STS : Spring Roo Project Creation Gives Error mojo codehaus

Those who started working with Spring-Roo for faster development but facing difficult to set up STS Spring Roo Project Environment.

It may turn to roadblock if below problems cannot be resolved:

• Code is not compilable.
• Maven Dependencies are not shown in project configurations.
  

This is having 3 fixes & you can start your development:

• Update POM file for correct aspect version : 1.9 for JDK 1.8 onwards
• <aspectj.plugin.version>1.9</aspectj.plugin.version>
  
  
• Configure correct location for maven settings.xml 
• By default it will search in %USER_PROFILE%\.me\settings.xml
• So set to MVN 3.5+ : %MAVEN_HOME%\conf\settings.xml
  
  
• Maven Profile must be "development"
• Follow Below instructions for Maven profile update:

accepted

You can activate the maven profile at the Eclipse by using the following step: - Right click at your project and select properties . At the Properties windows select Maven. At the right hand panel you will see Active Maven Profiles text box. Please enter your profile name, e.g. development or production.

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Thanks & Regards,
Abhijeet

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[Performance] java Map.containsKey() redundant when using map.get()

In most of our code, we generally use HashMap.

 

Most of the operation we do:

·         Prepare HashMap to process.

·         Process the HashMap.

·         Retrieve data from Map.

 

Following use-case needs to be avoided:

Most of the time to avoid NPE (NullPointerException) code is getting handled in below way:

 

 

dataMap.contains(key) ? dataMap.get(key) : someObject;

 

Avoid using above as it may impact performance because both below APIs do same operation:

·         containsKey()

·         get(key)

 

SO optimized code for avoiding redundant Map processing:

 

Object  mappedValue = dataMap.get(key);       // fetch only once  (mappedValue == null) ? someObject: mappedValue;

 

 

This is definitely useful for dealing bigger DataSet.

 

Also don't forget to use collection.clear(); if data is no more required.

 

 

III

Best Regards,

Abhjeet.