Tag Archives: Maven

[Solved] java.nio.file.NoSuchFileException: XYZ


NoSuchFileException occurred when trying to attempt access a file or directory which is not exist in given location.

NoSuchFileException is sub class of FileSystemException. This exception  introduced in Java 7.

Example for NoSuchFileException

This example is throwing NoSuchFileException because trying to access a file student_data.json which is not exist on default location.

package com.fiot.json.jackson;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.List;

import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fiot.json.jackson.pojo.Student;

public class ConvertJsonToArrayList {

	public static void main(String[] args) {
		try
		{
		byte[] mapData = Files.readAllBytes(Paths.get("student_data.json"));
		Student[] studentArr = null;

		ObjectMapper objectMapper = new ObjectMapper();
		studentArr = objectMapper.readValue(mapData, Student[].class);
		List studentList=Arrays.asList(studentArr);
		System.out.println("Student 1 \n"+studentList.get(0));
		System.out.println("Student 2 \n"+studentList.get(1));

		}
		catch(JsonMappingException ex)
		{
			ex.printStackTrace();
		}
		catch(IOException ex)
		{
			ex.printStackTrace();
		}

	}

}

Exception Stacktrace


java.nio.file.NoSuchFileException: student_data.json
    at sun.nio.fs.WindowsException.translateToIOException(Unknown Source)
    at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
    at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
    at sun.nio.fs.WindowsFileSystemProvider.newByteChannel(Unknown Source)
    at java.nio.file.Files.newByteChannel(Unknown Source)
    at java.nio.file.Files.newByteChannel(Unknown Source)
    at java.nio.file.Files.readAllBytes(Unknown Source)
    at com.fiot.json.jackson.ConvertJsonToArrayList.main(ConvertJsonToArrayList.java:18)

Solutions

There are couple of solutions to handle such situations:

  1. Use fully qualified file path such as “C:/data/student_data.json” but that will help only when your program is going to run on local machine. While working with enterprise application always use relative paths.
  2. If your file in source directory use path as “src/student_data.json”
  3. If your project is maven project, always write script to copy file which you want to access or keep in resource folder to access because maven project create different directory structure after build.

Solution depend on your project requirement. You can use below code to get qualified full path of a file

public static void main(String [] args) {

    String filename="student_data.json";
    //To get path of file
    Path path = Paths.get(filename);
    //To print absolute path of file
    System.out.println(path.getAbsolutePath());

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[Solved] Could not transfer artifact org.springframework:XYZ from/to central (https://repo.maven.apache.org/maven2)


Generally this error message shows in pom.xml when create new project with dependencies or add new dependencies in pom.xml.

Reason to cause this error

There are several reason to cause this error as below because maven is unable to connect to Maven repository at http://repo1.maven.org/maven2.

  1. Proxy
  2. Network issue
  3. .lastUpdate file for dependency

Could not transfer artifact org.springframework:spring-expression:jar:5.1.6.RELEASE from/to central (https://repo.maven.apache.org/maven2): C:\Users\saurabh.gupta1\.m2\repository\org
 \springframework\spring-expression\5.1.6.RELEASE\aether-fa07bf3e-4fa1-4911-bcad-3319e4b2480e-spring-expression-5.1.6.RELEASE.jar-in-progress (The system cannot find the file 
 specified) org.eclipse.aether.transfer.ArtifactTransferException:
 

Solutions

There are few ways i find out to resolve this issue:

Maven Force Update of Snapshot/Releases

Follow below steps to to resolve this issue and clear all dependencies error in eclipse.

  1. Right click on project.
  2. Go to Maven
  3. Update project , the check the above option “Force update of Snapshot/Releases“.
  4. Click on Ok.
  5. If not fixed restart your eclipse.

Maven Force Update 1

Maven Force Update 2

Maven access through Proxy

Update your proxy configuration in maven settings.xml file and put it inside .m2 folder

C:\Users\USER NAME.m2

proxy settings


<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0                               
http://maven.apache.org/xsd/settings-1.0.0.xsd">

 <proxies>
    <proxy>
      <id>myproxy</id>
      <active>true</active>
      <protocol>http</protocol>
      <username>user name</username>  <!-- Put your user name here -->
      <password>password</password>   <!-- Put your password here -->
      <host>127.56.8.64</host>        <!-- Put the IP address of your proxy server here -->
      <port>80</port>                 <!-- Put your proxy server's port number here -->
      <nonProxyHosts>local.net|some.host.com</nonProxyHosts> <!-- Do not touch this setting unless you know what you're doing. -->
    </proxy>  
  </proxies>
</settings>

You don’t need to touch , and sections, unless you really know what are these tags.

After updating this setting restart eclipse and follow the steps in Maven Force update of Snapshot/Releases.

Remove .lastUpdated file

If this problem is not resolved yet got to .m2/repository/ to dependency sub directory and remove .lastUpdate file inside of it or delete complete directory for this particular dependency and again follow the steps in Maven Force update of Snapshot/Releases.

For Example as for above issue directory location showing in exception as

C:\Users\saurabh.gupta1.m2\repository\org
\springframework\spring-expression\5.1.6.RELEASE

Above solutions are my research to resolve this issue if you find out or know other ways please suggest in comments.

Elasticsearch REST JAVA API


Elasticsearch 5 provides low level client api’s to communicate with Elasticsearch Cluster over HTTP by JAVA. Because of REST services and JSON able to communicate with all version of Elasticseach and across firewall also.

Elasticsearch REST Client sent http requests internally by using Apache Http Async Client.

In case of version change on Elasticsearch Cluster no need to change for client and will not impact any communication.

Initial Release Version : 5.0.0-alpha4

Elasticsearch REST Features

  • Keep connection persistent.
  • Logged request and response by Elasticsearch Rest API.
  • Load balancing across all available nodes.
  • Failover incase of node fail and upon specific response codes.
  • Provide sniffing to discovery of clusters node.
  • Minimum Dependencies.

Pre-Requisite

Elasticsearch Rest required minimum Java version is 1.7

Elasticsearch REST Java API Configuration

 Maven Configuration

Add below dependency in pom.xml file to import all library.

.<dependency>
      <groupId>org.elasticsearch.client</groupId>
      <artifactId>rest</artifactId>
      <version>5.1.2</version>
</dependency>

Gradle Configuration

Add below dependency in build.gradle file to import all library.

dependencies {   compile 'org.elasticsearch.client:rest:5.1.2'}

Read More on Elasticsearch REST

Integration

Integrate Filebeat, Kafka, Logstash, Elasticsearch and Kibana