Develop Reference

How to import java project as module in java web project using intelijj?

I wanted to use the class from basic java project inside java servlet class which is defined in another project.
I tried importing project as module through the module dependency InteliJ menu.
At compile time ,it is not giving any error ,but after running the server(Glassfish) and calling the servlet it is giving below error.
java.lang.NoClassDefFoundError: com/practise/LogFileCreator at UserLoginValidator.dbConnectionMaker(UserLoginValidator.java:31)>
Please find below code which causing error.
below class is from web project
import jakarta.servlet.*;
import jakarta.servlet.http.*;
import java.io.*;
import com.practise.LogFileCreator;
public class UserLoginValidator extends HttpServlet
{
public String LogFilePath="D:\\Logs";
public PrintWriter out;
String errormsg="";
//********************
LogFileCreator l ;
#Override
public void init() throws ServletException {
try {
this.l = new LogFileCreator(LogFilePath); // here i am trying to create object of my class which causing the mentioned error.
l.WriteLog("Hello");
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
{
}
}
below class is from normal java project
package com.practise;
import java.io.*;
public class LogFileCreator
{
private String filepath;
private StringBuffer sb = new StringBuffer("Log");
private File file;
private FileWriter fileWriter;
private BufferedWriter bufferedWriter;
public PrintWriter p;
public LogFileCreator(String filepath) throws IOException
{
this.filepath=filepath;
String filename=sb.toString().concat(java.time.LocalDate.now().toString());
this.file = new File(this.filepath,filename);
this.fileWriter= new FileWriter(file,true);
if(!file.exists())
{
file.createNewFile();
}
p= new PrintWriter(fileWriter);
}
public void WriteLog(String logMessage){
p.println(java.time.LocalDateTime.now() + " : " + logMessage);
p.flush();
}
}
Here is the image for module dependency I used .
Image
Earlier I was using LogFileCreator.java class from same web project and it was working fine
Here what i am trying to acheive is ,without writing the LogFileCreator class again in web project ,wants to reuse the class written already inside normal java project to print the logs in desired text file .
Any solution/suggestions would be appreciated.
Thank you!
[Edit 1]
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>webapp</artifactId>
<version>1.0-SNAPSHOT</version>
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependencies>
<dependency>
<groupId>jakarta.servlet</groupId>
<artifactId>jakarta.servlet-api</artifactId>
<version>5.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.microsoft.sqlserver</groupId>
<artifactId>mssql-jdbc</artifactId>
<version>9.4.0.jre11</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.example</groupId>
<artifactId>Logging</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
</dependencies>
<!-- String Driver= "com.microsoft.sqlserver.jdbc.SQLServerDriver";-->
<!-- String dbusername="sa";-->
<!-- String dbpassword="Admin#123";-->
<!-- String connectionString="jdbc:sqlserver://localhost:1433;databasename=Users;";-->
<!-- -->
<properties>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
</properties>
</project>

Here What I did which resolved the above problem.
First I converted my first basic java project to maven project .
secondly I added maven dependency for the 2nd project (web project) and also added the jar file (of first project classes ) inside the web INF/lib directory of web project using below option from InteliJ .
Image

The server's classloader does not have a copy of LogFileCreator.class so the class is not on it's classpath.

It is probably how the deployment file (assuming war) was packaged. How are you building the file? Maven, Gradle, neither, etc.?
Edit
I wanted to give a bit more clarity for others who might stumble upon a similar issue. During compile time, the project/module in question was imported; however, maven does not know to package that library in the generated war. When it was deployed to Glassfish, the war did not contain the LogFileCreator class because it was not packaged in the war. The authors solution worked because maven is packaging the module into the war and Glassfish can now find the class.

Integrate New Relic with Spring Boot using Micrometer

I am trying to integrate a simple Spring Boot Application with New Relic using Micrometer.
Here are the configurations details:-
application.properties
management.endpoints.web.exposure.include=*
management.endpoint.health.show-details=always
management.metrics.export.newrelic.enabled=true
management.metrics.export.newrelic.api-key:MY_API_KEY // Have added the API key here
management.metrics.export.newrelic.account-id: MY_ACCOUNT_ID // Have added the account id here
logging.level.io.micrometer.newrelic=TRACE
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.5</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>springboot.micrometer.demo</groupId>
<artifactId>micrometer-new-relic</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>micrometer-new-relic</name>
<description>Demo project for actuator integration with new relic using micrometer</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>io.micrometer</groupId>
<artifactId>micrometer-registry-new-relic</artifactId>
</dependency>
<dependency>
<groupId>io.micrometer</groupId>
<artifactId>micrometer-registry-prometheus</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
</project>
I was able to integrate Prometheus with this application using micrometer-registry-prometheus dependency. I had set up Prometheus to run in a Docker container in my local system. I used the following set of commands-
docker pull prom/prometheus
docker run -p 9090:9090 -v D:/Workspaces/STS/server_sent_events_blog/micrometer-new-relic/prometheus.yml:/etc/prometheus/prometheus.yml prom/prometheus
prometheus.yml
global:
scrape_interval: 4s
evaluation_interval: 4s
scrape_configs:
- job_name: 'spring_micrometer'
metrics_path: '/actuator/prometheus'
scrape_interval: 5s
static_configs:
- targets: ['my_ip_address:8080']
When I navigated to localhost:9090/targets I can see that Prometheus dashboard shows my application details and that it can scrape data from it. And in the dashboard, I can see my custom metrics as well along with other metrics.
So my question is I want to achieve the same thing using New Relic. I have added the micrometer-registry-new-relic pom dependency. I have shared the application.properties file as well. I can see logs in my console saying it is sending data to New Relic-
2021-10-24 12:42:04.889 DEBUG 2672 --- [trics-publisher] i.m.n.NewRelicInsightsApiClientProvider : successfully sent 58 metrics to New Relic.
Questions:
What are the next steps?
Do I need a local running server of New Relic as I did for Prometheus?
Where can I visualize this data? I have an account in New Relic, I see nothing there
https://discuss.newrelic.com/t/integrate-spring-boot-actuator-with-new-relic/126732
As per the above link, Spring Bootctuator pushes metric as an event type “SpringBootSample”.
With NRQL query we can confirm this-
FROM SpringBootSample SELECT max(value) TIMESERIES 1 minute WHERE metricName = 'jvmMemoryCommitted'
What does the result of this query indicate? Is it a metric related to my application?
Here is the GitHub link to the demo that I have shared here.
I did not find any clear instructions on this, there are some examples out there but that uses Java agent.
Any kind of help will be highly appreciated.

From what I have learned so far.
There are 3 ways to integrate New Relic with a Spring Boot Application-
Using the Java Agent provided by New Relic
Using New Relic's Micrometer Dependency
Micormeter's New Relic Dependency
1. Configuration using Java Agent Provided By New Relic
Download the Java Agent from this URL- https://docs.newrelic.com/docs/release-notes/agent-release-notes/java-release-notes/
Extract it.
Modify the newrelic.yml file inside the extracted folder to inlcude your
license_key:
app_name:
Create a SpringBoot application with some REST endpoints.
Build the application.
Navigate to the root path where you have extracted the newrelic java agent.
Enter this command
java -javagent:<path to your new relic jar>\newrelic.jar -jar <path to your application jar>\<you rapplication jar name>.jar
To view the application metrics-
Log in to your New Relic account.
Go to Explorer Tab.
Click on Services-APM
You can see the name of your application(which you had mentioned in the newrelic.yml file) listed there.
Click on the application name.
The dashboard should look something like this.
Using New Relic's Micrometer Dependency is the preferred way to do it.
2. Configuration using New Relic's Micrometer Dependency
Add this dependency
<dependency>
<groupId>com.newrelic.telemetry</groupId>
<artifactId>micrometer-registry-new-relic</artifactId>
<version>0.7.0</version>
</dependency>
Modify the MicrometerConfig.java class to add your API Key and Application name.
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.springframework.boot.actuate.autoconfigure.metrics.CompositeMeterRegistryAutoConfiguration;
import org.springframework.boot.actuate.autoconfigure.metrics.MetricsAutoConfiguration;
import org.springframework.boot.actuate.autoconfigure.metrics.export.simple.SimpleMetricsExportAutoConfiguration;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.AutoConfigureBefore;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.newrelic.telemetry.Attributes;
import com.newrelic.telemetry.micrometer.NewRelicRegistry;
import com.newrelic.telemetry.micrometer.NewRelicRegistryConfig;
import java.time.Duration;
import io.micrometer.core.instrument.config.MeterFilter;
import io.micrometer.core.instrument.util.NamedThreadFactory;
#Configuration
#AutoConfigureBefore({ CompositeMeterRegistryAutoConfiguration.class, SimpleMetricsExportAutoConfiguration.class })
#AutoConfigureAfter(MetricsAutoConfiguration.class)
#ConditionalOnClass(NewRelicRegistry.class)
public class MicrometerConfig {
#Bean
public NewRelicRegistryConfig newRelicConfig() {
return new NewRelicRegistryConfig() {
#Override
public String get(String key) {
return null;
}
#Override
public String apiKey() {
return "your_api_key"; // for production purposes take it from config file
}
#Override
public Duration step() {
return Duration.ofSeconds(5);
}
#Override
public String serviceName() {
return "your_service_name"; // take it from config file
}
};
}
#Bean
public NewRelicRegistry newRelicMeterRegistry(NewRelicRegistryConfig config) throws UnknownHostException {
NewRelicRegistry newRelicRegistry = NewRelicRegistry.builder(config)
.commonAttributes(new Attributes().put("host", InetAddress.getLocalHost().getHostName())).build();
newRelicRegistry.config().meterFilter(MeterFilter.ignoreTags("plz_ignore_me"));
newRelicRegistry.config().meterFilter(MeterFilter.denyNameStartsWith("jvm.threads"));
newRelicRegistry.start(new NamedThreadFactory("newrelic.micrometer.registry"));
return newRelicRegistry;
}
}
Run the application.
To view the Application metrics-
Log in to your New Relic account.
Go to Explorer Tab.
Click on Services-OpenTelemetry
You can see the name of your application(which you had mentioned in the MicrometerConfig file) listed there.
Click on the application name.
The dashboard should look something like this.

What are the next steps?
It seems you are done and successfully shipped metrics to NewRelic.
Do I need a local running server of New Relic as I did for Prometheus?
No, NewRelic is a SaaS offering.
Where can I visualize this data? I have an account in New Relic, I see nothing there
It seems you already found it (screenshot).
What does the result of this query indicate? Is it a metric related to my application?
From the screenshot, I can't tell if it is your application but this seems to be the jvm.memory.committed metric pushed by a Spring Boot app (so likely).
In order to see if this is your app or not, you can add common tags which can tell the name of the app and some kind of an instance ID (or hostname?) in case you have multiple instances from the same app, see:
Spring Boot Docs (I would do this)
Micrometer Docs (do this if you don't use Spring Boot or want to do something tricky)
Real-World Example

Package not found when create data source using camel

I tried to replicate the same example given in the following question.
import javax.sql.DataSource;
import org.apache.camel.main.Main;
import org.apache.camel.builder.RouteBuilder;
import org.apache.commons.dbcp.BasicDataSource;
public class JDBCExample {
private Main main;
public static void main(String[] args) throws Exception {
JDBCExample example = new JDBCExample();
example.boot();
}
public void boot() throws Exception {
// create a Main instance
main = new Main();
// enable hangup support so you can press ctrl + c to terminate the JVM
main.enableHangupSupport();
String url = "jdbc:oracle:thin:#MYSERVER:1521:myDB";
DataSource dataSource = setupDataSource(url);
// bind dataSource into the registery
main.bind("myDataSource", dataSource);
// add routes
main.addRouteBuilder(new MyRouteBuilder());
// run until you terminate the JVM
System.out.println("Starting Camel. Use ctrl + c to terminate the JVM.\n");
main.run();
}
class MyRouteBuilder extends RouteBuilder {
public void configure() {
String dst = "C:/Local Disk E/TestData/Destination";
from("direct:myTable")
.setBody(constant("select * from myTable"))
.to("jdbc:myDataSource")
.to("file:" + dst);
}
}
private DataSource setupDataSource(String connectURI) {
BasicDataSource ds = new BasicDataSource();
ds.setDriverClassName("oracle.jdbc.driver.OracleDriver");
ds.setUsername("sa");
ds.setPassword("devon1");
ds.setUrl(connectURI);
return ds;
}
}
I have included the camel-jdbc-3.0.1.jar and my db specific jar file in my class path.
When I try to compile the code using the following command
javac -cp .;D:\Code\bin JDBCExample.java
I am getting the following error.
JDBCExample.java:2: error: package org.apache.camel.main does not exist
import org.apache.camel.main.Main;
^
JDBCExample.java:3: error: package org.apache.camel.builder does not exist
import org.apache.camel.builder.RouteBuilder;
^
JDBCExample.java:4: error: package org.apache.commons.dbcp does not exist
import org.apache.commons.dbcp.BasicDataSource;
Where am I going wrong? I tried adding camel-core to the classpath, but it didn't help.
Kindly let me know your thoughts, thanks in advance.

You did well by adding camel-core to your classpath, but camel-core and camel-jdbc do not suffice, you should also add the following dependencies:
JDBCExample.java:2: error: package org.apache.camel.main does not exist
import org.apache.camel.main.Main;
Add camel-main dependency
JDBCExample.java:4: error: package org.apache.commons.dbcp does not exist
import org.apache.commons.dbcp.BasicDataSource;
Add commons-dbcp dependency
JDBCExample.java:3: error: package org.apache.camel.builder does not exist
import org.apache.camel.builder.RouteBuilder;
Add camel-core dependency
With these and the camel-jdbc dependency, you are good to go.
I suggest that you use maven to handle your dependencies (and much more) if you can... If you have not used it before this five minutes quickstart will gently introduce you to it.
Here is a sample pom.xml that resolves all these dependencies correctly
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>demo</groupId>
<artifactId>camel-jdbc-demo</artifactId>
<packaging>jar</packaging>
<version>1.0-SNAPSHOT</version>
<name>camel-jdbc-demo</name>
<url>http://maven.apache.org</url>
<dependencies>
<!-- https://mvnrepository.com/artifact/commons-dbcp/commons-dbcp -->
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.4</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.camel/camel-main -->
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-main</artifactId>
<version>3.0.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.camel/camel-core -->
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-core</artifactId>
<version>3.0.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.camel/camel-jdbc -->
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jdbc</artifactId>
<version>3.0.1</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>

How to run jsoup code from maven in Eclipse?

I created a new maven project in Eclipse and created a file Main.java under src/main/java/parser. Here the package is parser in which my Main.java file is located. Here are the contents of Main.java, which is an example from Jsoup website.
package parser;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class Main {
public static void main(String[] args) throws Exception {
Document doc = Jsoup.connect("http://en.wikipedia.org/").get();
System.out.println(doc.title());
Elements newsHeadlines = doc.select("#mp-itn b a");
for (Element headline : newsHeadlines) {
System.out.println(headline.attr("title") + "\n\t" + headline.absUrl("href"));
}
}
}
Here is the pom.xml file:
<project
xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.test</groupId>
<artifactId>mdlparser</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency>
<!-- jsoup HTML parser library # https://jsoup.org/ -->
<groupId>org.jsoup</groupId>
<artifactId>jsoup</artifactId>
<version>1.11.3</version>
</dependency>
</dependencies>
</project>
Now, how can I run this project? I right clicked pom.xml file and hit Maven Build which opened run configuration window. What am I supposed to type here? I tried typing package and eclipse:eclipse. In both cases, the console's output says that the build was successful, but the output from my program(System.out.println) is not being shown in the console. Also I tried running it as simple java application but in that case I get NoClassDefFoundError.
Note: I know that you usually use a logger instead of using sysout. But I am really confused as to how to run this simple hello world like program.

Selenium Maven Setup - One Empty Jar

I'm trying to set up a Java Selenium test using the recommended Maven instructions found here:
http://docs.seleniumhq.org/docs/03_webdriver.jsp
and here:
http://docs.seleniumhq.org/download/maven.jsp
I have maven installed and working.
I've copied the example pom.xml, changing only the project name
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>SeleniumTest</groupId>
<artifactId>SeleniumTest</artifactId>
<version>1.0</version>
<dependencies>
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-java</artifactId>
<version>2.44.0</version>
</dependency>
<dependency>
<groupId>com.opera</groupId>
<artifactId>operadriver</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.opera</groupId>
<artifactId>operadriver</artifactId>
<version>1.5</version>
<exclusions>
<exclusion>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-remote-driver</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
</dependencyManagement>
</project>
Using
mvn clean install
runs without any errors. The target directory is created, containing SeleniumTest-1.0.jar and the maven-archiver directory. The problem is that my Eclipse project can't resolve the Selenium classes. I've copied the example Java driver class, modifying the imports based on my project layout:
import Selenium.*;
import Selenium.target.*;
public class Selenium2Example {
public static void main(String[] args) {
// Create a new instance of the Firefox driver
// Notice that the remainder of the code relies on the interface,
// not the implementation.
WebDriver driver = new FirefoxDriver();
// And now use this to visit Google
driver.get("http://www.google.com");
// Alternatively the same thing can be done like this
// driver.navigate().to("http://www.google.com");
// Find the text input element by its name
WebElement element = driver.findElement(By.name("q"));
// Enter something to search for
element.sendKeys("Cheese!");
// Now submit the form. WebDriver will find the form for us from the element
element.submit();
// Check the title of the page
System.out.println("Page title is: " + driver.getTitle());
// Google's search is rendered dynamically with JavaScript.
// Wait for the page to load, timeout after 10 seconds
(new WebDriverWait(driver, 10)).until(new ExpectedCondition<Boolean>() {
public Boolean apply(WebDriver d) {
return d.getTitle().toLowerCase().startsWith("cheese!");
}
});
// Should see: "cheese! - Google Search"
System.out.println("Page title is: " + driver.getTitle());
//Close the browser
driver.quit();
}
}
The classes "WebDriver", "WebElement", "WebDriverWait", and "ExpectedCondition" can't be resolved. Trying to use the imports in the example
import Selenium.By;
import Selenium.WebDriver;
import Selenium.WebElement;
import Selenium.firefox.FirefoxDriver;
import Selenium.support.ui.ExpectedCondition;
import Selenium.support.ui.WebDriverWait;
all fail.
I looked into the jar downloaded by Maven, SeleniumTest-1.0.jar, and it is effectively empty. It only contains the META-INF directory.
I feel like I'm missing something obvious, but I just can't figure it out. I feel like I'm missing something in my pom.xml, but I can't find anything on Selenium's site that helps. Can anyone give me a hand?