Applet + Read File??????

Question

Hello security gurus:
Could somebody suggest an easy way to read a single xml file from originating on the same sever and directory where the applet resides? People say that an applet can access file from the working directory and all sub-directories this works fine on my system when
executed directly from the appletviewer or the browser but when I load my program and it's dependencies in a webserver such as tomcat or apache it chokes on applet security exceptions. If someone could help I could stop
beating my head on the desk where my workstation resides.
Thanks, Ian

Answer 1

Hi Bakrudeen,
I�m a newbie into Java Applets ( so, Java too ), I work with C and C++, but now I need to do somethings using Java. One it�s that I need to do a Applet that read a xml file that�s into my webserver, in the same direcotry that my .class files are. First, I did a java class that run stand alone, it read the file perfectly, after I did a class that extends the applet class, but it didn�t found. Reading your e-mail, I had some questions, than, can you explain better your ideas ? Because, I have the plugins in my machine ( not in the server, the server doesn�t have anything about java, only the Apache server, my webpages and applet classes ), but I can�t read the file ? Another question is: how can I do to see the exceptions messagens to try looking for my errors ?
See below the source code that I�m trying to use:
import javax.swing.*;
import java.awt.*;
import java.applet.*;
import java.net.*;
import java.io.*;
import org.w3c.dom.Document;
import org.w3c.dom.*;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
public class WS10Parser extends Applet {
public int finished;     // 0 - n�o encerrado
// 1 - encerrado
// 2 - erro
private JanelTexto janela;
public void init() {
janela = new JanelTexto();
public void paint(Graphics g) {
//          g.drawString("Welcome to Java!!", 50, 60 );
* Fun��o para leitura do arquivo XML
* Parametros:
* - Nome do arquivo XML a ser lido
* - Nome do Dispositivo a ser lido
* - Modo de leitura do arquivo
*     - 1 L� somente dados referentes ao dispositivo identificado pelo Nome
*     - 0     L� informa��es de todos os Devices no arquivo
//     public void ReadFile(String FileName, String DeviceName, int Mode) {
public void ReadFile(String FileName) {
finished = 0;
URL url;
try {
url = new URL(getCodeBase(), FileName);
janela.AddText("File name: " + url.toString());
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
Document doc = docBuilder.parse(url.openStream());
// normalize text representation
doc.getDocumentElement().normalize();
janela.AddText("Root element of the doc is " + doc.getDocumentElement().getNodeName());
NodeList listOfDevices = doc.getElementsByTagName("device");
int totalDevices = listOfDevices.getLength();
janela.AddText("Total no of devices : " + totalDevices);
for(int s=0; s<listOfDevices.getLength() ; s++){
Node firstDeviceNode = listOfDevices.item(s);
if(firstDeviceNode.getNodeType() == Node.ELEMENT_NODE){
Element firstDeviceElement = (Element)firstDeviceNode;
NodeList firstNameList = firstDeviceElement.getElementsByTagName("name");
Element firstNameElement = (Element)firstNameList.item(0);
NodeList textFNList = firstNameElement.getChildNodes();
janela.AddText("Device Name : " + ((Node)textFNList.item(0)).getNodeValue().trim());
NodeList lastNameList = firstDeviceElement.getElementsByTagName("timestamp");
Element lastNameElement = (Element)lastNameList.item(0);
NodeList textLNList = lastNameElement.getChildNodes();
janela.AddText("TimeStamp : " + ((Node)textLNList.item(0)).getNodeValue().trim());
NodeList listOfChannels = firstDeviceElement.getElementsByTagName("channel");
int totalChannels = listOfChannels.getLength();
janela.AddText("Total no of channels: " + totalChannels);
for(int cont = 0; cont < listOfChannels.getLength(); cont++) {
Node channelNode = listOfChannels.item(cont);
if(channelNode.getNodeType() == Node.ELEMENT_NODE) {
Element channelElement = (Element)channelNode;
NodeList tagList = channelElement.getElementsByTagName("tag");
Element tagElement = (Element)tagList.item(0);
NodeList textTagList = tagElement.getChildNodes();
janela.AddText("Tag: " + ((Node)textTagList.item(0)).getNodeValue().trim());
NodeList valueList = channelElement.getElementsByTagName("value");
Element valueElement = (Element)valueList.item(0);
NodeList textValueList = valueElement.getChildNodes();
janela.AddText("Value: " + ((Node)textValueList.item(0)).getNodeValue().trim());
}//end of if clause
}//end of for loop with s var
finished = 1;
}catch (SAXParseException err) {
janela.AddText("** Parsing error" + ", line " + err.getLineNumber() + ", uri " + err.getSystemId());
janela.AddText(" " + err.getMessage());
finished = 2;
}catch (SAXException e) {
Exception x = e.getException();
((x == null) ? e : x).printStackTrace();
finished = 3;
}catch (Throwable t) {
t.printStackTrace();
finished = 4;
private class JanelTexto extends JFrame {
private JTextArea ta;
public JanelTexto() {
super("Teste Applet Novus");
Box b = Box.createHorizontalBox();
ta = new JTextArea(20, 30);
b.add(new JScrollPane(ta));
Container c = getContentPane();
c.add(b);
setSize(425, 200);
show();
public void AddText(String Text) {
ta.append(Text + '\n');
Thanks