The topic is very easy and i am sure that lots of java programmer already know how to compile java program existing in package. However there are users who frequently works on eclipse, netbeans or any other IDE and don’t know that how the program actually works behind the IDE. So this article basically emphasizes on basics of Java Compilation.
Consider following directory structure :
Our java files will be in “src” folder. I want all the class files in folder “classes” and currently i am in folder “Exec Jar“.
Consider below Java Files:
Person.java
package com.g2.ExecJar;
public class Person {
private String name;
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
Start.java
package com.g2.ExecJar;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Start {
public static void main(String[] args) {
try {
InputStreamReader io = new InputStreamReader( System.in );
BufferedReader read = new BufferedReader(io);
System.out.println("Enter Name");
Person p = new Person();
p.setName(read.readLine());
System.out.println("Enter Age");
p.setAge(Integer.parseInt( read.readLine()) );
System.out.println( "-------- You have Eneterd --------- " );
System.out.println("Name : " + p.getName());
System.out.println("Age : " + p.getAge());
System.out.println( "---------- Progarm run by executable jar ------------ " );
} catch (IOException e) {
e.printStackTrace();
} catch (NumberFormatException e) {
System.out.println("Age entered is not in correct format");
}
}
}
Run below steps to compile and run java programs from command line:
Command Explanation :
Line 1 :
- “javac” is the java compiler available in bin folder of the jdk.
- “-d” stands for the “directory“. it explains compiler that where the class files should be created.
- Last argument is the Complete path, where the java file exists.
Line 2 :
- in line 2, you have noted one extra parameter “-classpath“. As class “Start” depends on class “Person” and its class file is not in the same directory. Therefore we need to explicitly tell compiler that where it can find required class files.
- To include more than one classpath use semicolon “;”. Example: -classpath path1;path2;path3
Line 3 :
- It will run the program. her we have to again specify that where all the class files exist with the help of parameter “-classpath“
The complete set of argument supported by the java compiler can be found on the Oracle site.
Next article, How to create executable jar file for packages in java
if have another directory to execute the java program
to compile the program
c:/>javac -cp d:sub;. use.java
to execute the program
c:/>java -cp d:sub;. use
hey can u clearly show us d command dt what’s d syntax to compile a program which use package….??
sorry we didnt understood ;;;;eplain clear whatever u want ………..
hard to understand….
Option -d works if the directory structure is already there.What if the directory structure doesn’t exist from before?
Not Complete Directory structure. You just need to give the root path for the “.class” files. Remaining folders will be automatically created as per package structure.
Regards,
Jitendra Zaa
Thanks…it’s workingÂ
can you please explain little more deeply…??? i can’t understand….can’t you give any example which uses package and importing a user defined package…???
-Thanks
Hi Rachana,
Please follow the steps as per article. I have included the screens also. It worked for everyone.
Regards,
Jitendra Zaa
yes its working by the way you said..but what should i have to do the class files are in the same package where he classes are stored. bcz i’m having two classes with in com.example.payroll. the first class employee.java has compiled successfully but when i try to compile Test.java which has initialization of an object employee class shows cannot find symbol error i don’t know what is the reason here.
please give some simple programe of packages
sir i m unable to compile and run java package in jdk1.77. so pls tell me sir how can compile and run packages in java.
Hi Rihan,
Please follow the exact steps with same folder name, if you still face any problem than attach your screen shot showing error. i will surely guide you.
Thanks,
Jitendra Zaa
package is hard to run help everyone who wants help thank
I know its hard to run, thats why i have provided article. I have provided screen shots with step by step description. Just follow the same folder names and instructions. If you get any error then reply with full description.
Regards,
Jitendra Zaa
sir how to run this program plssssssssssssss
//multiplication.java
package mp;
public class multiplication
{
int n;
public multiplication(int n)
{
this.n=n;
}
public void table()
{
if(n<=0)
{
System.out.println(n+"invalid input");
}
else
{
for (int i=1;i<=10 ;i++ )
{
System.out.println(n+"*"+i+"="+(n*i));
}
}
}
}
//Satyauser.java
import mp.multiplication;
class  Satyauser
{
public static void main(String[] args)Â
{
int n = Integer.parseInt(args[0]);
multiplication mo=new multiplication(n);
mo.table();
}
}
Hi Somasekharkote,It will need command line argument which will be converted as number and print the multiplication table.
Thank you for the good article, I was able to proceed further using this article, but I have getting this error (PFA screenshot)
I have my java file stored in                   C:UsersAshi’sworkspaceJavaPracticeMyPackÂ
and I have my java executable files stored at       C:Program FilesJavajdk1.7.0_02binÂ
Hi Add the path upto java/bin in “Classpath” and run the program from base package
Thank you for the reply Sir, but I did not understand what you mean by the above statement. Are you intending on going to my executable files folder and then using the classpath flag along with javac command? Really confused here 🙁
hmmmm okay
Thanks. It works… 🙂
Thanks Ran on Ubuntu 12.04 just as is. I did have to include all the directories to the source file.
b
thx a lot for this post, thx once again,
if i can write the both files (package & main class file) in one program then how to run this program.
It’s not working sir , I did the above step as you mention , It creating lot of confusion
package jp.co.global;
this is my package….. how shud i compile n run it?
my classname is Main
this is nt d pkg created by me… m preparing 4 a cmpny n it hs told 2 use dis pkg in d code
thanks
if i change the package name of Start.java then how to run it
You are a life saver man! Thanks a ton 🙂
Thanks 🙂
sir how to run this
import java.net.*;
import java.io.*;
import java.sql.*;
class trainserver
{
public static void main(String args[])
{
String Query;
ResultSet rs = null;
String msg;
int pnr = 0,trainnum=0;
String from = new String();
String to = new String();
String date = new String();
String name = new String();
try
{
ServerSocket ser=new ServerSocket(8000);
System.out.println(“Server Started…”);
Socket soc=null;
soc=ser.accept();
System.out.println(“Received Connection: “+soc.getInetAddress().getHostAddress());
DataOutputStream out=new DataOutputStream(soc.getOutputStream());
BufferedReader in = new BufferedReader(new InputStreamReader(soc.getInputStream()));
try{
Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”);
Connection conn=DriverManager.getConnection(“jdbc:odbc:mydb”,”scott”,”tiger”);
Statement stmt=conn.createStatement();
msg = in.readLine();
pnr = Integer.parseInt(msg);
Query = “Select * from train where pnrno = “+pnr;
rs = stmt.executeQuery(Query);
if(rs.next())
{
pnr = Integer.parseInt(rs.getString(1));
from = rs.getString(2);
to = rs.getString(3);
date = rs.getString(4);
name = rs.getString(5);
trainnum=Integer.parseInt(rs.getString(6));
}
else
{
System.out.println(“invalid PNRNO”);
}
}
catch(SQLException e)
{
System.out.println(“Error Caught: “+e);
}
out.writeBytes(“”.valueOf(pnr));
out.write(10);
out.writeBytes(from);
out.write(10);
out.writeBytes(to);
out.write(10);
out.writeBytes(date);
out.write(10);
out.writeBytes(name);
out.write(10);
out.writeBytes(“”.valueOf(trainnum));
out.write(10);
soc.close();
}
catch(Exception e)
{
System.out.println(“Error Caught: “+e);
}
}
}
//Client side
class traindbclient
{
public static void main(String args[])
{
Socket objclient= null;
BufferedReader br = null,in = null;
DataOutputStream out = null;
int pnr = 0;
try
{
objclient = new Socket(“Localhost”,8000);
in = new BufferedReader(new InputStreamReader(objclient.getInputStream()));
br = new BufferedReader(new InputStreamReader(System.in));
out = new DataOutputStream(objclient.getOutputStream());
System.out.println(“Enter the PNR NO: “);
pnr = Integer.parseInt(br.readLine());
out.flush();
out.writeBytes(“”.valueOf(pnr));
out.write(10);
System.out.println(“PNRNo: “+in.readLine());
System.out.println(“SOURCE : “+in.readLine());
System.out.println(“DESTINATION: “+in.readLine());
System.out.println(“JOURNEY DATE: “+in.readLine());
System.out.println(“CUSTOMER NAME: “+in.readLine());
System.out.println(“TRAIN NO: “+in.readLine());
objclient.close();
}
catch(Exception e)
{
System.out.println(“Error Caught: “+e);
}
}
}
please give me solution sir
thank you. Had been trying to do this for several hours until I read your post. You’re right here “…However there are users who frequently works on eclipse, netbeans or any other IDE and don’t know that how the program actually works behind the IDE…. “