Tuesday, December 9, 2014

Install the Yeoman toolset

1. Prerequisite: Node.js and NPM should be installed in the system.

2. Install Yeoman tools
heshans@15mbp-08077.local:~/Dev$npm install --global yo bower grunt-cli

3. Check installed versions.
heshans@15mbp-08077.local:~/Dev$yo --version && bower --version && grunt --version

1.3.3

1.3.12

grunt-cli v0.1.13

Install Node.js and NPM on Mac OSX

I’m using Homebrew for the installation. If you don't have it installed, please install it.

1. Install node
heshans@15mbp-08077.local:~/Dev$brew install node

2. Check installed versions.
heshans@15mbp-08077.local:~/Dev$node -v

v0.10.33

heshans@15mbp-08077.local:~/Dev$npm -v

2.1.8

3. Update Homebrew.
heshans@15mbp-08077.local:~/Dev$brew update 

Already up-to-date.

4. Upgrade Node.
heshans@15mbp-08077.local:~/Dev$brew upgrade node

Wednesday, October 15, 2014

How to find which method called the current method at runtime


I’m using the following helper class to find which method called the current method (at runtime.)

import java.lang.reflect.Method;
import java.security.AccessController;
import java.security.PrivilegedAction;

public class TraceHelper {
    private volatile static Method m;
    private static Throwable t;

    public TraceHelper() {
        try {
            m = Throwable.class.getDeclaredMethod("getStackTraceElement", int.class);
            AccessController.doPrivileged(
                    new PrivilegedAction() {
                        public Object run() {
                            m.setAccessible(true);
                            return null;
                        }
                    }
            );
            t = new Throwable();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public String getMethodName(final int depth, boolean useNew) {
        return getMethod(depth, t != null && !useNew ? t : new Throwable());
    }

    public String getMethod(final int depth, Throwable t) {
        try {
            StackTraceElement element = (StackTraceElement) m.invoke(t, depth + 1);
            return element.getClassName() + "$" + element.getMethodName();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

}
Then I use the following code inside my aspect to get the name of the method which called my current (executing) method.
String previousMethodName = new TraceHelper().getMethodName(2, false);

Include/exclude sources when using aspect-maven-plugin


AspectJ mavn plugin will add all .java and .aj files in the project source directories by default. By using <include/> and <exclude/> tags, you can add filtering on top of that. 


            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>aspectj-maven-plugin</artifactId>
                <version>1.5</version>
                <configuration>
                    <complianceLevel>1.7</complianceLevel>
                    <source>1.7</source>
                    <target>1.7</target>

                    <sources>
                        <source>
                            <!--<basedir>src/main/java</basedir>-->
                            <!--<includes>-->
                                <!--<include>**/TransationAspect.java</include>-->
                            <!--</includes>-->
                            <excludes>
                                <exclude>**/DcXferHandler.java</exclude>
                                <!--<exclude>**/ChunkingSqlSerActor.java</exclude>-->
                            </excludes>
                        </source>
                    </sources>
                </configuration>
                <executions>
                    <execution>
                        <!--<phase>process-sources</phase>-->
                        <goals>
                            <goal>compile</goal>
                            <goal>test-compile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

Tuesday, October 14, 2014

Stackmap frame errors when building the aspectj project with Java 1.7


I had a project which used aspectj and it was building fine with Java 1.6. When I updated it to Java 1.7 I saw the following error.

[INFO] Molva the Destroyer Aspects ....................... FAILURE [2.324s]
[INFO] Molva The Destroyer Client ........................ SKIPPED
[INFO] Molva The Destroyer Parent ........................ SKIPPED
[INFO] Molva The Destroyer Distribution .................. SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.424s
[INFO] Finished at: Tue Oct 14 11:16:19 PDT 2014
[INFO] Final Memory: 12M/310M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.1:java (default) on project molva-the-destroyer-aspects: An exception occured while executing the Java class. Expecting a stackmap frame at branch target 30
[ERROR] Exception Details:
[ERROR] Location:
[ERROR] com/concur/puma/molva/aspects/TestTarget.main([Ljava/lang/String;)V @12: invokestatic
[ERROR] Reason:
[ERROR] Expected stackmap frame at this location.
[ERROR] Bytecode:
[ERROR] 0000000: 2a4d b200 5e01 012c b800 644e b800 c62d
[ERROR] 0000010: b600 ca2c 2db8 00bb 2db8 00bf 57b1 3a04
[ERROR] 0000020: b800 c62d 1904 b600 ce19 04bf
[ERROR] Exception Handler Table:
[ERROR] bci [12, 30] => handler: 30
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

My maven configuration looked like below.
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.6.5</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>org.perf4j</groupId>
            <artifactId>perf4j</artifactId>
            <version>0.9.16</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>aspectj-maven-plugin</artifactId>
                <version>1.2</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.1</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>java</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <mainClass>com.concur.puma.molva.aspects.TestTarget</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>

Fix 

The default compliance level for aspectj-maven-plugin is 1.4 according to http://mojo.codehaus.org/aspectj-maven-plugin/compile-mojo.html#complianceLevel. Since I did not have that tag specified, the build was using the default value. Once I inserted the tag into the configuration, the build was successful.

Compile aspectj project containing Java 1.7 Source


Following maven configuration let’s you compile a project with Java 1.7 source.
<dependencies>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <!--<version>1.6.5</version>-->
            <version>1.8.2</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>aspectj-maven-plugin</artifactId>
                <version>1.7</version>
                <configuration>
                    <complianceLevel>1.7</complianceLevel>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
                <executions>
                    <execution>
                        <!--<phase>process-sources</phase>-->
                        <goals>
                            <goal>compile</goal>
                            <goal>test-compile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

Tuesday, September 23, 2014

Jmeter plugins for Apache Jmeter

I came across Jmeter-plugins project today and tried it out. It has a nice set of addons to support/complement existing functionality of Jmeter.