System.out.println - Hello World Example

Hi All
I am using Apache Tomcat and trying t produce a simple output to the browser. Cannot get System.out.println to work. See code and out below:
begin code
<HTML>
<HEAD><TITLE>hello jsp</TITLE></HEAD>
<BODY>
<%@ page language='java' contentType='text/html' %>
<%
String message = "Hello World";
message = message + "\nAFTER";
System.out.println("BEFORE");
%>
<%= (message) %>
</BODY>
</HTML>
END code
--begin browser output
Hello World AFTER
end browser ouput
Would be grateful if someone could explain why the System.out.print statement cannot be seen in the browser output.
many thanks
Naresh

System.out prints to System.out. What that is depends:
In applets, (which the OP was not talking about) it is the Java Console.
In JSP, it's the same as any application by default.
You can change in Java what System.out prints to, but you don't often do this. But in JSP it doesn't print to the browser. JSP is not CGI, which does you the standard out as the destination for written data.

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What does System.out.println("Hello world!"); when System.console()=null?

Hello,
the code below:
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        outStream.println(System.currentTimeMillis());
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java.io.PrintStream@190d11
So it looks like System.out is valid and usable, however, since the application as no console, where I can see the output ???
Precision: I get this situation in the main function of a console application which I launch using Process.Start. Is there any way to get a console by this mean ?
Best regards,
Sebastien

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import java.util.*;
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How does System.out.println(). Work inside src.zip file !

Hello guyz,
I was just wondering how System.out.println() worked so i opened up the src.zip file and checked the source code. But could not understand it. As written i remember
"out is an object encapsulated in the System class."
Thats ok. But i could not understand the code.
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    private static PrintStream nullPrintStream() throws NullPointerException {
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public class One
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import java.io.PrintStream;
public class One
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Peter__Lawrey wrote:
I was just wondering how System.out.println() worked so i opened up the src.zip file and checked the source code.This value is a place holder. This value is changed as soon as enough of the JVM is initialised for printing to work.
Also, why does it need to import PrintStream ? It doesn't, but it is used in the code so DJ is including it just in case.Sorry,
But i don't understand at all.

Using System.out.println() in Scrapbook

I am working through some tutorials on formatting numbers:
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It seems that the format method returns the PrintStream (allowing you to chain method calls), and the return value is being printed.
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System.out.println method

hi, i am new to java. plz help...thx
i would to do the following task.
i would like to print "hello world" every 1 second, such that:
while(true){
System.out.println("hello world\n");
--> wait for one second;
how to write the "wait for one second coding"?
thx all , and urgent...

You can use Thread.sleep(1000) to wait.
However, Thread.sleep(1000) cannot wait exact 1 sec.
while (true) {
System.out.println("...");
try {
Thread.sleep(1000);
catch (Exception ex) {}
And you don't need to use '\n' because println() prints always '\n'.

Problems with System.out.println()

I tried writing a simple 'Hello world'-program:
public class Test{
     public static void main(String[] args){
          System.out.println("Hello World!");
     }//main()
}//Test
But the text wouldn't appear in the DOS-window. The only text that showed up was the standard 'Press any key to close the window'. The program compiled without any problems, but didn't work when I tried to run it.
Does anyone have any idea what's wrong?

Are u sure , the main() class part is donecorrectly.
Becuse program will compile but not run without a
main() class.what do you mean by main() class???First of all main() is a method, not a class. The main() method the JRE recognizes and runs is the:
public static void main(String[] params)
If you don�t have exaclty those modifiers and receive an array of Strings parameter it will send you an runtime exception.
Your code compiles and runs fine, the problem isn�t really System.out.print() it is something with your configuration.
I have to rename the class to TestF. Here is the running:
C:\cJava>javac TestF.java
C:\cJava>java TestF
Hello World!

Help: What can make "System.out.println" not displaying anything?

Hello,
We have Portal 10g.
I have noticed a pb on the interpretation of existing JSP pages.
I simplified the code... and I noticed that even this command doesn't work :
<%
System.out.println("Hello World");
%>
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Is there any security ? permission I should get ?
JSP works fine on our old 8i environment ...
Thanks in advance for your help.
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Olivier,
between 8i and 10g are aeons of time (for computer technology). As far as I recall, in 8i came with a Apache and JServ module. This supported Servlets and JSP through a special Oracle implementation. After that OC4J as a J2EE container for EJBs and Servlets/JSPs was introduced.
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HTH,
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Why doesn't System.out.println work for Palm?

In my Java code,
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System.out.println("Hello World");
Where is the output really going to???

Hi,
On POSE (Palm OS emulator), the System.out.println() method output is a file called STDOUT.txt, filed in some directory of the emulator.
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Ricardo

System.out.printf vs System.out.println

Hello!
I would like to know which is faster: printf or println.
eg:
System.out.println("Hello " + "World");
System.out.printf("Hello %s", "World");
I think that println is faster, because it doesn't have to look for format parameters and then the arguments. But of course, there're sometimes that you need to use printf (System.out.printf("Wage %.2f", wage));
Well...I just asking it, because How To Program uses it a lot, maybe it's only teaching purpose.

Encephalopathic wrote:
Sounds like a micro-optimization question to me where the answer is either mu or is very close to mu. IMHO, it's much better to ask which code is more understandable to me and to others helping me since that's more of a rate-limiting step in code development.Agreed. Printing to the console is not something where you need to measure performance (unless you're trying to gauge whether or not printing to the console is going to slow you down, in which case it 99.9% of the time will).

System.out.println and log file

          I am developing jsp on BEA Weblogic 613 on Solaris.
          What if i run the following statement
          System.out.println("Hello world");
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          sent to? If not, is there anyway to redirect output from the console to someplace
          else?
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You can redirect console output for stdout on Solaris like so:
          java weblogic.Server > consoleoutput.txt
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          Sam
          Brian Schneider wrote:
          > I am developing jsp on BEA Weblogic 613 on Solaris.
          >
          > What if i run the following statement
          > System.out.println("Hello world");
          >
          > I understand that Hello World will be printed to the server console. I do not
          > have access to this console. Is there any log file or temporary log file it gets
          > sent to? If not, is there anyway to redirect output from the console to someplace
          > else?
          >
          > Thanks!

System.out.println means

Can any one explain what is "system.out.println"
i need to know each individual li,e "System" means what , form which class and why it is used
simillary for "out" and "println"

There is a class called System.
It has a static member attribute called "out", which is of type PrintStream.
PrintStream provides a method called "println", which is what you're calling.
Here's a similar example:
// This is playing the role of PrintStream
public class Foo {
   // This method is playing the role of println()
   public void bar() {
      System.out.println("Hello");
// This is playing the role of System
public class Test {
   // This attribute is playing the role of the out attribute in the System class
   public static Foo out = new Foo();
// Here's the code to go with it:
Test.out.bar(); // Prints "Hello"See the similarity ?
Test.out.bar();versus
System.out.println("...");The documentation for the System class is here:
http://java.sun.com/j2se/1.4.2/docs/api/java/lang/System.html
The documentation for all the rest of the classes is here:
http://java.sun.com/j2se/1.4.2/docs/api/index.html

System.out.println() in JUnit

Hi Everybody,
Can you please solve my confusion, weather System.out.println(); will work in JUnit or not.
When I wrote System.out.println in Junit i am not getting anything.
Thanks in advance
Ananda

Junit is also a java class which extends the junit.framework.TestCase.
So the System.out.println() method always works in the junit class.
Try this code:
import junit.framework.TestCase;
public class TestJUnitTest extends TestCase {
     public void testCase1() {
          System.out.println("hello");
          assertEquals(true, true);
}

Can't run java apps with System.out.println on any builder.

Hello,
I'm currently using Vista RC2, which is the immediate problem.
Classes with System.out.println won't launch the console window. As I'm a student and practicing on these steps, I do have quite a problem on my hands. I click on run, build succesfull, nothing happens.
I have tried Netbeans and Jcreator, and gave up on trying different builds, as I reckon I'll have to find some other way to counter this; any way to get println messages working in vista?

It is run as a desktop app, and other runs with commands such as JOptionPane do function, only the println windows don't appear at all. So I think JRE is installed and working.
I did notice there was one command for input where I'd be able to enter it at the bottom of Netbeans.
Like just now I clicked build and run for the following code
import java.util.*;
public class FirstProgram
    public static void main(String[] args)
        System.out.println("Hello out there.");
        System.out.println("I will add two numbers for you.");
        System.out.println("Enter two whole numbers on a line:");
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        Scanner keyboard = new Scanner(System.in);
        n1=keyboard.nextInt();
        n2=keyboard.nextInt();
        System.out.println("The sum of those two numbers is");
        System.out.println(n1+n2)
}Resulting in a brief flash of "input" in the output window (which is below the coding window) and it dissapears. But this also occurs when I don't include system scanner code.
Using commands in cmd
java -jar "C:\Users\Alegis\Netb\MyApp\dist\MyApp.jar"
Does not yield desired results either. Nothing happens.

Where do Java Embedding "System.out.println()" go? Where is Java Console?

Assume I embed a "Java Embedding" object in a BPEL process
and write the following Java code into it:
System.out.println("Hello BPEL");
where does this text go when executed? If I remember it well there must be somewhere an AppServer console.
But where is it exactly ?
Peter

Hi Peter,
The out stream is generally redirect into files in applications servers.
OC4J : $ORACLE_HOME/opmn/logs/<your_group>~<your_home_name>~<your_group>~1.log
WebSphere : $LOG_ROOT/SystemOut.log
JBoss : $SERVER_LOG_ROOT/server.log
Hope this helps.
Regards,
Raphaël
http://bpelsoa.blogspot.com

System.out.println does not print out anything

I'm wonder why the dos mode does not print out the System.out.println.
My code has:
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class test extends HttpServlet {
   public void doGet(HttpServletRequest request,
   HttpServletResponse response) throws IOException,
   ServletException {
      System.out.println("Hello");
The compilation is ok... but it does not display anything... how come?

"System.out.print()" prints to the log file of the tomcat server. in order to print on the screen use JspWriter.
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class test extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response) throws IOException,
ServletException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("Hello");
//System.out.println("Hello");
Hope this helps!

System.out.println - Hello World Example

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