Tag Archives: environment

[Solved] Maven: No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK

This maven exception occurs  when your Window/Unix environment variable for JAVA_HOME and PATH are pointing to JRE instead of JDK. That’s why maven will not compile code and throw below exception.


[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building SpringBootApp 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-install-plugin/2.5.2/maven-install-plugin-2.5.2.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-install-plugin/2.5.2/maven-install-plugin-2.5.2.pom (7 KB at 2.3 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/25/maven-plugins-25.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/25/maven-plugins-25.pom (10 KB at 10.2 KB/sec)
[INFO] --- maven-resources-plugin:3.0.1:resources (default-resources) @ SpringBootApp ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 0 resource
[INFO] Copying 0 resource
[INFO] --- maven-compiler-plugin:3.7.0:compile (default-compile) @ SpringBootApp ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to D:\Saurabh Gupta\facingIssuesOnIT\SpringBootApp\target\classes
[INFO] -------------------------------------------------------------
[INFO] -------------------------------------------------------------
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5.342 s
[INFO] Finished at: 2018-05-28T15:59:31+05:30
[INFO] Final Memory: 20M/209M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:compile (default-compile) on project SpringBootApp: Compilation failure
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[ERROR] -> [Help 1]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException


To resolve this issue you can follow below steps by solving command prompt or Eclipse.

Command Prompt

How to Configure Maven in Window and Linux?


  • Right click on project -> Select Properties
  • Select Java Build Path-> Libraries Tab -> Click on Add Library
  • Refer below link for reference.

Eclipse : How to set java path of JDK/JRE?

How to Sort By Comparable Interface in Ascending and Descending Order : Java

As in previous post shown like wrapper of primitive type , String and Date classes having  implements in-built comparable interface which provide natural or chronological or alphabetical sorting of elements.

Sort ArrayList in Ascending or Descending Order or Natural or Chronological Order

How to sort object by Comparator interface in ascending and descending order : JAVA

Java : Comparable Vs Comparator

What is Comparable Interface?

java.lang.Comparable  interface imposes a total natural ordering on the objects of each class that implements it.  it provide compareTo() method which compares the receiving object with the specified object and returns a negative integer, 0, or a positive integer depending on whether the receiving object is less than, equal to, or greater than the specified object. If the specified object cannot be compared to the receiving object, the method throws a ClassCastException.

How to use Comparable Interface?

Below is syntax of compareTo method:

public interface Comparable {
    public int compareTo(T o);


compareTo() method compare current object (this)  fields values with passing object fields values and return negative integer, 0 or a positive integer and Collections.sort() method will sort based on this return value.

Lists (and arrays) of objects that implement this comparable interface can be sorted automatically by Collections.sort (and Arrays.sort). Objects that implement this comparable interface can be used as keys in a sorted map or as elements in a sorted set, without the need to specify a comparator.

Example :

Below Employee class implements compareTo() method of  java.lang.Comparable  interface which is comparing firstName value with specified object firstName value. This  method return a integer value like (negative integer, 0 or positive integer) depend on compare result.

package sorting;

public class Employee implements Comparable{
private int id;
private String firtsName;
private String lastName;
private String designation;
private double salary;
private int age;

//Default Constructor
public Employee()


//Parametrize Constructor
public Employee(int id, String firtsName, String lastName, String designation, double salary, int age) {
	this.id = id;
	this.firtsName = firtsName;
	this.lastName = lastName;
	this.designation = designation;
	this.salary = salary;
	this.age = age;

public int compareTo(Employee employee) {
	//sort by firstName
	return this.firtsName.compareTo(employee.firtsName);

public int getId() {
	return id;
public void setId(int id) {
	this.id = id;
public String getFirtsName() {
	return firtsName;
public void setFirtsName(String firtsName) {
	this.firtsName = firtsName;
public String getLastName() {
	return lastName;
public void setLastName(String lastName) {
	this.lastName = lastName;
public String getDesignation() {
	return designation;
public void setDesignation(String designation) {
	this.designation = designation;
public double getSalary() {
	return salary;
public void setSalary(double salary) {
	this.salary = salary;
public int getAge() {
	return age;
public void setAge(int age) {
	this.age = age;

@Override<span id="mce_SELREST_start" style="overflow:hidden;line-height:0;"></span>
public String toString() {
	return "Employee [id=" + id + ", firtsName=" + firtsName + ", lastName=" + lastName + ", designation=" + designation
			+ ", salary=" + salary + ", age=" + age + "]";


In below class sorting  Employee list objects by names in ascending order by Collections.sort(list). As shown above Employee Class implements  Comparable interface and it’s  compareTo() method  will sort elements in Ascending order by firstName on objects.

For Descending order used Collections.reverse(List) reverse method which will reverse list of sorted list.


package sorting;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class SortComparable {

	public static void main(String[] args) {
		Employee [] empArr={
				new Employee(1,"Saurabh","Gupta","Sr Project Lead",60000,35),
				new Employee(2,"Gaurav","Gupta","Developer",50000,32),
				new Employee(3,"Shailesh","Nagar","Manager",100000,36),
				new Employee(4,"Ankur","Mehrotra","Lead",55000,30),
				new Employee(5,"Ranjith","Ranjan","Tester",35000,45),
				new Employee(6,"Ramesh","Bhardwaj","Support",25000,35)
		//Convert Array to LIst
		List empList=Arrays.asList(empArr);
		//Print Assigned Values Before Sort;
		System.out.println("********Print Employee List Before Sort********");

		//Sort List in Ascending order by collections api
		System.out.println("\n********Print Employee List in Ascending Order********");

		//Sort List in Descending order by collections api
		System.out.println("\n********Print Employee List in Descending Order********");


	private static void printArrayList(List empList)
		for(Employee emp:empList)


Reference :


[Solved] ArrayIndexOutOfBoundException in JAVA

java.lang.ArrayindexOutOfboundsException is Runtime and Unchecked Exception. It’s subclass of java.lang IndexOutOfBoundsException.

ArrayIndexOutOfBoundsException is most common error in Java Program. It throws when an array has been accessed with an illegal index either negative or greater than or equal to the size of the array.

Points To Remember:

  •  Array index starts at zero and goes to length – 1, for example in an integer array int[] counts= new int[20], the first index would be zero and last index out be 19 (20 -1)
  • Array index cannot be negative, hence counts[-1] will throw java.lang.ArrayIndexOutOfBoundsException.
  • The maximum array index can be Integer.MAX_VALUE -1 because array accept data type of index is int and max allowed value for int is Integer.MAX_VALUE.


  • ArrayIndexOutOfBoundsException() : Constructs an  ArrayIndexOutOfBoundsException with no detail message.
  • ArrayIndexOutOfBoundsException(int index) : Constructs a new ArrayIndexOutOfBoundsException class with an argument indicating the illegal index.
  • ArrayIndexOutOfBoundsException(String s) : Constructs an ArrayIndexOutOfBoundsException class with the specified detail message.

Example :

public class ArrayOutOfBoundException {

	public static void main(String[] args) {
		String [] empArr={"Saurabh","Gaurav","Shailesh","Ankur","Ranjith","Ramesh"};
		//No of employee in array
		//Will through IndexOuhtOfBoundException because array having only six element of index 0 to 5
		String name=empArr[8];
		System.out.println("Employee :"+empArr[8]);
		catch(ArrayIndexOutOfBoundsException ex)


java.lang.ArrayIndexOutOfBoundsException: 8
	at example.ArrayIndexOutOfBoundsException.main(ArrayIndexOutOfBoundsException.java:11)<span id="mce_SELREST_start" style="overflow:hidden;line-height:0;"></span>

Filebeat, Commandline Arguments Configuration

Environment and Commandline arguments setting to filebeat.yml

We can use environment variables and arguments from command line  references in the filebeat.yml file to set values or fields that need to be configurable during deployment. To configure fields and values use like this:


Where VAR1 is the name of the environment variable or passing values from command line.

These configured values will replaced on start up by the value of environment variable or command line arguments. These configured fields are case sensitive if value not found will fail on parsing so better configure values with default value as given below.


We pass command line arguments to set configured values with option -E with argument name.

We have configured in below file variable fields for server, kafkaHost and topic in below sample configuration file that way we can set other fields also as per requirement.

Use below command to run this sample configuration file:

./filebeat -c filebeat.yml -d publish -E server=server1 -E kafkaHost=IP:PORT -E topicName=QC-TEST

For example above commandline arguments will pass to filebeat.yml file for below settings.

Prospectors Settings :

- input_type: log
- /opt/app/${server}/logs/app1-debug*.log*
fields_under_root: true

Kafka Output Settings:

#enabled: true
hosts: ["${kafkaHost}"]
topic: ${topicName}


Complete Integration Example Filebeat, Kafka, Logstash, Elasticsearch and Kibana

Read More

To read more on Filebeat topics, sample configuration files and integration with other systems with example follow link Filebeat Tutorial  and  Filebeat Issues.To Know more about YAML follow link YAML Tutorials.

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