Using Redis cache

Installation:

Follow the instruction at: Install Redis cache in linux - DigitalOcean

Using Redis cache:

Create bean:
<bean id="jedisConnFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
          p:hostName="${atm.cache.redis.host}"
          p:port="${atm.cache.redis.port}"
          p:poolConfig-ref="jedisPoolConfig"
          p:usePool="true"/>
 <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate"
          p:connectionFactory-ref="jedisConnFactory" p:keySerializer-ref="stringRedisSerializer"/>

 Autowired in java implement:
@Autowired
private RedisTemplate<String, ProgramBasicInfo> programRedisTemplate;

Delete all cache: (in this case, it get connection and then flush all data)
programRedisTemplate.getConnectionFactory().getConnection().flushAll();

Delete cache:
programRedisTemplate.opsForHash().getOperations()
                                    .delete(Constants.CACHE_PROGRAM_GUIDE_KEY);

Put data to cache:
programRedisTemplate.opsForHash().put(Constants.CACHE_PROGRAM_GUIDE_KEY, program.getProgramId(),       programBasicInfo);

Get data from cache:
(ProgramBasicInfo) programRedisTemplate.opsForHash().get(Constants.CACHE_PROGRAM_GUIDE_KEY, programId);

References:

http://blog.joshuawhite.com/java/caching-with-spring-data-redis/
http://caseyscarborough.com/blog/2014/12/18/caching-data-in-spring-using-redis/

Synchronize SimpleDateFormat object in Java

SimpleDateFormat object does not work properly in a multi threaded environment. It may output a wrong date when parsing. So the safest way is to synchronize it.

private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
public String formatDate(Date d) {
    synchronized(sdf) {
        return sdf.format(d);
    }
}

Hope that help.

Check if a class is loaded and lib file location in JVM

Example below is to see if JVM using ojdbc6 version 11 or version 12.

final ClassLoader loader = Thread.currentThread().getContextClassLoader();
ClassPath clazzPath = ClassPath.from(loader);
Set<ClassInfo> classes = clazzPath.getTopLevelClasses();
for (final ClassPath.ClassInfo classInfo : classes) {
    if (classInfo.getName().startsWith("oracle")) {
         if (classInfo.getName().contains("oracle.jdbc.babelfish")) {
                 isVersion12 = true;
         }
    }
}
            
if(isVersion12) {
        LOGGER.info("Ojdbc version 12");
} else {
        LOGGER.info("Ojdbc version 11");
}

Class klass = OracleConnection.class;
URL location = klass.getResource('/' + klass.getName().replace('.',  '/') + ".class");
LOGGER.info(location.toString());

Read package name and version from Manifest file

Bean: 

public class BuildVersion {
   
    /** The build name. */
    private String buildName;
   
    /** The version. */
    private String version;

    /**
     * Gets the version.
     *
     * @return the version
     */
    public String getVersion() {
        return version;
    }

    /**
     * set version.
     *
     * @param version the new version
     */
    public void setVersion(String version) {
        this.version = version;
    }

    /**
     * Gets the builds the name.
     *
     * @return the builds the name
     */
    public String getBuildName() {
        return buildName;
    }

    /**
     * Sets the builds the name.
     *
     * @param buildName the new builds the name
     */
    public void setBuildName(String buildName) {
        this.buildName = buildName;
    }
}

VersionServiceImpl:

private BuildVersion getBuildVersion() {
        BuildVersion buildVersion = new BuildVersion();

        Class clazz = this.getClass();
        String className = clazz.getSimpleName() + ".class";
        String classPath = clazz.getResource(className).toString();
        try {
            String manifestPath = classPath.substring(0, classPath.lastIndexOf("/WEB-INF")) +
                    "/META-INF/MANIFEST.MF";
            Manifest manifest = new Manifest(new URL(manifestPath).openStream());
            Attributes attr = manifest.getMainAttributes();
            String title = attr.getValue("Specification-Title");
            String version = attr.getValue("Specification-Version");

            buildVersion.setBuildName(title);
            buildVersion.setVersion(version);
        } catch (Exception ex) {
            LOGGER.error(ex.getMessage(), ex);
        }
        return buildVersion;
    }

VersionEndpoint:

@Component
@Path ("/")
public class VersionEndpoint {
   
    /** The version service. */
    @Autowired
    private VersionService versionService;
   
    /**
     * getVersion service use to retrieve the current release version.   
     *
     * @param format the format
     * @return Version response
     */
    @GET
    @Path ("/version")
    @Produces ({ MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON })
    public Response getVersion(@DefaultValue (WSConstants.RESPONSE_TYPE_JSON) @QueryParam ("format") String format) {
        try {
            return Response.ok().entity(versionService.getVersion()).type(WSUtil.getWSResponseType(format)).build();
        } catch (Exception e) {
            return Response.ok().entity("Error: "  + e.getMessage()).type(WSUtil.getWSResponseType(format)).build();
        }       
    }                                       
}

Install Ibus-unikey in Linux for Vietnamese

Uninstall all preinstalled ibus package and its dependencies

    sudo apt-get remove --auto-remove ibus

Purging config/data too

    sudo apt-get purge --auto-remove ibus

Maybe restart is needed.

Install new ibus-unikey

    sudo apt-get install ibus-unikey

After installing done, run:

    ibus-setup

to open Ibus Preferences. 

Choose Input method tab, check 'Customize active input methods'. In selection box, click Show all input methods, choose Vietnamese->Unikey.

Logout your system to active the new input method.

Now in top right corner of your screen, you are able to select 'Unikey' to input Vietnamese.

Some good Linux scripts

Change test in file

sed -i s/helloword/HELLOWORLD/g file.txt

Copy file from Linux server to Linux server

scp source_file_name username@destination_host:destination_folder
     or
scp [-r] [[user1@]hostname1:]file1 ... [[user2@]hostname2:]file2

Ex:
scp pluto:/home/jones/letter.doc .
copy the file letter.doc from the /home/jones directory of the remote system pluto to the working directory on the local system 

scp notice.doc pluto:/home/jones
copy the file notice.doc from current directory of the local system to the /home/jones directory of the remote system, pluto

Find file match name in a folder

cd <your-folder>
for f in *; do
        case $f in
                abc*.xml)
                        echo $f
                        ;;
                def*.xml)
                        echo $f
                        ;;
        esac
done

Check file is open in linux

Check if file prefix by 'filename' is open by 'cp' process:

while :
do
    if [[ `lsof -c cp | grep filename*.xml` ]]
    then
    printf ".";
    sleep 0.5
       
    else
        break   
    fi
done
    echo "Done!"

Auto deploy script for Weblogic

Some Configuration (deploy.conf)

#Enter the package location here
source=/data/Jenkins_builds/MMT
#Enter the server IP here
FEServer=<fronend-ip-server>
BEServer=<backend-ip-server>

#Enter the target name here
FETarget=Server-0
BETarget=Server-2

#Enter package name
FEPackage=atm-ui-portlet
BEPackage=mmt-ws

#Enter the source path here
FEPath=/data/deployment/portal_destination
BEPath=/data/deployment

#Enter the portal deploy path here
PortalDeploy=/data/deployment/portal_deploy

Auto deploy script

#!/bin/bash
Logfile="logAutoDeploy.txt"

. ./deploy.conf

echo [$(date)]: ============Starting to auto deploy========== >> $Logfile

if [ -f $source/$BEPackage.war ]; then
    echo [$(date)]: ============Deploy Backend package========== >> $Logfile
    echo undeploy the package $BEPackage
    java -classpath /data/weblogic/wlserver_10.3/server/lib/weblogic.jar  weblogic.Deployer -adminurl t3://$BEServer:7001 -user <user-name> -password <password> -undeploy -name $BEPackage
    echo the package $BEPackage is undeployed >> $Logfile

    echo delete the package $BEPath/$BEPackage >> $Logfile
    cd $BEPath
    rm -rf $BEPackage

    mkdir $BEPackage
    cd $BEPackage

    echo copy $BEPackage package to $BEPath/$BEPackage >> $Logfile
    cp $source/$BEPackage.war ./
   
    echo unzip $BEPackage package >> $Logfile
    unzip $BEPackage.war
    rm -f $BEPackage.war
    echo deploy $BEPackage to back end server >> $Logfile
    java -classpath /data/weblogic/wlserver_10.3/server/lib/weblogic.jar  weblogic.Deployer -adminurl t3://$BEServer:7001 -user <user-name> -password <password> -deploy $BEPath/$BEPackage -targets $BETarget

    echo remove $BEPackage war file in Jenkins build >> $Logfile
    cd $source
    mv $BEPackage.war tmp
fi

if ls $source/$FEPackage* 1> /dev/null 2>&1; then
    echo [$(date)]: ============Deploy Frontend package========== >> $Logfile
    echo undeploy the package $FEPackage >> $Logfile
    java -classpath /data/weblogic/wlserver_10.3/server/lib/weblogic.jar  weblogic.Deployer -adminurl t3://$FEServer:7001 -user <user-name> -password <password> -undeploy -name $FEPackage
    echo the package $FEPackage is undeployed >> $Logfile

    echo delete the package $FEPackage >> $Logfile
    cd $FEPath
    rm -rf $FEPackage*

    echo copy the $FEPackage to $PortalDeploy >> $Logfile
    scp $source/$FEPackage* $PortalDeploy
    echo waiting to Liferay extracts the package >> $Logfile
    sleep 10
      
    echo deploy $FEPackage to server >> $Logfile
    java -classpath /data/weblogic/wlserver_10.3/server/lib/weblogic.jar  weblogic.Deployer -adminurl t3://$FEServer:7001 -user <user-name> -password <password> -deploy $FEPath/$FEPackage -targets $FETarget   

    echo remove $FEPackage war file in Jenkins build >> $Logfile
    cd $source
    mv $FEPackage* tmp
fi