By default, accessing an HTTPS URL using the URL class results in an exception if the server’s certificate chain cannot be validated has not previously been installed in the truststore. If you want to disable the validation of certificates for testing purposes, you need to override the default trust manager with one that trusts all certificates.

// Create a trust manager that does not validate certificate chains
TrustManager[] trustAllCerts = new TrustManager[]{
    new X509TrustManager() {
        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
            return null;
        }
        public void checkClientTrusted(
            java.security.cert.X509Certificate[] certs, String authType) {
        }
        public void checkServerTrusted(
            java.security.cert.X509Certificate[] certs, String authType) {
        }
    }
};

// Install the all-trusting trust manager
try {
    SSLContext sc = SSLContext.getInstance("SSL");
    sc.init(null, trustAllCerts, new java.security.SecureRandom());
    HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
} catch (Exception e) {
}

// Now you can access an https URL without having the certificate
// in the truststore
try {
    URL url = new URL("https://hostname/index.html");
} catch (MalformedURLException e) {
}

The system is out of resources.
Consult the following stack trace for details.
java.lang.OutOfMemoryError: Java heap space

It’s no different than OutOfMemoryError in other java applications. When you run javac in Sun JDK, it’s invoking com.sun.tools.javac.main.Main located in %JAVA_HOME%\lib\tools.jar.

If you are compiling with javac task in Apache Ant, set fork attribute to true, to run javac in a separate process with its own heap size settings. If fork is set to false, or not set (default is false), javac will run in the same process as Ant, which has a default maximum heap size of 64m.

<javac fork="true">
       srcdir="${basedir}/src"
       destdir="${basedir}/build/classes"
       classpath="${project.classpath}"
       memoryinitialsize="256m"
       memorymaximumsize="256m"&gt;
</javac>

Setting fork to true will also limit any memory leaks in javac implementation to its own child process, without affecting the parent Ant process.