Checking wifi signal stregnth in ubuntu

 Use command: watch -n1 iwconfig

Then check for "Link Quality"

Example Output:

br-162f0698aa15  no wireless extensions.

enp0s31f6  no wireless extensions.

lo        no wireless extensions.

veth7f181fd  no wireless extensions.

enx482ae3bc4b7c  no wireless extensions.

docker0   no wireless extensions.

wlp61s0   IEEE 802.11  ESSID:"******"
          Mode:Managed  Frequency:5.28 GHz  Access Point: **:**:**:**:**:**
          Bit Rate=866.7 Mb/s   Tx-Power=22 dBm
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          Link Quality=51/70  Signal level=-59 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:126   Missed beacon

Ubuntu: Convert multiple images to video

Use command: ffmpeg

 example:  

ffmpeg -framerate 10 -pattern_type glob -i '*.JPG'  output4.mp4

where  '*.JPG'  means it will take all files iwth extension JPG from current directory 

"-framerate 10" mean 10 images will be shown per second

 

SpelParseException: EL1041E for maxAttemptsExpression

 SpelParseException: EL1041E  for maxAttemptsExpression  means expression is missing { or }

eg: ${max.retry.attempts

Eclipse maven update problem whike moving from older java to java17

 Errors encountered while doing maven update:

Could not get the value for parameter encoding for plugin execution default-resources

cannot resolve plugin org/apache/maven plugins maven-resources-plugin:3.1 0 

1. Close eclipse

2. Got to ~/.m2

3.  delete m2/repository/org/apache/maven

4. open eclipse 

5. update project again

(if  do not work delete whole .m2/repository)

Shopware 5 newsletter enable double opt fintionality

 https://docs.shopware.com/de/shopware-5-de/marketing-und-einkaufswelten/newsletter?utm_source=google&utm_medium=cpc&utm_campaign=nb-o04_nrt_dach_de_awareness_performance-max_lead-contact&utm_content=maxperformance&gclid=CjwKCAiAvaGRBhBlEiwAiY-yMGW-Pfxlq1TIHgN84Yrz6YgbG8-uAteR2Ex0A4Nfs0sSXWcrCst-ZRoCv5wQAvD_BwE 

 Java 17 : Unrecognized VM option 'MaxPermSize=512m'

adjust your environment variable MAVEN_OPTS and remove  MaxPermSize 

Could not bind properties to 'JacksonProperties'

Spring boot 2 run time error:

Error creating bean with name 'spring.jackson-org.springframework.boot.autoconfigure.jackson.JacksonProperties': Could not bind properties to 'JacksonProperties' : prefix=spring.jackson, ignoreInvalidFields=false, ignoreUnknownFields=true; nested exception is org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'spring.jackson.deserialization' to java.util.Map<com.fasterxml.jackson.databind.DeserializationFeature, java.lang.Boolean>

Solution:

 At application property set
 spring.jackson.deserialization.fail-on-unknown-properties: true