Anemic Domain Model – resources

Fowler about the problem:
http://www.martinfowler.com/bliki/AnemicDomainModel.html

Hibernate:
http://wrschneider.blogspot.com/2005/01/avoiding-anemic-domain-models-with.html

Double Dispatch
http://stackoverflow.com/questions/227856/how-to-avoid-anemic-domain-models-and-maintain-separation-of-concerns
http://www.c2.com/cgi/wiki?DoubleDispatchExample

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Converting Maven pom.xml to SBT

Add this task to your project class.
Run reload, then pom2sbt.
Copy the output to the project file and enjoy!

lazy val pom2sbt = task {
    val deps = XML.load("pom.xml") \\ "dependencies"
    deps \"dependency" foreach( (dependency:Node) => {
      val groupId = (dependency \ "groupId").text
      val artifactId = (dependency \ "artifactId").text
      val version = (dependency \ "version").text
      val scope = (dependency \ "scope").text
      val classifier = (dependency \ "classifier").text
      val artifactValName: String = artifactId.replaceAll("[-\\.]", "_")

      print("val %s = \"%s\" %% \"%s\" %% \"%s\"".format(artifactValName, groupId, artifactId, version))
      scope match  {
        case "" => print("\n")
        case _ => print(" %% \"%s\"\n".format(scope))
      }
      None
    } )
    None
  }

How to resolve java dependency from the command line without maven

Problem

I want to be able to download java library and it’s dependencies using simple command-line tool i.e.
ivy.sh resolve jetty jetty 5.1.10

Solution

• Download Ivy. Ivy understands maven repositories and can do the job for you.
• Create a script ivy.sh in ivy installation directory with the following content:

  cd=`dirname $0`
  if [ "$1" == "resolve" ]; then
          shift
          echo "Resolving $1 $2 $3"
          java -jar $cd/ivy-2.2.0-rc1.jar -retrieve ./[artifact]-[revision]-[type].[ext] -dependency $*
  fi

• Make your script executable:
  chmod a+x ivy.sh
• Add it to the path ie. ~/.bash_profile
  export PATH=$PATH:/where/you/have/ivy.sh


Enjoy!

Gradle Cobertura Integration Revisited

Problem

I’d like to run cobertura coverage report using gradle in a non intrusive way similar to maven.
I just want to do this:

gradle cobertura

and in my script:

apply from: 'cobertura.gradle'

Current solution

There is a great solution to this problem here. It works, but is not as unintrusive and not as easy to use as I would like it to be.

My solution

This works for Gradle version 0.9-preview-1.

cobertura.gradle:

logger.info "Configuring Cobertura Plugin"

configurations{
  coberturaRuntime {extendsFrom testRuntime}
}

dependencies {
  coberturaRuntime 'net.sourceforge.cobertura:cobertura:1.9.3'
}

def serFile="${project.buildDir}/cobertura.ser"
def classes="${project.sourceSets.main.classesDir}"
def classesCopy="${classes}-copy"


task cobertura(type: Test){
  dependencies {
    testRuntime 'net.sourceforge.cobertura:cobertura:1.9.3'
  }  

  systemProperties["net.sourceforge.cobertura.datafile"] = serFile
}

cobertura.doFirst  {
  logger.quiet "Instrumenting classes for Cobertura"
  ant {
    delete(file:serFile, failonerror:false)
    delete(dir: classesCopy, failonerror:false)    
    copy(todir: classesCopy) { fileset(dir: classes) }

    taskdef(resource:'tasks.properties', classpath: configurations.coberturaRuntime.asPath)
    'cobertura-instrument'(datafile: serFile) {
      fileset(dir: classes,
              includes:"**/*.class",
              excludes:"**/*Test.class")
    }
  }
}

cobertura.doLast{
  if (new File(classesCopy).exists()) {
    ant.'cobertura-report'(destdir:"${project.reportsDir}/cobertura",
            format:'html', srcdir:"src/main/java", datafile: serFile)

    ant.delete(file: classes)
    ant.move(file: classesCopy, tofile: classes)
  }
}

And then your build.gradle could look like that:

apply plugin: 'java'
apply from: 'cobertura.gradle'
...

How to run a system command in Erlang?

Problem

I would like to be able to run ie. ls -al / from erlang and process the results using erlang. ie.

Files = cmd:run("ls -al /").


Solution

-module(cmd).
-export([run/1, run/2, test/0]).

run(Cmd) -> 
	run(Cmd, 5000).
	
run(Cmd, Timeout) ->
	Port = erlang:open_port({spawn, Cmd},[exit_status]),
	loop(Port,[], Timeout).
	
loop(Port, Data, Timeout) ->
	receive
		{Port, {data, NewData}} -> loop(Port, Data++NewData, Timeout);
		{Port, {exit_status, 0}} -> Data;
		{Port, {exit_status, S}} -> throw({commandfailed, S})
	after Timeout ->
		throw(timeout)
	end.

test() -> 
	shouldReturnCommandResult(),
	shouldThrowAfterTimeout(),
	shouldThrowIfCmdFailed(),
	{ok, "Tests PASSED"}.

shouldReturnCommandResult() ->
	"Hello\n" = run("echo Hello").

shouldThrowAfterTimeout()->
	timeout = (catch run("sleep 10", 20)).
	
shouldThrowIfCmdFailed()->
		{commandfailed, _} = (catch run("wrongcommand")),
		{commandfailed, _} = (catch run("ls nonexistingfile")).

How to download JavaDocs or sources in Maven 2?

Problem

You want to download javadocs for your depenencies into local repository to be able to use them ie. in IntelliJ.

Solution


mvn dependency:resolve -Dclassifier=javadoc
mvn dependency:resolve -Dclassifier=sources


Enjoy!

Howto compress or decompress byte array in Java?

Check this class out:

Compressor.java

import java.io.*;
import java.util.zip.*;

import org.apache.commons.io.IOUtils;

public class Compressor{
    public static byte[] compress(byte[] content){
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        try{
            GZIPOutputStream gzipOutputStream = new GZIPOutputStream(byteArrayOutputStream);
            gzipOutputStream.write(content);
            gzipOutputStream.close();
        } catch(IOException e){
            throw new RuntimeException(e);
        }
        System.out.printf("Compression ratio %f\n", (1.0f * content.length/byteArrayOutputStream.size()));
        return byteArrayOutputStream.toByteArray();
    }

    public static byte[] decompress(byte[] contentBytes){
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try{
            IOUtils.copy(new GZIPInputStream(new ByteArrayInputStream(contentBytes)), out);
        } catch(IOException e){
            throw new RuntimeException(e);
        }
        return out.toByteArray();
    }

    public static boolean notWorthCompressing(String contentType){
        return contentType.contains("jpeg")
                || contentType.contains("pdf")
                || contentType.contains("zip")
                || contentType.contains("mpeg")
                || contentType.contains("avi");
    }
}

Dependencies: Apache commons-io.jar

Hamcrest Regex Matcher

Problem

I could not find a regex matcher in hamcrest, to do ie.
assertThat(selenium.getTitle(), matches("Template T\d{3}"));

It could be that I was not looking well enough or Nat Pryce decided not to include it on purpose. Of’course I saw PatternMatcher, but it lets you build regexes rather then match against them.

Solution

So here you have, enjoy!

public class RegexMatcher extends BaseMatcher{
    private final String regex;

    public RegexMatcher(String regex){
        this.regex = regex;
    }

    public boolean matches(Object o){
        return ((String)o).matches(regex);

    }

    public void describeTo(Description description){
        description.appendText("matches regex=");
    }
    
    public static RegexMatcher matches(String regex){
        return new RegexMatcher(regex);
    }
}

HowTo customize Save As/Open dialog shortcuts in XP using windows registry

Problem:

I want to add custom shortcuts in Open/Save As dialog box in XP

Manual Solution:

Check this article by Ryan Gordon out if you want to do it manually.

Automatic Solution:

Create custom-save_as.reg file with content similar to the following:

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Comdlg32]

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Comdlg32\PlacesBar]
"Place1"="e:\\piotrga"
"Place2"="e:\\piotrga\\tmp"
"Place3"="e:\\piotrga\\Download"

Then right-click custom-save_as.reg and select "Merge" option.

Now open Save As/Open dialog and enjoy!