Insertion Sort Example program in JAVA


package in.malliktalksjava;

/**
* @author malliktalksjava
* This class sort an array using Insertion sort algorithm.
*
*/
public class InsertionSortExample {

/**
* @param args
*/
public static void main(String args[]){
int[] arr1 = {10,34,2,56,7,67,88,42};
int[] arr2 = doInsertionSort(arr1);
for(int counts:arr2){
System.out.print(counts);
System.out.print(“, “);
}
}

/**
* @param input
* @return
*/
/**
* @param input
* @return
*/
public static int[] doInsertionSort(int[] input){

int temp;
for (int count = 1; count < input.length; count++) {
for(int count2 = count ; count2 > 0 ; count2–){
if(input[count2] < input[count2-1]){
temp = input[count2];
input[count2] = input[count2-1];
input[count2-1] = temp;
}
}
}
return input;
}
}

 

Other Useful Links:

Selection Sort Example Program in JAVA

Bubble Sort Example in JAVA

Quick Sort Example Program in Java

Merge Sort Example in Java

Selection Sort Example Program in Java


package in.malliktalksjava;

/**
* @author malliktalksjava
* @version 1.0
*
* Below class sorts the given array using SelectionSort
* mechanism and prints the output into console.
*/
public class SelectionSortExample {

/**
* @param args
*/
public static void main(String args[]){

int[] arr1 = {12,434,2,23,7,44,66,42};
int[] arr2 = doSelectionSort(arr1);
for(int var:arr2){
System.out.print(var);
System.out.print(“, “);
}
}

/**
* @param arr
* @return sorted array
*/
public static int[] doSelectionSort(int[] arr){

for (int count = 0; count < arr.length – 1; count++)
{
int index = count;
for (int count2 = count + 1; count2 < arr.length; count2++){
if (arr[count2] < arr[index]){
index = count2;
}
}

int smallerNumber = arr[index];
arr[index] = arr[count];
arr[count] = smallerNumber;
}
return arr;
}
}

 

Other Useful Links:

Bubble Sort Example in JAVA

Insertion Sort Example program in JAVA

Quick Sort Example Program in Java

Merge Sort Example in Java

Bubble Sort Example in JAVA


package in.malliktalksjava;

/**
* @author malliktalksjava
*
*/
public class BubbleSortExample {

private static int[] input = { 4, 2, 9, 6, 23, 11, 44, 0 };

public static void bubbleSort(int arr[]) {
 int count = array.length;
 int var;
 for (int i = count; i >= 0; i--) {
   for (int j = 0; j  array[j+1]) {
          swapNumbers(temp2, var, array);
      }
   }
 printNumbers(array);
 }
}

private static void swapNumbers(int var1, int var2, int[] array) {
   int temp = array[var1];
   array[var1] = array[var2];
   array[var2] = temp;
}

private static void printNumbers(int[] input) {
  for (int i = 0; i < input.length; i++) {
    System.out.println(input[i] + ", ");
  }
}
}

Other Useful Links:

Selection Sort Example Program in JAVA

Insertion Sort Example program in JAVA

Quick Sort Example Program in Java

Merge Sort Example in Java

Number series example program using JAVA


package in.malliktalksjava;

/**
* @author malliktalksjava.in
*
* This program prints the numbers in below pattern
* 1
* 123
* 12345
* 1234567
* 12345
* 123
* 1
*/
class PrintingNumberPatterns{

public static void main(String[] args){
printNumberSeries();
}

/**
* Print the numbers in assending and decending order by iterating it.
*/
private static void printNumberSeries() {
for (int i = 1; i <= 7; i += 2) {
for (int j = 1; j <= i; j++) {
System.out.print(j);
}
System.out.println();
}

for (int i = 5; i >= 1; i -= 2) {
for (int j = 1; j < i + 1; j++) {
System.out.print(j);
}
System.out.println();
}
}
}

javax.servlet.ServletException: BeanUtils.populate


javax.servlet.ServletException: BeanUtils.populate
org.apache.struts.util.RequestUtils.populate(RequestUtils.java:497)
org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:798)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:205)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

Root Cause:

java.lang.IllegalArgumentException: argument type mismatch
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:585)
org.apache.commons.beanutils.PropertyUtils.setSimpleProperty(PropertyUtils.java:1789)
org.apache.commons.beanutils.PropertyUtils.setNestedProperty(PropertyUtils.java:1684)
org.apache.commons.beanutils.PropertyUtils.setProperty(PropertyUtils.java:1713)
org.apache.commons.beanutils.BeanUtils.setProperty(BeanUtils.java:1019)
org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:808)
org.apache.struts.util.RequestUtils.populate(RequestUtils.java:495)
org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:798)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:205)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

Solution:

Fallowings are may be the reason for the above exception
1) The action attribute of an tag must match exactly the path attribute of the action definition in the struts-config.xml file. This is how Struts associates the ActionForm bean with the action.

2) This error usually occurs when you have specified a form name that does not exist in your tag. For example, you specific and ‘myForm’ is not the name of a form associated with myAction in the struts-config file

3) You get this message when Struts is unable to map the data in the HTML form to the properties in your ActionForm bean. Make sure each of the properties on your bean is either a String or a Boolean. Do you have any properties of type java.util.Date or other objects? That might cause this error. Also check to see that you have public getters and setter for each of your properties.

org.hibernate.exception.ConstraintViolationException


org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:69) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:202)at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:91)at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:86)at org.hibernate.jdbc.AbstractBatcher.prepareBatchStatement(AbstractBatcher.java:171)at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2048)at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2427)at org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:51)at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:243)at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:227)at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:140)at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:296)at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:980)at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:353)at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)at struts.dao.project.budgetAnalysis.BudgetPlanningDAO.saveNewBudget(BudgetAnalysisDAO.java:428)at struts.project.budgetAnalysis.NewBudgetPlanSaveAction.execute(NewBudgetSaveAction.java:99)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:595)
Caused by: java.sql.BatchUpdateException: ORA-01400: cannot insert NULL into ("ROOT"."PROJECT_BUDGET_TEST"."APPROVED_STATUS")

at oracle.jdbc.driver.DatabaseError.throwBatchUpdateException(DatabaseError.java:367)
at oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:8739)
at org.apache.tomcat.dbcp.dbcp.DelegatingStatement.executeBatch(DelegatingStatement.java:294)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:58)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:195)
... 36 more

Solution:

This type of problems generally occurs when we try to violate the constraint relationship of the tables.
The fallowing cases may be the reason for the above exception:
1)If the user try to enter null value into not null fields of the database.
2)If the user trying to store other format value into the database field.

org.hibernate.TransientObjectException


org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before
flushing: hibernate.hr.employee.EmployeeStoreValue
at org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:216)
at org.hibernate.type.EntityType.getIdentifier(EntityType.java:108)
at org.hibernate.type.ManyToOneType.nullSafeSet(ManyToOneType.java:71)
at org.hibernate.persister.entity.AbstractEntityPersister.dehydrate(AbstractEntityPersister.java:1826)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2172)
at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2118)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2374)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:84)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:243)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:227)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:141)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:296)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:980)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:353)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
at struts.dao.project.budgetAnalysis.BudgetAnalysisDAO.updateProjectBudget(BudgetDAO.java:574)
at struts.project.budgetAnalysis.BudgetPlanningAction.approveRejectBudgetExecute(BudgetStoringgAction.java:480)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:276)
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:196)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:421)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:226)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:595)

Solution:

This type of Exception do you get generally when you try to store a null object in to the database column which has foreign key relationship with the other table column. Even if you are trying to store other column value which is not a primary key column.

Basic MQ Commands


1. Create/start/stop a Queue Manager

crtmqm [-z] [-q] [-c Text] [-d DefXmitQ] [-h MaxHandles]
[-g ApplicationGroup] [-t TrigInt]
[-u DeadQ] [-x MaxUMsgs] [-lp LogPri] [-ls LogSec]
[-lc | -ll] [-lf LogFileSize] [-ld LogPath] QMgrName

Output :

WebSphere MQ queue manager created.
Creating or replacing default objects for QMA.
Default objects statistics : 43 created. 0 replaced. 0 failed.
Completing setup.
Setup completed.

2. Starting a Queue Manager

$ strmqm QMA

Output:

WebSphere MQ queue manager ‘QMA’ starting.
2108 log records accessed on queue manager ‘QMA’ during the log
replay phase.
Log replay for queue manager ‘QMA’ complete.
Transaction manager state recovered for queue manager ‘QMA’.
WebSphere MQ queue manager ‘QMA’ started.

3. Checking that the Queue Manager is running

$ dspmq

Output :

QMNAME(QMA) STATUS(Running)

4. Stopping a Queue Manager

$ endmqm –i QMA

5. Deleting a Queue Manager

The following command will stop all the Listeners associated with Queue Manager pointed to by the –m flag (QMA in this example). The –w flag means the command will wait until all the Listeners are stopped before returning control:

$ endmqlsr -w -m QMA

The command to stop (end) the Queue Manager is:

$ endmqm QMA

And fnally the command to delete the Queue Manager is:

$ dltmqm QMA

 

Other Useful Links:

Enable JMX Remote port in WebSphere

 

Install SSL Certificates into Java JRE


Some times it would require to install the SSL certificates into our JRE. Below are the steps that need to perform to get the certificates added into the JRE security folder.

1. Navigate to JDK\jre\bin and copy the “keytool.exe” and “jli.dll” files to the JDK\jre\lib\security directory.

2. Copy the your XXX.cer files to the JDK\jre7\lib\security directory

3. Open command prompt and navigate to the JDK\jre\lib\security directory

4. Run the following command to verify the tool is working: “keytool -list -keystore cacerts”

a. Default password to access the keystore is: changeit

5. Run the following commands to import the certificates

     keytool -keystore cacerts -importcert -alias YYY -file XXX.cer

6. If the certificate already exists then there is no need to re-import it.

 

Other Useful Links:

Javac/Java searching algorithm for other classes

Struts Internationalization Example

How to find count of duplicates in a List

How to Create a Thread Using Runnable Interface

Javac/Java searching algorithm for other classes


With this post, I would like to explain how exactly the Java/Java will search for its dependencies in the project or application level. Java Applications can be run using the command line or in the Web/Application servers. For both the scenarios will be covered as below:

When you are accessing standalone application using command prompt, below will be the search criteria steps:

Step 1: The first place that look in the directories that contains the classes that come with Java SE.

Step 2: The classpath that declared as command line options for either Java/Javac. Since the classpath declared in command line options override the classpath declared in command line options persists only for the length of the invocation.

Step 3: Looks for the the default classpath that declared as System Environment Variables.

When you are accessing the application from Web or application servers, below will be the search criteria steps:

Step 1: The first place that look in the directories that contains the classes that come with Java SE.

Step 2: If the dependencies not able to identify in the JRE lib folder, then it will be looked into the Application lib folder.

Step 3: If the dependencies not able to fine in above two steps, then it will be looked into Web/App server lib folder.

 

Other Useful Links:

Differences between Object and Instance
Difference between Abstract Class and Interface:
Threads Interview questions in Java
Access Specifiers in Java
Avoid nested loops using Collection Framework in Java