Thursday, October 16, 2014

Failed to execute goal maven-compiler-plugin:2.5.1:compile (default-compile) javac: invalid target release: 1.7

http://dhruba.name/2008/12/22/compiling-java-16-projects-using-maven-on-mac-os-x/

The reason is that the following environment variable isn’t set by default.
export JAVA_HOME="/System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home"






[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.5.1:compile (default-compile) on project rcfw-orm: Compilation failure
[ERROR] Failure executing javac, but could not parse the error:
[ERROR] javac: invalid target release: 1.7
[ERROR] Usage: javac <options> <source files>
[ERROR] use -help for a list of possible options
[ERROR] -> [Help 1]


Tech Blogs for Reading

Single Url : http://www.one-tab.com/page/B_-C5fVyTMu2u2WEIZSdAQ

http://sumit-techblog.blogspot.com/2014/10/java-architect-interview-preparation.html | Technical Blog: Java Architect Interview Preparation
http://www.javacodegeeks.com/2014/07/integrate-apps-with-neo4j-using-zapier.html | Integrate apps with Neo4j using Zapier | Java Code Geeks
http://www.javacodegeeks.com/2014/07/jaxb-a-newcomers-perspective-part-1.html | JAXB – A Newcomer’s Perspective, Part 1 | Java Code Geeks
http://www.javacodegeeks.com/2014/07/how-to-instantly-improve-your-java-logging-with-7-logback-tweaks.html | How to Instantly Improve Your Java Logging With 7 Logback Tweaks | Java Code Geeks
http://www.javacodegeeks.com/2014/07/sonarqube-as-an-education-platform.html | SonarQube As An Education Platform | Java Code Geeks
http://www.javacodegeeks.com/2014/07/use-cases-for-elasticsearch-flexible-query-cache.html | Use Cases for Elasticsearch: Flexible Query Cache | Java Code Geeks
http://www.javacodegeeks.com/2014/07/template-method-pattern-example-using-java-generics.html | Template Method Pattern Example Using Java Generics | Java Code Geeks
http://www.javacodegeeks.com/2014/07/how-to-compose-html-emails-in-java-with-spring-and-velocity.html | How to compose html emails in Java with Spring and Velocity | Java Code Geeks
http://www.javacodegeeks.com/2014/07/java-ee-7-with-angular-js-part-1.html | Java EE 7 with Angular JS – Part 1 | Java Code Geeks
http://www.javacodegeeks.com/2014/07/a-beginners-guide-to-jpahibernate-entity-state-transitions.html | A beginner’s guide to JPA/Hibernate entity state transitions | Java Code Geeks
http://www.javacodegeeks.com/2014/08/avoiding-null-checks-in-java.html | Avoiding Null Checks In Java | Java Code Geeks
http://www.javacodegeeks.com/2014/08/my-exprience-using-elasticsearch-nodejs-and-expressjs.html | My Exprience using ElasticSearch NodeJS and ExpressJS | Java Code Geeks
http://www.javacodegeeks.com/2014/08/tutorial-rest-api-design-and-implementation-in-java-with-jersey-and-spring.html | Tutorial – REST API design and implementation in Java with Jersey and Spring | Java Code Geeks
http://www.javacodegeeks.com/2014/08/deploying-a-spring-boot-application-to-cloud-foundry-with-spring-cloud.html | Deploying a Spring boot application to Cloud Foundry with Spring-Cloud | Java Code Geeks
http://www.javacodegeeks.com/2014/08/hibernate-statistics-with-hawtio-and-jolokia.html | Hibernate Statistics with Hawtio and Jolokia | Java Code Geeks
http://www.javacodegeeks.com/2014/08/getting-a-list-of-available-cryptographic-algorithms.html | Getting A List of Available Cryptographic Algorithms | Java Code Geeks
http://www.javacodegeeks.com/2014/08/but-im-negotiable.html | But I’m negotiable | Java Code Geeks
http://www.javacodegeeks.com/2014/08/decorator-design-pattern-applied.html | Decorator Design Pattern Applied | Java Code Geeks
http://www.javacodegeeks.com/2014/08/hawtio-on-jboss-eap-part-ii.html | HawtIO on JBoss EAP (Part II) | Java Code Geeks
http://www.javacodegeeks.com/2014/08/java-ee-asynchronous-constructs-and-capabilities.html | Java EE: Asynchronous constructs and capabilities | Java Code Geeks
http://www.javacodegeeks.com/2014/08/builder-design-pattern-applied.html | Builder Design Pattern Applied | Java Code Geeks
http://www.javacodegeeks.com/2014/08/osgi-the-gateway-into-micro-services-architecture.html | OSGi: the gateway into micro-services architecture | Java Code Geeks
http://www.javacodegeeks.com/2014/08/try-optimising-the-memory-consumption-first.html | Try optimising the memory consumption first | Java Code Geeks
http://www.javacodegeeks.com/2014/08/command-design-pattern-applied.html | Command Design Pattern Applied | Java Code Geeks
http://www.javacodegeeks.com/2014/08/how-to-negotiate-your-salary.html | How to Negotiate Your Salary | Java Code Geeks
http://www.javacodegeeks.com/2014/08/understanding-volatile-via-example.html | Understanding volatile via example | Java Code Geeks
http://www.javacodegeeks.com/2014/08/autoboxing-unboxing-and-nosuchmethoderror.html | Autoboxing, Unboxing, and NoSuchMethodError | Java Code Geeks
http://www.javacodegeeks.com/2014/08/java-concurrency-tutorial-atomicity-and-race-conditions.html | Java Concurrency Tutorial - Atomicity and race conditions | Java Code Geeks
http://www.javacodegeeks.com/2014/08/15-java-socket-programming-networking-interview-questions-and-answers.html | 15 Java Socket Programming, Networking Interview Questions and Answers | Java Code Geeks
http://www.javacodegeeks.com/2014/08/pizza-problem-builder-vs-decorator.html | Pizza problem - builder vs decorator | Java Code Geeks
http://www.javacodegeeks.com/2014/08/this-is-stuff-junit-dynamic-tests-generation.html | This is Stuff: jUnit: Dynamic Tests Generation | Java Code Geeks
http://www.javacodegeeks.com/2014/08/java-concurrency-tutorial-visibility-between-threads.html | Java Concurrency Tutorial - Visibility between threads | Java Code Geeks
http://www.javacodegeeks.com/2014/08/programming-language-job-trends-part-1-august-2014.html | Programming Language Job Trends Part 1 – August 2014 | Java Code Geeks
http://www.javacodegeeks.com/2014/09/the-next-it-revolution-micro-servers-and-local-cloud.html | The next IT revolution: micro-servers and local cloud | Java Code Geeks
http://www.javacodegeeks.com/2014/09/5-things-i-do-to-stay-relevant.html | 5 Things I Do to Stay Relevant | Java Code Geeks
http://www.javacodegeeks.com/2014/09/analysing-the-performance-degradationimprovements-of-a-java-ee-application-with-interceptors.html | Analysing the performance degradation/improvements of a Java EE application with interceptors | Java Code Geeks
http://www.javacodegeeks.com/2014/09/secure-rest-services-using-spring-security.html | Secure REST services using Spring Security | Java Code Geeks
http://www.javacodegeeks.com/2014/09/everything-developers-need-to-know-about-xpaas.html | Everything Developers Need To Know About xPaaS | Java Code Geeks
http://www.javacodegeeks.com/2014/09/programming-language-job-trends-part-2-august-2014.html | Programming Language Job Trends Part 2 - August 2014 | Java Code Geeks
http://www.javacodegeeks.com/2014/09/jaxb-a-newcomers-perspective-part-2.html | JAXB – A Newcomer’s Perspective, Part 2 | Java Code Geeks
http://www.javacodegeeks.com/2014/09/use-cases-for-elasticsearch-geospatial-search.html | Use Cases for Elasticsearch: Geospatial Search | Java Code Geeks
http://www.javacodegeeks.com/2014/09/why-you-should-control-visibility-of-class-and-interface-in-java.html | Why you should control Visibility of Class and Interface in Java | Java Code Geeks
http://www.javacodegeeks.com/2014/09/garbage-collectors-serial-vs-parallel-vs-cms-vs-g1-and-whats-new-in-java-8.html | Garbage Collectors – Serial vs. Parallel vs. CMS vs. G1 (and what’s new in Java 8) | Java Code Geeks
http://www.javacodegeeks.com/2014/09/memory-leaks-measuring-frequency-and-severity.html | Memory leaks – measuring frequency and severity | Java Code Geeks
http://www.javacodegeeks.com/2014/09/programming-language-job-trends-part-3-august-2014.html | Programming Language Job Trends Part 3 – August 2014 | Java Code Geeks
http://www.javacodegeeks.com/2014/09/angularjs-tutorial-getting-started-with-angularjs.html | AngularJS Tutorial: Getting Started with AngularJS | Java Code Geeks
http://www.javacodegeeks.com/2014/09/jvm-permgen-where-art-thou.html | JVM PermGen – where art thou? | Java Code Geeks
http://www.javacodegeeks.com/2014/09/high-availability-design.html | High availability design | Java Code Geeks
http://www.javacodegeeks.com/2014/09/java-method-logging-with-aop-and-annotations.html | Java Method Logging with AOP and Annotations | Java Code Geeks
http://www.javacodegeeks.com/2014/09/java-9-the-ultimate-feature-list.html | Java 9 – The Ultimate Feature List | Java Code Geeks
http://www.javacodegeeks.com/2014/09/what-sonarqube-is-not.html | What SonarQube Is NOT | Java Code Geeks
http://www.javacodegeeks.com/2014/09/a-classloading-mystery-solved.html | A classloading mystery solved | Java Code Geeks
http://www.javacodegeeks.com/2014/09/3-examples-of-parsing-html-file-in-java-using-jsoup.html | 3 Examples of Parsing HTML File in Java using Jsoup | Java Code Geeks
http://www.javacodegeeks.com/2014/09/use-cases-for-elasticsearch-index-and-search-log-files.html | Use Cases for Elasticsearch: Index and Search Log Files | Java Code Geeks
http://www.javacodegeeks.com/2014/09/the-measure-of-success.html | The Measure Of Success | Java Code Geeks
http://www.javacodegeeks.com/2014/09/processing-java-annotations-using-reflection.html | Processing Java Annotations Using Reflection | Java Code Geeks
http://www.javacodegeeks.com/2014/09/maven-common-problems-and-pitfalls.html | Maven Common Problems and Pitfalls | Java Code Geeks
http://www.javacodegeeks.com/2014/09/jpa-tutorial-mapping-entities-part-1.html | JPA tutorial: Mapping Entities – Part 1 | Java Code Geeks
http://www.javacodegeeks.com/2014/09/jquery-ajax-servlets-integration-building-a-complete-application.html | jQuery Ajax – Servlets Integration: Building a complete application | Java Code Geeks
http://www.javacodegeeks.com/2014/09/embedding-a-xmpp-server-inside-your-jsf-web-application-using-vysper-tomee-and-primefaces.html | Embedding a XMPP server inside your JSF Web Application using Vysper, TomEE and PrimeFaces | Java Code Geeks
http://www.javacodegeeks.com/2014/09/built-in-fake-objects.html | Built-in Fake Objects | Java Code Geeks
http://www.javacodegeeks.com/2014/09/one-jar-to-rule-them-all-apache-tomee-shrinkwrap-javaee-boot.html | One Jar To Rule Them All: Apache TomEE + Shrinkwrap == JavaEE Boot | Java Code Geeks
http://www.javacodegeeks.com/2014/09/apache-camel-for-micro%c2%adservice-architectures.html | Apache Camel for Micro­service Architectures | Java Code Geeks
http://www.javacodegeeks.com/2014/09/optional-and-objects-null-pointer-saviours.html | Optional and Objects: Null Pointer Saviours! | Java Code Geeks
http://www.javacodegeeks.com/2014/09/embedded-jetty-and-apache-cxf-secure-rest-services-with-spring-security.html | Embedded Jetty and Apache CXF: secure REST services with Spring Security | Java Code Geeks
http://www.javacodegeeks.com/2014/09/the-fastest-way-of-drawing-uml-class-diagrams.html | The fastest way of drawing UML class diagrams | Java Code Geeks
http://www.javacodegeeks.com/2014/10/neo4j-collecting-multiple-values.html | Neo4j: COLLECTing multiple values | Java Code Geeks
http://www.javacodegeeks.com/2014/10/neo4j-genericvague-relationship-names.html | Neo4j: Generic/Vague relationship names | Java Code Geeks
http://www.javacodegeeks.com/2014/10/kafka-benchmark-on-chronicle-queue.html | Kafka Benchmark on Chronicle Queue | Java Code Geeks
http://www.javacodegeeks.com/2014/10/trace-output-with-drools.html | Trace output with Drools | Java Code Geeks
http://www.javacodegeeks.com/2014/10/logical-vs-physical-clock-optimistic-locking.html | Logical vs physical clock optimistic locking | Java Code Geeks
http://www.javacodegeeks.com/2014/10/jpa-tutorial-mapping-entities-part-2.html | JPA Tutorial: Mapping Entities – Part 2 | Java Code Geeks
http://www.javacodegeeks.com/2014/10/jar-hell-made-easy-demystifying-the-classpath-with-jhades.html | Jar Hell made Easy - Demystifying the classpath with jHades | Java Code Geeks
http://www.javacodegeeks.com/2014/10/di-containers-are-code-polluters.html | DI Containers are Code Polluters | Java Code Geeks
http://www.javacodegeeks.com/2014/10/the-future-is-micro-service-architectures-on-apache-karaf.html | The future is Micro Service Architectures on Apache Karaf | Java Code Geeks
http://www.javacodegeeks.com/2014/10/stateless-spring-security-part-1-stateless-csrf-protection.html | Stateless Spring Security Part 1: Stateless CSRF protection | Java Code Geeks
http://www.javacodegeeks.com/2014/10/maven-excludes-all-transitive-dependencies.html | Maven excludes all transitive dependencies | Java Code Geeks
http://www.javacodegeeks.com/2014/10/conceptual-model-vs-graph-model.html | Conceptual Model vs Graph Model | Java Code Geeks
http://www.javacodegeeks.com/2014/10/getting-started-with-docker.html | Getting Started with Docker | Java Code Geeks
http://www.javacodegeeks.com/2014/10/factory-without-if-else.html | Factory Without IF-ELSE | Java Code Geeks
http://www.javacodegeeks.com/2014/10/injecting-domain-objects-instead-of-infrastructure-components.html | Injecting domain objects instead of infrastructure components | Java Code Geeks
http://www.javacodegeeks.com/2014/10/java-and-the-sweet-science.html | Java And The Sweet Science | Java Code Geeks
http://www.javacodegeeks.com/2014/10/jpa-tutorial-mapping-entities-part-3.html | JPA Tutorial: Mapping Entities – Part 3 | Java Code Geeks
http://www.javacodegeeks.com/2014/10/what-does-a-software-architect-do.html | What Does a Software Architect Do? | Java Code Geeks
http://www.javacodegeeks.com/2014/10/java-9-behind-the-scenes-where-do-new-features-come-from.html | Java 9 Behind the Scenes: Where Do New Features Come From? | Java Code Geeks



Tuesday, October 14, 2014

Java Tech Blogs

I'll list some of the ones I'm reading, via RSS:
Blog aggregators:
Blogs:
Websites:

http://www.mkyong.com/featured/top-20-java-websites/


Monday, October 13, 2014

MySql Date Function Issues

The format of a DATE value is 'YYYY-MM-DD'. According to standard SQL, no other format is permitted. You should use this format in UPDATE expressions and in the WHERE clause of SELECT statements. For example:
SELECT * FROM t1 WHERE date >= '2003-05-05';



http://dev.mysql.com/doc/refman/5.0/en/using-date.html


Some interview Preparation Guide



http://www.quora.com/What-should-I-do-in-the-next-6-months-to-get-into-a-company-like-Amazon-Google
http://www.quora.com/Career-Cup-or-GeeksforGeeks


http://www.quora.com/What-types-of-technical-questions-are-asked-in-developer-interviews/answer/Sachin-Gupta-6

Technical Interviews generally occur at 3 different levels.
  1. When you are just out of college (Under grad), at that time its very rare that you are selected for any particular team. Sometimes even the role is not specified while you are being interviewed. However that can be negotiated after you have been selected in the interviews. In such interviews the focus is mostly on generic algorithmic questions. The aim is to test your problem solving aptitude
  2. When you have some year work or you are passing out of masters then you are generally recruited for a particular team/role in the organization. In these interviews there is a mix of algorithmic and your expertise specific questions.
  3. The third level is when you have worked in the industry for the last 8-9 years. There your experience and your resume speaks more than any technical interview that you give. There the questions generally asked for to find out how well you would gel in with the company's work culture.
As I am just out of college and have been selected in Google through my campus interviews I am best suited to discuss about the first category.

Most of the selection process has two levels. A written round and a set of one-to-one interviews.

Written round also has two further parts. One is objective questions and the other is programming questions. The objective questions may be as 
  1. Give the programming paradigm used to solve the Travelling Salesman Problem.
  2. Give the worst case complexity of Kruskal's Minimum Spanning Tree.
  3. Which protocol would you use for Live Video Streaming.
The programming questions asked in the written test are generally on the tougher side because while attempting them you have both sufficient time and working space to iterate over the solution. Questions asked maybe of type
  1. A list of strings is given. Find the number of non-anagramic strings in the list i.e. the number of strings which do not have any anagram int the list.
  2. Consider that you have 2 strings S1 and S2. You have to implement {S1 minus S2} operation, that is remove the characters present in S2 from S1. Eg S1="abcdB" and S2="b" and result would be S1="acdB". the operation has to be in-place, that is within S1 only
  3. You are given a binary tree. A term diameter is defined as the length of the longest path between  leaf nodes. Also diameter of a node is greater than/equal to:
     
    1) Diameter of left sub tree
    2) Diameter of right sub tree
    3) Length of longest path passing through the node.

    Write a program to find the diameter of the binary tree

The second is the multiple sets of personal interviews. The questions asked in them may vary over a large range of topics. One type of categorization that can be done is
  1. Programming Questions
  2. Testing Questions
  3. Design Questions

Example of Programming questions are
  • Number of occurrences of a number in a sorted array.
  • Find the intervals from a set of intervals in which a given point lies
  • Convert a doubly linked list to a Binary Search Tree

Some examples of Testing questions are 
  • Test cases for overlap of rectangles
  • Write test cases to test the functioning of a code that reverses singly linked lists.
  • How to test a program that outputs factorial of a number?

Examples of Design questions are

After this broad level of categorization you can further divide the questions into categories depending on their topics. It can be 

There are two types of problems. Generic ones and algorithm dependent.

The former consists of problems based on string manipulation, arrays, linked list etc. In such problems the focus is on covering all the cases that may occur. For example you are asked to reverse a portion of an array beginning from a particular index and ending at a particular index, then you must be thorough in covering all the cases that may occur. Solving these kinds of problems is easier if you have done sufficient practice. 

The other kind of questions are dependent on a particular algorithm or coding trick and sometimes it becomes very difficult to solve them if you have not read about them earlier. For example 
Also I have shared my experience of sitting in the campus interviews, and I would strongly suggest you to read it http://www.mycareerstack.com/blo...

Please note that in no way what I am have written above is an exhaustive description of technical interviews. Each company has its own pattern of interview questions and it may vary significantly. 

Note: All the questions posted above have occurred in some or the other technical interviews of companies like Google, Microsoft, Amazon

http://randomrants.quora.com/Hacking-the-Programming-Interview-1

http://www.quora.com/What-are-the-ways-to-utilize-6-months-to-build-skill-set-to-get-hired-at-Facebook-or-Google

http://www.quora.com/How-can-I-prepare-for-interviews-in-any-big-software-company-like-Google-Facebook-Amazon-Microsoft-DE-Shaw-Salesforce-Flipkart-Expedia-Morgan-Stanley-Goldman-Sachs-Adobe-eBay-Walmart-LinkedIn-etc/answer/Ayush-Jain-62?srid=Xymv&share=1

http://learn.hackerearth.com/questions/?type=Trees+and+Graphs