: 1- Create a text file and Read in Java 2- Read a url and show in java 3- Read With JSoup and Show in java 4- Read with Jswing to prompt for open file. Show file content in Jpane Java swing example import javax.swing.*; public class InputDemo public static void main(String args[]) String stri JOptionPane.showInputDialog("Enter First Number"); String str2 JOptionPane.showinputDialog("Enter Second Number"); // input dialog returns always a string double fn Double.parseDouble(str1); double sn Double.parseDouble(str2); JOptionPane.showMessageDialog( null, "The Product is " + fn*sn, "Product JOptionPaneExplanation / Answer
Below I Have written codes and snippets for all the problem given
Hope this Helps ....Thank you. :)
1.create a text file and read in java
-->below function line can be used to read text file in java
//please change the path
-->below function line can be used to create text file in java
//new file is created in the directory of where your java file is saved
note:dont forget to import java.io.*;
2.Read URL and show in java
import java.net.*;
import java.io.*;
public class UrlReader
{
public static void main(String[] args) throws Exception
{
String urlString = "http://localhost:8080/";
// create the url
URL url = new URL(urlString);
// open the url stream, wrap it an a few "readers"
BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()));
// write the output to stdout
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
// close our reader
reader.close();
}
}
//note: write your url in place of localhost
3.Read with JSoup and show it in java
//below code is useful in list links from URL
package org.jsoup.examples;
import org.jsoup.Jsoup;
import org.jsoup.helper.Validate;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import java.io.IOException;
/**
* Example program to list links from a URL.
*/
public class ListLinks {
public static void main(String[] args) throws IOException {
Validate.isTrue(args.length == 1, "usage: supply url to fetch");
String url = args[0];
print("Fetching %s...", url);
Document doc = Jsoup.connect(url).get();
Elements links = doc.select("a[href]");
Elements media = doc.select("[src]");
Elements imports = doc.select("link[href]");
print(" Media: (%d)", media.size());
for (Element src : media) {
if (src.tagName().equals("img"))
print(" * %s: <%s> %sx%s (%s)",
src.tagName(), src.attr("abs:src"), src.attr("width"), src.attr("height"),
trim(src.attr("alt"), 20));
else
print(" * %s: <%s>", src.tagName(), src.attr("abs:src"));
}
print(" Imports: (%d)", imports.size());
for (Element link : imports) {
print(" * %s <%s> (%s)", link.tagName(),link.attr("abs:href"), link.attr("rel"));
}
print(" Links: (%d)", links.size());
for (Element link : links) {
print(" * a: <%s> (%s)", link.attr("abs:href"), trim(link.text(), 35));
}
}
private static void print(String msg, Object... args) {
System.out.println(String.format(msg, args));
}
private static String trim(String s, int width) {
if (s.length() > width)
return s.substring(0, width-1) + ".";
else
return s;
}
}
4.Read with JSwing to open for a new file and show it in JPanel
//below code prompts to select a file in file chooser and it appears in a jpanel
import java.awt.*;
import java.io.*;
import javax.swing.*;
import javax.swing.filechooser.FileFilter;
public class FileChooserExample {
public static void main(String[] args) {
new FileChooserExample();
}
public FileChooserExample() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JButton open;
private JTextArea textArea;
private JFileChooser chooser;
public TestPane() {
setLayout(new BorderLayout());
open = new JButton("Open");
textArea = new JTextArea(20, 40);
add(new JScrollPane(textArea));
add(open, BorderLayout.SOUTH);
open.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (chooser == null) {
chooser = new JFileChooser();
chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
chooser.setAcceptAllFileFilterUsed(false);
chooser.addChoosableFileFilter(new FileFilter() {
@Override
public boolean accept(File f) {
return f.isDirectory() || f.getName().toLowerCase().endsWith(".txt");
}
@Override
public String getDescription() {
return "Text Files (*.txt)";
}
});
}
switch (chooser.showOpenDialog(TestPane.this)) {
case JFileChooser.APPROVE_OPTION:
try (BufferedReader br = new BufferedReader(new FileReader(chooser.getSelectedFile()))) {
textArea.setText(null);
String text = null;
while ((text = br.readLine()) != null) {
textArea.append(text);
textArea.append(" ");
}
textArea.setCaretPosition(0);
} catch (IOException exp) {
exp.printStackTrace();
JOptionPane.showMessageDialog(TestPane.this, "Failed to read file", "Error", JOptionPane.ERROR_MESSAGE);
}
break;
}
}
});
}
}
}