IT Knowledge Sharing | Interview questions

This article is all about how you configure MDC logs with SLF4J and logback. 1. Maven POM dependencies : Please add maven dependencies as given below.        <!-- Logging with SLF4J & LogBack --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.0.13</version> </dependency> 2. Configure logback.xml file <?xml version="1.0" encoding="UTF-8"?> <configuration scan="true" scanPeriod="30 seconds"> <property name="DEV_HOME" value="c:/logs" />     <contextListener class="ch.qos.logback.classic.jul.LevelChangePropagator">         <resetJUL>true</resetJUL>     </con...

You want to explore struts 1.X with ajax based application which returns JSON as a response, you can go following public repository. https://github.com/youdhveer/struts1

Suppose we have a device table along with following columns. id(integer),device(varchar),device_data(varchar). Now suppose you want to upload data from a device.csv file like given below. --------------------------------------------------- "id","device","device_data" "1","A1","this is test device, model-11" "2","A2","this is test device, model-12" "3","A3","this is test device, model-13" "4","A4","this is test device, model-14" ---------------------------------------------------- Use following command to insert these values from csv file to table with casting id value from text to integer. LOAD DATA INFILE 'D:\device.csv' INTO TABLE device  FIELDS TERMINATED BY  ','  ENCLOSED BY '"' LINES TERMINATED BY '\n' IGNORE 1 LINES (@id, device, device_data) SET id= CONVERT( @id, UNSIGNED...

Here is the function which will return string after removing duplicate text from a csv cell value. create function dbo.RemoveDuplicateTextInCSVString(@SOURCE_STR varchar(50)) returns varchar(50) as begin     declare @TEMP_STR varchar(50)   declare @WORD_STR varchar(50)   set @TEMP_STR = ','   while len(@SOURCE_STR) > 0 begin print '--------------------' set @WORD_STR = left(@SOURCE_STR, charindex(',', @SOURCE_STR+',')-1)+',' print '@WORD_STR :'+ @WORD_STR if charindex(','+@WORD_STR, @TEMP_STR) = 0 begin set @TEMP_STR = @TEMP_STR + @WORD_STR print '@TEMP_STR : '+@TEMP_STR end else print 'found duplicate, remove this..' set @SOURCE_STR = stuff(@SOURCE_STR, 1, charindex(',', @SOURCE_STR+','), '') print '@SOURCE_STR '+@SOURCE_STR   end   return @SOURCE_STR end

Value as a Reference example : Here we are fecthing a list from a collection and updating this which leads to automatic update of Map because  numList is directly referring to   testmap. ----------------------------------- public class ValueAsReference{ enum EvenOdd{ EVEN,ODD } public static void main(String ... arg){ Map<String,List<String>> testmap=new HashMap<String, List<String>>(); for(int i=0;i<20;i++){ String key=""; if(i%2 ==0){ key=""+EvenOdd.EVEN; }else{ key=""+EvenOdd.ODD; } List<String> numList=testmap.get(key); if(numList==null){ numList=new ArrayList<String>(); numList.add("i="+i); testmap.put(key, numList); }else{ numList.add("i="+i); } } for(String key : testmap.keySet()){ System.out.println("key : "+key); System.out.println(testmap.get(key)); } ...

No, there is no way to restore a deleted bucket or object inside a bucket. DELETE operation comes under strong global consistency. Keep in mind that you can use Google Cloud Storage only after enabling billing for your project. It's not free. You can go through Cloud storage documentation   Bucket will be deleted permanently. You can see google documentation.  Although a bucket will be deleted only if it is empty, means you have to delete all objects first and then you can delete an empty bucket. Choose bucket carefully as these are unique globally and can not be nested like folders or directories.

Set Context path in Tomcat 7 or more using catalina.properties file, Step 1) Add following lines to catalina.properties file under <tomcat-install dir>/conf directory, #myApp war file version myApp .war=myAppLive -1.0.0.1.war myApp .path=/myAppLive #application deployment location appBase=webapps Step 2) Now update context path in <Host> node in server.xml file in same location, <Host name="localhost"  appBase="webapps"             unpackWARs="true" autoDeploy="false"> ... ....     <Context path="${myApp .path}" docBase="${catalina.base}/${appBase}/${myApp .war}"/> ... .... </Host>