Just a reminder that I got this error when I set the Java system property javax.net.ssl.trustStore to a non-existing file (typo). The full error message when running Maven was: [ERROR] java.lang.RuntimeException: Unexpected e...

This is the error message: Error 6 initializing SQL*Plus SP2-0667: Message... It might be that the ORACLE_HOME environment variable is not properly set or a missing sp1<lang>.msb (for example sp1us.msb ) file. But for my Ubuntu system, there was no such thing as sp1<lang>.msb , and it wasn't caused by a missing ORACLE_HOME . The error was resolved after I restored the shared library file libsqlplusic.so .

Tomcat 7.0 failed with a SEVERE error without printing a stack trace: Dec 30, 2011 1:21:09 PM org.apache.catalina.core.S... Now it's hard to figure out what's wrong without knowing where things went wrong. Why is Tomcat not logging anything? Tomcat logging is configured by class loader. Logging behaves differently depending on which class loader loaded the logger. You'll need to look at both $CATALINA_BASE/conf/logging.properties and WEB-INF/classes/logging.properties to figure out why the stack trace is not logged. In my case, the web app specific WEB-INF/classes/logging.properties overshadowed the system $CATALINA_BASE/conf/logging.properties and suppressed the stack trace.

#include <stdio.h> #include <stdlib.h> #incl... UNIXguide.net explains this option well: This socket option tells the kernel that even if this port is busy (in the TIME_WAIT state), go ahead and reuse it anyway. If it is busy, but with another state, you will still get an address already in use error. It is useful if your server has been shut down, and then restarted right away while sockets are still active on its port. You should be aware that if any unexpected data comes in, it may confuse your server, but while this is possible, it is not likely. It has been pointed out that "A socket is a 5 tuple (proto, local addr, local port, remote addr, remote port). SO_REUSEADDR just says that you...

This code snippet import java.util.*; public class UncheckedCast ... fails with a compilation error and a warning: $ javac -Xlint:unchecked UncheckedCast.java Unc... Because List<String> is not a reifiable type, the Java Runtime does not have enough information to verify the type or do the type casting. This is fixed by changing List<String> to List<?> (or to the raw type List ): public static void main(String[] args) { Ob...

Install APK with adb : $ platform-tools/adb install out/target/product/ge... Error message in logcat: D/PackageParser( 60): Scanning package: /data/ap... The error was created by android.content.pm.PackageParser , which compares the android:minSdkVersion and android:targetSdkVersion attributes of the uses-sdk element of AndroidManifest.xml in the APK file against the SDK version of the device or emulator. The SDK version on the device has to be greater than that required by android:minSdkVersion . In my case, since I built the package with AOSP, the target emulator has to be AOSP also. This is the relavant section in AndroidManifest.xml : <uses-sdk android:minSdkVersion="AOSP" ... And the relevant section in android.content.pm.PackageParser : if (minCode != null) { if (!minCode.equals(...

The operator instanceof returns true if the first operand is an instance of the second operand: if (a instanceof A) { // true if a is an in... If the above is true, then this is also true: A.class.isAssignableFrom(a.getClass()); The only difference is, the second operand to instanceof is the symbol for a class, not a class object: // This is OK if (a instanceof A) { Syst...

From Fedora Project wiki : A security context , or security label , is the mechanism used by SELinux to classify resources, such as processes and files, on a SELinux-enabled system. This context allows SELinux to enforce rules for how and by whom a given resource should be accessed. A security context is typically shown as a string consisting of three or four words. Each word specifies a different component of the security context, namely, the user , role , type , and level of that file or process . Each word is separated by a colon. Use the -Z switch to display security context info. Display security context for Apache files: $ ls -Z /var/www/ drwxr-xr-x. root root system_... Display security for files under...

This example captures the screen of the current Java application window, instead of the full screen. import java.io.*; import java.awt.*; import ...

This utility class retrieves SSL certificates from the server and print them out to the stdout. The output can be saved to a file and imported to a Java keystore. This is useful in your test environment where the SSL certificate is self-signed. import java.io.InputStream; import java.io.Outp... Retrieve and import the a certificate: E:\test>java RetrieveSSLCert 192.168.69.144 8081 >...