IT Knowledge Sharing | Interview questions

Solution: retainAll method do this.   public boolean retainAll (Collection<?> c) Example: public class Test {        public static void main(String [] args){          LinkedHashSet hs = new LinkedHashSet();           // add elements to the hash set           hs.add("B");           hs.add("A");           hs.add("D");           hs.add("E");           hs.add("C");           hs.add("F");           System.out.println(hs);                     LinkedHashSet hs2 = new LinkedHashSet();       ...

Find the Nth highest salary Solution: Common logic for all database is as... select t.name,t.salary from employee t   where N= (               select count(u.salary) from                   (select distinct salary from employee ) as u                   where t.salary<= u.salary        )

Errror: org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role....... Solution: Add lazy=false in your hbm file where you have declare collection... Example: <set name="hhResume" inverse="true" lazy="false" >             <key>                 <column name="UID" not-null="true" />             </key>             <one-to-many class="com.example.HhCandidate" />         </set>

Here is a code template..... public static String readGZFile(String url) throws IOException {            StringBuffer dataBuffer =new StringBuffer();            InputStream gzipStream = new GZIPInputStream((new URL(url)).openStream());            Reader decoder = new InputStreamReader(gzipStream, "UTF-8");            BufferedReader buffered = new BufferedReader(decoder);            int i=0;            String line=buffered.readLine();            while(line !=null){                dataBuffer.append(line);                line=buffered.readLine();           ...

See the code ************************************************************************************* package com.lin.web.servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.List; import java.util.logging.Logger; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.google.api.ads.common.lib.exception.ValidationException; import com.google.api.ads.dfp.appengine.oauth.CredentialException; import com.google.api.ads.dfp.jaxws.factory.DfpServices; import com.google.api.ads.dfp.jaxws.v201302.ApiException_Exception; import com.google.api.ads.dfp.jaxws.v201302.Network; import com.google.api.ads.dfp.jaxws.v201302.NetworkServiceInterface; import com.google.api.ads.dfp.lib.client.DfpSession; import com.lin.web.util.ClientLoginAuth; import com.lin.web.util.LinMobiileProperties; import com.lin.web.util.Lin...

Google Ads Developer Blog: Google App Engine for Java meet DFP API, Part 1: H... : We are excited to start discussing how to use the DFP API from within the Google App Engine (Java) environment. This first blog post in th...

Creating  custom date using java 1) Using java.util.Date  int year=2013; int month=5;   // months starts from 0 to 11, as 0 stands January and 11 stands for December int day=15; int hour=12; int minute=58; int seconds=47; *** Date utilDateObj=new Date(year,month,day,hour,minute,seconds); ***  This is depricated. We recommend to use Calander as given below: Calendar calendar = Calendar.getInstance(); calendar.clear(); calendar.set(Calendar.YEAR, year); calendar.set(Calendar.MONTH, month); calendar.set(Calendar.DAY_OF_MONTH, day); calendar.set(Calendar.HOUR, hour); calendar.set(Calendar.MINUTE, minute); calendar.set(Calendar.SECOND, seconds); Date lastUpdatedDate = calendar.getTime();