Security, SocketPermission and applets

Question

Hi, Im trying to read an url from an applet but I dont know how to set the permissions from the applet.
here is my code:
import java.applet.*;
import java.net.*;
import java.io.*;
import java.awt.*;
public class TestApplet extends Applet{
private String line;
public void init () {
try {
URL url = new URL(
"http://www.yahoo.com");
BufferedReader in = new BufferedReader(
new InputStreamReader(url.openStream()));
line = in.readLine();
in.close();
}catch (Exception e){
e.printStackTrace();
public void paint (Graphics g) {
g.drawString (line, 20, 40);
And the problems are here:
java.security.AccessControlException: access denied (java.net.SocketPermission w
ww.yahoo.com resolve)
at java.security.AccessControlContext.checkPermission(AccessControlConte
xt.java:270)
at java.security.AccessController.checkPermission(AccessController.java:
401)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:542)
at java.lang.SecurityManager.checkConnect(SecurityManager.java:1042)
at java.net.InetAddress.getAllByName0(InetAddress.java:937)
at java.net.InetAddress.getAllByName0(InetAddress.java:918)
at java.net.InetAddress.getAllByName(InetAddress.java:912)
at java.net.InetAddress.getByName(InetAddress.java:832)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:293)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:264)
at sun.net.www.http.HttpClient.New(HttpClient.java:336)
at sun.net.www.http.HttpClient.New(HttpClient.java:317)
at sun.net.www.http.HttpClient.New(HttpClient.java:312)
Does anybosy knows how can i fix this program so it can work?
Thank you

Answer 1

In order to access anything in client machine u have sign ur applications.
Signing JAR Files with a Test Certificate
Here are the steps needed to sign a JAR file with a test certificate:
1. Make sure that you have a JDK 1.2 or JDK 1.3 keytool and jarsigner in your path (located in the J2SE SDK bin directory).
2. Create a new key in a new keystore as follows:
keytool -genkey -keystore myKeystore -alias myself
You will get prompted for a information about the new key, such as password, name, etc. This will create the myKeystore file on disk.
3. Then, create a self-signed test certificate as follows:
keytool -selfcert -alias myself -keystore myKeystore
This will prompt for the password. Generating the certificate takes a few minutes.
4. Check to make sure that everything is ok. To list the contents of the keystore, use the command:
keytool -list -keystore myKeystore
It should list something like:
Keystore type: jks
Keystore provider: SUN
Your keystore contains 1 entry:
myself, Tue Jan 23 19:29:32 PST 2001, keyEntry,
Certificate fingerprint (MD5):
C2:E9:BF:F9:D3:DF:4C:8F:3C:5F:22:9E:AF:0B:42:9D
5.Finally, sign the JAR file with the test certificate as follows:
jarsigner -keystore myKeystore test.jar myself
6. Repeat this step on all of your JAR files.
Please note that a self-signed test certificate should only be used for internal testing, since it does not provide any guarantees about the identity of the user and therefore cannot be trusted. A trust-worthy certificate can be obtained from a certificate authority, such as VeriSign, and should be used when the application is put into production.
Regards
Edward.i