Saturday, March 31, 2018
Friday, March 30, 2018
Thursday, March 29, 2018
JPA detached entity passed to persist error
- https://notesonjava.wordpress.com/2008/11/03/managing-the-bidirectional-relationship/
- https://stackoverflow.com/questions/13370221/jpa-hibernate-detached-entity-passed-to-persist
- https://github.com/SomMeri/org.meri.jpa.tutorial/blob/master/src/main/java/org/meri/jpa/relationships/entities/bestpractice/SafePerson.java
- http://meri-stuff.blogspot.in/2012/03/jpa-tutorial.html#RelationshipsBidirectionalOneToManyManyToOneConsistency
Wednesday, March 28, 2018
Tuesday, March 27, 2018
spring boot rest api
- http://websystique.com/spring-boot/spring-boot-rest-api-example/
- https://www.codesandnotes.be/2014/10/31/restful-authentication-using-spring-security-on-spring-boot-and-jquery-as-a-web-client/
- https://stackoverflow.com/questions/38974428/jquery-alerts-undefined-on-error-instead-of-java-spring-exception-details
- https://stackoverflow.com/questions/7952154/spring-resttemplate-how-to-enable-full-debugging-logging-of-requests-responses
Spring boot exception handling
- https://www.toptal.com/java/spring-boot-rest-api-error-handling
- http://www.springboottutorial.com/spring-boot-exception-handling-for-rest-services
- https://dzone.com/articles/global-exception-handling-with-controlleradvice
- https://stackoverflow.com/questions/28902374/spring-boot-rest-service-exception-handling
debugging json
- https://notes.georgboe.com/post/debug-http-400-errors-in-spring-mvc/
- https://stackoverflow.com/questions/7952154/spring-resttemplate-how-to-enable-full-debugging-logging-of-requests-responses
- https://pubs.vmware.com/vfabric51/index.jsp?topic=/com.vmware.vfabric.vas.1.0/vas/api-vfabric-docs.html
- https://stackoverflow.com/questions/38974428/jquery-alerts-undefined-on-error-instead-of-java-spring-exception-details
contribution required
- apache
- JSR
- shopizer
- eclipse
- firefox
- mdn
- tomcat
- spring
- hibernate
- android
Monday, March 26, 2018
debugging in browser
- https://developer.mozilla.org/en-US/docs/Tools/Network_Monitor
- https://stackoverflow.com/questions/39228657/disable-chrome-strict-mime-type-checking
- right click on web page
- choose inspect element
- click on network
- now reload the page or click on submit and check the data
- https://stackoverflow.com/questions/819213/how-to-debug-javascript-error
domain modellig techniques
- https://www.infoq.com/articles/seven-modelling-smells
- https://www.scaledagileframework.com/domain-modeling/
- http://www.mindscapehq.com/documentation/lightspeed/Domain-Modelling-Techniques
- Handle one requirement at a time
- Think about the reports required
Sunday, March 25, 2018
Saturday, March 24, 2018
next
- JPA
- mapping inner class
- mapping inner interface
- save data in database
- apply dynamic fileds functionality in registration
- accept the values into collection
- save the values in database
- validation
- check for duplicacy
- type conversion
- all the form should be populated with values from database. not the present case where values are hardcoded.
- applying sms gateway
- mobile verification through otp
- apply reactjs
- apply redux with reactjs
doubt is out
- accepting multiple values e.g mobile numbers in to a collection
Friday, March 23, 2018
regular expression requirement for the validation
- landline number
- country code
- youtube video url
- adhar id
- pin code
- city
- state
- country
- image URL
- dateofbirth
- bride(min 18 years max 60 years)
- groom(min 21 years max 65 years)
- quaification
- occupation
- address
Thursday, March 22, 2018
spring boot hibernate validator dependency
spring boot starter web dependency already includes hibernate validator dependency.
Spring MVC validation
- spring boot starter web dependency already includes hibernate validator dependency.
- https://www.journaldev.com/2668/spring-validation-example-mvc-validator
- http://technicalstack.com/form-validation-part-4-using-annotation-pattern-past-max-etc/
- https://stackoverflow.com/questions/3813195/regular-expression-for-indian-mobile-numbers
- mobile no validation
- birthdate validation for correct range which dependes on gender
- email validation
- https://docs.oracle.com/javase/tutorial/essential/regex/intro.html
Tuesday, March 13, 2018
showing the newly created page on blogger
- pages
- new page
- publish the page
- Layout
- cross column
- edit
- select the newly created page
- choose save
solving programming problem speedily
- remember God
- pranayam
- write down the summary of the problem
- split the problem into milestones
- achieve one milestone at a time
- note down the sample input and output
- use white plain paper for dry run
- use pencil and rubber for dry run
- use meaningful variable names
- write down what should happen on each milestone or event
- dont exceed time limit
- always check or test the code for compile time error and run time error and prescribed time limit for compilation
- never give up till last moment
- results dont matter but efforts do
- note down the lessons you learnt and your shortcomings
- work on your weakness
- https://www.quora.com/What-is-the-mathematical-background-necessary-for-competitive-programming
- https://www.quora.com/What-are-some-must-know-topics-in-discrete-math-and-probability-for-competitive-programming
Monday, March 12, 2018
enterprise service bus mule
- https://www.mulesoft.com/resources/esb/what-mule-esb
- https://stackoverflow.com/questions/3792519/apache-camel-and-other-esb-products
- go for apache project instead of closed community mulesoft's mule
Java Companies
- oracle
- amazon
- apache
- red hat
- ibm
- sap
- thoughtworks
Project related questions
- user defined annotation
- payload
- what is the use of dto?
- validation
- type conversion
Sunday, March 11, 2018
debugging web app in web browser
- use chrome
- remove required attribute for fast debugging
- https://stackoverflow.com/questions/22148080/an-invalid-form-control-with-name-is-not-focusable
explore
- python
- tensorflow
- ros(robotic OS)
- kotlin
- reactive system
- reactive programming
- kafka
Saturday, March 10, 2018
DOM
- each web page has separate dom
- dom has dynamic property attached to elements
- https://css-tricks.com/dom/
current problem
- html
- css
- javascript
- json
- bootstrap
- jquery
- parse.JSONresponse.error
- $post
- $each
- event.preventdefault
- window.location.href = serverContext + "login?message=" + data.responseJSON.message;
- $.each( errors, function( index,item ){
$("#globalError").show().append(item.defaultMessage+"<br/>");
}); - /*<![CDATA[*/
- /*]]>*/
- th:inline="javascript"
- $(":password").keyup(function(){
if($("#password").val() != $("#matchPassword").val()){
$("#globalError").show().html(/*[[#{PasswordMatches.user}]]*/);
}else{
$("#globalError").html("").hide();
}
}); - .fail() method
- is it chaining ie fail getting called after post?
- https://api.jquery.com/deferred.fail/
- flow of execution in jquery
- javascript debugging
- jquery debugging
- setting breakpoints in jquery
Friday, March 9, 2018
jquery
- serialize function
- what if there are multiple ready function?
- debugging
- all function must return
- unique id of elements
- event execution order
- https://stackoverflow.com/questions/10638059/javascript-debugging-line-by-line-using-google-chrome
Thursday, March 8, 2018
microservice
- Microservices is an approach to application development in which a large application is built as a suite of modular services. Each module supports a specific business goal and uses a simple, well-defined interface to communicate with other sets of services.
- Microservices must be independently deployable, whereas SOA services are often implemented in deployment monoliths. ... So, SOA is an architectural pattern in which application components provide services to other components. However, in SOA those components can belong to the same application.
- https://en.wikipedia.org/wiki/Microservices
Wednesday, March 7, 2018
codejam
- https://icpc.baylor.edu/
- https://www.geeksforgeeks.org/prepare-google-kickstart/
- https://www.quora.com/What-is-a-good-way-to-prepare-for-Google-Code-Jam
- https://code.google.com/codejam/resources/problem-preparation
- https://groups.google.com/forum/#!topic/google-code/0mzXncavvtM
- https://www.youtube.com/watch?v=klXNkEdR1cY
- Good Math is the first thing
- Algorithm
- Time Complexity
- Data Structure
- book -> competitive programming
- Practice Practice and Practice
- learn all the shortcuts of IDE
- learn typing
- Reasoning
- Puzzles
- https://fossbytes.com/google-code-jam-2015-heres-everything-you-should-know-to-participate/
- https://blog.codingblocks.com/2017/howto-prepare-google-apac-acmicpc
- taking coding course at
- Coursera
- Competitive Coding Bootcamp.
- regular expression
- file handling
- https://news.ycombinator.com/item?id=801835
- https://stackoverflow.com/questions/2228402/being-able-to-solve-google-code-jam-problem-sets
- http://jugglingcode.blogspot.in/2012/06/tipsstrategy-for-google-code-jam.html
- techgig
- codechef
- topcoder
- codeforce
- https://code.google.com/codejam/resources/faq
- https://code.google.com/codejam/terms
- https://stackoverflow.com/questions/2228402/being-able-to-solve-google-code-jam-problem-sets
- ACM-ICPC
Tuesday, March 6, 2018
unresolved
- JPA
- onetoone (targetentity)
- If we did, we would need to specify the type of entity that will be stored in the
Collection that is needed by the persistence provider. The code is shown in Listing 4-21 and looks
almost identical, except for the targetEntity element that indicates the entity type. - set vs list to guarantee the uniqueness of elements in collection
- validation
- cascade
- domain modelling correction
spring data jpa one to many example
java finding the run time options related to jre
- java -XshowSettings
- java -X
Interesting Projects
- Finding the originator of a fb post that has gone viral using fb api
- deciphering the geo coordinates from ip address
- programmatically accessing whatsapp messages and automatically deleting the irrelevant content based on specified criteria and storing the relevant content onto the free online databases and sending their links as email
logstash
- Logstash is an open source tool for collecting, parsing, and storing logs for future use. Kibana 3 is a web interface that can be used to search and view the logs that Logstash has indexed. Both of these tools are based on Elasticsearch. Elasticsearch, Logstash, and Kibana, when used together is known as an ELK stack.
- https://www.elastic.co/products/logstash
Interesting book to build linux appliance
Linux Appliance Design: A Hands-on Guide to Building Linux Appliances
By Bob Smith, John Hardin, Graham Phillips
Monday, March 5, 2018
preventing cutting off stack traces
- https://stackoverflow.com/questions/11865307/how-to-expand-size-of-java-stack-trace-to-see-bottom-of-stack-triggering-a-sta
- http://apache-logging.6191.n7.nabble.com/Q-how-to-prevent-log4j-from-cutting-off-stack-traces-td9011.html
- https://www.wowza.com/community/questions/7108/truncated-exception-stack-traces.html
- https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-2.html
- http://stas-blogspot.blogspot.in/2011/07/most-complete-list-of-xx-options-for.html
- http://www.brendangregg.com/FlameGraphs/cpuflamegraphs.html
- https://dzone.com/articles/configuring-logback-with-spring-boot
- https://docs.spring.io/spring-boot/docs/current/reference/html/howto-logging.html
- Strategy
- Virtual Machine
- Embedded Tomcat
- Logging Framework (logback)
- JPA
- Spring
Java Performance Tuning
- https://dzone.com/articles/java-performance-tuning
- https://blog.oio.de/2014/03/07/java-profilers-a-short-comparison-between-jprofiler-yourkit-and-javas-visualvm/
- memory footprint of the application
- dump
- jni call
JPA Annotations
- https://www.objectdb.com/api/java/jpa/PrePersist
- A callback method is a method that we do not call
- it is called by the framework
- Prepersist is a marker annotation
Project skill required
- Spring data JPA
- JPA
- Spring boot
- Hibernate
- MySQL
- Spring MVC
- Thymeleaf
- Spring Security
- Jquery
- Bootstrap
- CSS
- HTML
- JSON
- AWS
- Android
- CI/CD
Sunday, March 4, 2018
reading aloud a pdf in windows 10
- Just double click on a pdf file and then choose read aloud option above
- it will start reading aloud the book
Image editing
- adding watermark to an image
- adding logo to an image
- removing watermark from an image
- removing logo from an image
- cropping
- changing the background
- changing the color
obtaining radio button value
We can pass any value through radio button just we need to mention the value in the value attribute
Saturday, March 3, 2018
Tool
- SourceTree
- GUI git tool
- Oracle SQL Developer( for interacting with Oracle)
Video Editing through da vinci resolve 14
- https://www.blackmagicdesign.com/products/davinciresolve/training
- terms
- bit rate
- encoding
- transcoding
- color correction
- https://www.youtube.com/watch?v=UMAApAZExSc
- codec
- coder
- decoder
- waveform
- pal
- ntsc
- video formats
- converting one format to the other
- download the avc video converter
- When I converted .avi file of size 977 mb into .mp4 format its size got reduced to 119 mb
- when i converted .avi to .mp4 format, it was recognized by da vinci resolve 14
- milestones
- extracting audio from a video
- video cutting
- removing logo from image
- removing lower/front/right/left part from image
- adding logo to a video
- mixing two videos
- adding text to a video
- adding image to a video
- adding a thumbnail to a video
- adding subtitles to a video
- color correction
- video editing softwares
- after effects or blackmagic design's fusion
- premiere pro or da vinci resolve 14
- blender
- final cut
- da vinci 14
- timeline
- ripple cut
- ripple delete
- clip
- https://blender.stackexchange.com/questions/8864/how-to-reduce-the-output-video-size
- https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=36717
- http://www.pavtube.com/upload-davinci-resolve-video.html
Friday, March 2, 2018
Thursday, March 1, 2018
import or push to github repository in eclipse IDE
first we need to create repository with github. It can be public or private.
Steps for IDE (eclipse or STS)->
File
->import
->projects from github
-> clone URI
now copy the clone URI and paste in to box of the IDE
enter the credentials ie user name and password
do not enter any port number
commiting to the github
now make changes in the project
right click and choose team
add to index
commit
enter message and click on commit
=====================================
We can import public github repository to our own repository. and make it private.
and then import the project and choose clone uri into Spring tool Suite.
if there is any error->
right click on the project and maven -> update project-> force update
make changes in the project
add to index
commit
enter message and click on commit and push
Steps for IDE (eclipse or STS)->
File
->import
->projects from github
-> clone URI
now copy the clone URI and paste in to box of the IDE
enter the credentials ie user name and password
do not enter any port number
commiting to the github
now make changes in the project
right click and choose team
add to index
commit
enter message and click on commit
=====================================
We can import public github repository to our own repository. and make it private.
and then import the project and choose clone uri into Spring tool Suite.
if there is any error->
right click on the project and maven -> update project-> force update
make changes in the project
add to index
commit
enter message and click on commit and push
AWS Precautions
AWS beanstalk with rds
while we delete the environments aws creates the snapshots that take up 5 gb each. so I had to pay around 7$ even though I was in free tier just because of this.
So please be careful .
I changed the backup retention period to 0 then all the snapshots got deleted.
and applied the changes immediately
while we delete the environments aws creates the snapshots that take up 5 gb each. so I had to pay around 7$ even though I was in free tier just because of this.
So please be careful .
I changed the backup retention period to 0 then all the snapshots got deleted.
and applied the changes immediately
Destination Skill
- NoSQL
- Microservices
- AWS
- EC2
- Loadbalancing
- Github
- Team Working
- CI and Jenkins
- Travis
- CircleCI
- Code Deploy
- CD
- Testing
- UML
- Algorithm
- Data Structure
- Profiling
- JVM Performance tuning
- Effective Java
- Certification test
- Maven
- Gradle
- Android
- NDK
- Spring 5
- Spring Security 5
- Spring boot
- Spring data JPA
- JSF
- WebServices
- SOAP
- XML
- DBA certification
- MySQL
- Queries
- CodeJam
- CodeChef
- Techgig
- guru
- odesk
- upwork
- committing to Apache Project
- committing to Shopizer
- committing to eclipse
- Java Expert group
- Groovy
- Grails
- Hibernate
- HTML
- CSS
- JavaScript
- JQuery
- Bootstrap
- JSON
- geeksforgeeks
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