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Why doesn't my external Java file get compiled by the main program, when it imports a class that I've built, even if it's in the same package?

I'm building a program that needs to compile a Java file saved in an external package and execute it. The issue that I'm having is that the external file needs to import a class that I've built, but whenever I specify the import at the beginning of the code, the main class doesn't compile the external Java file.
However, if I remove the import from the external file, it compiles without issues.
This is the code:
Main class
package zhrfrd.jrobots;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
public class JRobots {
public static void main(String[] args) throws IOException {
// Compile and execute external java program
try {
Process processCompilation = Runtime.getRuntime().exec("javac -d /Users/faridzouheir/eclipse-workspace/JRobots/src/ /Users/faridzouheir/eclipse-workspace/JRobots/src/zhrfrd/testjrobots/Test.java"); // Compile Test.java
processCompilation.waitFor(); // Wait until the process is terminated before starting the following process (to avoid the second process not working properly)
Process processExecution = Runtime.getRuntime().exec("java -cp /Users/faridzouheir/eclipse-workspace/JRobots/src/ zhrfrd.testjrobots.Test"); // Execute java (-cp is class path)
BufferedReader in = new BufferedReader(new InputStreamReader(processExecution.getInputStream())); // Get result of the execution of the external file
String line = null;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
System.out.println("Execution error.");
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("Interrupted exception.");
}
}
}
External file to be executed (Test)
package zhrfrd.testjrobots;
import java.io.IOException;
import zhrfrd.jrobots.Robot; //This is the import that doesn't allow the compilation
public class Test{
private static final long serialVersionUID = 1L;
static Robot rob;
public static void main(String[] args) throws IOException {
Robot rob;
int a = 300;
int b = 23;
int res = doSum(a, b);
System.out.println(res);
// boom();
rob = new Robot();
rob.boom();
}
public static int doSum(int a, int b) {
return a + b;
}
}
Robot class
package zhrfrd.jrobots;
import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
public class Robot extends JLabel implements Runnable{
protected static final long serialVersionUID = 1L;
protected int life, direction, speed, posX, posY;
protected Thread threadRobot;
private Random random;
private Dimension size;
// Constructor
public Robot() throws IOException {
this.life = 100;
threadRobot = new Thread(this, "My thread");
}
// Methods
//Set robot position
public void setPosition() {
random = new Random();
posX = random.nextInt(500);
posY = random.nextInt(500);
size = this.getPreferredSize();
this.setBounds(posX, posY, size.width, size.height);
System.out.println(posX);
}
//TEST METHOD
public void boom() {
System.out.println("BOOM BOOM!!");
}
#Override
public void run () {
System.out.println(threadRobot.getName());
setPosition();
}
}
Note: I tried to move the Robot class inside the same package of the Test file but it still doesn't work. Also, in case I want to remove the main method from the Test file and make it as a subclass of Robot, is it still possible to compile it and execute it.

I finally managed to fix the issue. Inside the main class when I run the command to compile the Test class, I didn't specified the path for the Robot class (imported by the Test class):
Process processCompilation = Runtime.getRuntime().exec("javac -d /Users/faridzouheir/eclipse-workspace/JRobots/src/ /Users/faridzouheir/eclipse-workspace/JRobots/src/zhrfrd/testjrobots/Test.java");
In order to fix it I simply add it to the command:
Process processCompilation = Runtime.getRuntime().exec("javac -d /Users/faridzouheir/eclipse-workspace/JRobots/src/ /Users/faridzouheir/eclipse-workspace/JRobots/src/zhrfrd/testjrobots/Test.java");

why isn't my config file modifying my servers motd?

So as the title says I need my config file to modify my servers motd, I feel like I've done everything the right way but obviously something is wrong, so let me show you what I'm working with
me.zavage.motd.Main
package me.zavage.motd;
import org.bukkit.plugin.java.JavaPlugin;
public class Main extends JavaPlugin {
#Override
public void onEnable() {
saveDefaultConfig();
}
}
me.zavage.motd.listeners.PingListener
package me.zavage.motd.listeners;
import java.io.File;
import org.bukkit.Bukkit;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.server.ServerListPingEvent;
import me.zavage.motd.Main;
import me.zavage.motd.utils.Utils;
public class PingListener implements Listener {
private Main plugin;
#EventHandler
public void onPing(ServerListPingEvent e) {
e.setMaxPlayers(plugin.getConfig().getInt("maxplayers"));
e.setMotd(Utils.chat(plugin.getConfig().getString("motd" + "\n" + (Utils.chat(plugin.getConfig().getString("motd_line_2"))))));
try {
e.setServerIcon(Bukkit.loadServerIcon(new File(plugin.getConfig().getString("server_icon_path"))));
} catch (Exception e1) {
e1.printStackTrace();
}
}
}
Then we have the config.yml
#can only be a NUMBER with NO DECIMALS!
maxplayers: ''
motd: ''
#next line on motd
motd_line_2:
#create a folder inside the first page of your server files, call it "icon" and drop you server icon in there
#server icon MUST be 64 x 64 pixels
# #NameOfIcon#
#path example "C:\Users\user\Desktop\minecraft test server\icon\icon.png
server_icon_path: ''

If the code that you show if everything that you are using, there is few issues.
You don't register the listener
package me.zavage.motd;
import org.bukkit.plugin.java.JavaPlugin;
public class Main extends JavaPlugin {
#Override
public void onEnable() {
saveDefaultConfig();
getServer().getPluginManager().registerEvents(new PingListener(this), this);
}
}
You don't set the plugin variable in the listener, and you don't have constructor
public class PingListener implements Listener {
private Main plugin;
public PingListener(Main plugin) {
this.plugin = plugin;
}
}
Finally, you are searching for the motd\n motd_line_2 message. You have to use this in your ServerListPingEvent listener :
e.setMaxPlayers(plugin.getConfig().getInt("maxplayers"));
e.setMotd(Utils.chat(plugin.getConfig().getString("motd") + "\n" + plugin.getConfig().getString("motd_line_2")));
try {
e.setServerIcon(Bukkit.loadServerIcon(new File(plugin.getConfig().getString("server_icon_path"))));
} catch (Exception exc) {
exc.printStackTrace();
}

How to solve error given by eclipse on running runClient?

I am trying to make a basic mod for minecraft and am following a tutorial for the same. When I run runClient, it gives me the following error
Reference to undefined variable MC_VERSION
Here is my main.java for reference:
package rattandeep.basicmod;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.common.Mod.EventHandler;
import net.minecraftforge.fml.common.Mod.Instance;
import net.minecraftforge.fml.common.SidedProxy;
import net.minecraftforge.fml.common.event.FMLInitializationEvent;
import net.minecraftforge.fml.common.event.FMLPostInitializationEvent;
import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
import rattandeep.basicmod.proxy.CommonProxy;
import rattandeep.basicmod.util.Reference;
#Mod(modid = Reference.MOD_ID, name = Reference.NAME, version = Reference.VERSION)
public class Main {
#Instance
public static Main instance;
#SidedProxy(clientSide = Reference.CLIENT_PROXY_CLASS, serverSide = Reference.COMMON_PROXY_CLASS)
public static CommonProxy proxy;
#EventHandler
public static void PreInit(FMLPreInitializationEvent event) {
}
#EventHandler
public static void init(FMLInitializationEvent event) {
}
#EventHandler
public static void Postinit(FMLPostInitializationEvent event) {
}
}
I have searched for a solution but found none. How do I solve this?

I found out how to solve it. I just needed to change the variable value of MC_VERSION in my runClient launch file to my minecraft version.

Using Windows Task Scheduler to automate execution of WAR file

My application is written with Spring, Hibernate (JPA), JBOSS 9.0.0.GA & JBOSS EAP 6.4. In POM.xml I have specified the packaging to WAR.
I have 2 functions which I'd like to automate:
a. CSV reader - Read from CSV file and update table in DB
package com.fwd.pmap.memberInterfaceFile;
/* all imports */
public class CsvReader
{
public void importInterfaceFile() throws Exception
{
// do processing here
}
}
b. CSV Writer - Read from DB and output to CSV file
package com.fwd.pmap.memberInterfaceFile;
/* all imports */
public class CsvWriter
{
public void generateInterfaceFile() throws Exception
{
// do processing here
}
}
How can I automate both functions above to run on a specific time every day? For example:
CSV Reader to run daily # 05:00 AM
CSV Writer to run daily # 07:00 AM
Project Structure

Finally decided to use Spring Scheduling as it does not involve lots of coding as well as XML.
This is the bean class where I schedule 2 jobs to run at 5AM & 6AM daily:
package com.fwd.pmap.scheduler;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import com.fwd.pmap.memberInterfaceFile.CsvReader;
import com.fwd.pmap.memberInterfaceFile.CsvWriter;;
#Component
public class MyBean {
#Scheduled(cron="0 0 5 * * *")
public void importInterfaceFile()
{
CsvReader reader = new CsvReader();
try {
reader.importInterfaceFile();
} catch (Exception e) {
e.printStackTrace();
}
}
#Scheduled(cron="0 0 6 * * *")
public void generateInterfaceFile()
{
CsvWriter writer = new CsvWriter();
try {
writer.generateInterfaceFile();
} catch (Exception e) {
e.printStackTrace();
}
}
}
Here's the config class:
package com.fwd.pmap.scheduler;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import com.fwd.pmap.scheduler.MyBean;
#Configuration
#EnableScheduling
public class SchedulerConfig implements SchedulingConfigurer {
#Bean
public MyBean bean() {
return new MyBean();
}
#Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
taskRegistrar.setScheduler(taskExecutor());
}
#Bean(destroyMethod="shutdown")
public Executor taskExecutor() {
return Executors.newScheduledThreadPool(4);
}
}
And the main class to execute the above:
package main;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import com.fwd.pmap.scheduler.SchedulerConfig;
public class Main {
static Logger LOGGER = LoggerFactory.getLogger(Main.class);
#SuppressWarnings({ "unused", "resource" })
public static void main(String[] args) {
AbstractApplicationContext context = new AnnotationConfigApplicationContext(SchedulerConfig.class);
}
}

java program not able to access another class from same package when compiled from command prompt

I have two classes in a package. One class contained two methods. I am calling these methods in second class. On compiling from command prompt its showing error on first class name. Its running fine on Intellij though.
package with 2 classes - test2.java, test1.java
on compiling test1.java on cmd i m getting below error:
root#a TagPackage]# javac -classpath "/home/admin/TagAPI/lib/*" Test1.java
Test1.java:9: cannot find symbol
symbol : class Test2
location: class TagPackage.Test2
Test2 s= newTest2();
Any suggestions will be helpful.
package TagPackage;
import java.io.IOException;
public class Test2 {
public String getControlBlock(String url) throws IOException {
xcv...
}
public void validate(String url, String ResponseCB) throws
IOException, JSONException {
xzq...
}
}
package TagPackage;
import org.json.JSONException;
import java.io.IOException;
public class Test1 {
Test2 s = new Test2();
public static void main (String[] args) {
Test1 a = new Test1();
try {
a.testMethod();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
System.out.println("Testmethod 1 out");
}
public void testMethod()throws IOException, JSONException {
String url = "dsadas";
String ResponseCB = s.getControlBlock(url);
s.validateurl, ResponseCB);
System.out.println("Testmethod 1 reached here123");
System.out.println("Testmethod 1 out");
}

You need to run the compiler from the directory that contains TestPackage, and you therefore also need to specify TestPackage/Test1.java as the file to compile.
This is all documented.

I recommend you to create a new project with default package and save your class in it.It worked for me :)