It should work like system.out.println

hai my objective when i pass any string argument to myprint method it should work like system.out.println . but iam not getting out put . please any one help me
public void myprint(String data){
try{
byte[] bytearray = data.getBytes();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bos.write(bytearray,0,data.length());
PrintStream ps = new PrintStream(bos) ;
System.setOut(ps);
catch (Exception e){
e.printStackTrace();
}

Doesn't something seems out of order here?
1. This is not the correct forum.
2. You are writing the bytes to the ByteArrayOutputStream first and then setting to the System outputstream. Shouldn't it be the other way round?

Similar Messages

System.out.println stalls my jdev

Hello
Is there a bug database with regards to JDeveloper 3.0?? My JDev seems to stall when I attempt to type out a "System.out.println(..)" statement. Has anyone encountered something similar?? WinNt4.0 workstation (sp5)
Tia,
-Robert-

Same problem, NT 4.0. Often it stalls just when you type the open parenthesis prior to the string. My guess is it has something to do with the popup choices menu for that method. I don't know how to fix it but I'm using a clunky work-around by copying and pasting something like:
System.out.println("");
which includes the quotes inside the parentheses. That seems to keep the popup from trying to show up.

Why System.out.println not PrintStream.println ?

Hi, just a beginner question
I just wonder why should we use System.out.println, not PrintStream.println ?
the field out in the System class is the instance of PrintStream class, isn't it?
So why don't we just use the PrintStream class directly?
Thanks..
Edited by: riff_almighty on Oct 27, 2007 3:27 AM

According to the api:
A PrintStream adds functionality to another output stream, namely the ability to print representations of various data values conveniently. Two other features are provided as well. Unlike other output streams, a PrintStream never throws an IOException; instead, exceptional situations merely set an internal flag that can be tested via the checkError method. Optionally, a PrintStream can be created so as to flush automatically; this means that the flush method is automatically invoked after a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written.
So there is nowhere mentioned about the PrintStream associated with the user console. System.out is the one instance of PrintStream which is associated with the console...
Also println() is not a static method and cant be called upon the class...
Edited by: VijayBabu on Oct 27, 2007 12:51 AM

Which toString() method does System.out.println() call?

Which toString() method does System.out.println() call? I know that if I did something like System.out.println( new myClass() ) that the toString being called would be that of the myClass class.
My initial thought about this was that System.out.println() is the equivalent of System.out.println( new Object() ) but I remember trying that in a test program and it gave me a myClass@some_hash_code type of message when adding the new Object() part within the System.out.println().
Could someone please tell me which toString the System.out.println() statement calls? Also, it would be great if an elaboration follows :).
Any input woudl be greatly appreciated!
Thanks in advance!

s3a wrote:
My initial thought about this was that System.out.println() is the equivalent of System.out.println( new Object() ) Huh?
In one method call you pass no parameters in the other method call you pass one parameter. How could you possibly think that they would do the same thing?
Could someone please tell me which toString the System.out.println() statement calls? Also, it would be great if an elaboration follows :).Yes. The toString of the class of the object which you pass to the method. If that class does not have a toString method it uses the toString method it inherits from the parent class. If the parent class does not have a toString method it uses the one inherited and so and so on all the way up to the Object class.

Color System.out.println text?

Is there a way to set a color for my text using System.out.println("Text"); liek something like
System.out.println((setColor(Color.red)"text"));
or something?
Please respond as soon as possible

If you can use a JTextArea, try this:
import java.awt.*;
import javax.swing.*;
import javax.swing.text.*;
/** subclass of JTextArea allowing color attributes */
public class AttributedTextArea extends JTextArea
    private DefaultStyledDocument m_defaultStyledDocument=new DefaultStyledDocument();
    /** constructor */
    public AttributedTextArea()
        this.setDocument(m_defaultStyledDocument);
    /** append text */
    public void append(String string,Color color)
        try
            SimpleAttributeSet attr=new SimpleAttributeSet();
            StyleConstants.setBackground(attr,color);
            m_defaultStyledDocument.insertString(m_defaultStyledDocument.getLength(),string,attr);
        catch(Exception e)
            Messages.javaException(e);
    /** append text in default color */
    public void append(String string)
        append(string,Color.white);
}

System.out.println quotes

How do you print quotation marks? When I sayed
System.out.println (" "" + str1 + "" ") it gave me an error message
It should print
"hello"

System.out.println (" \"" + str1 + "\" ");

System.out.println () is not working properly

Hi, Why does this happens:
Object temp=null;
System.out.println ("temp is null? "+temp==null);
just prints: true
expected: temp is null? true
Why does this happens????
If I do System.out.println ("temp is null? "+(temp==null)); it works bu it should work without the pharentesis too

MelGohan wrote:
Hi, Why does this happens:
Object temp=null;
System.out.println ("temp is null? "+temp==null);
just prints: trueThat is odd, mine prints "false".
type Test126.java
public class Test126 {
    public static void main(String[] args) {
        Object temp=null;
        System.out.println ("temp is null? "+temp);
        System.out.println ("temp is null? "+temp==null);
}javac Test126.java
java Test126
temp is null? null
false

System.out.println makes things work fine????

I have a case where vector hasto be populated based on some condition. It is in a for loop.But it throws null pointer exception when i try to access the elements in the vector as its empty.So to check that i gave a System.out.println to check the values at the point of inserting the elements into the Vector.At this point it starts working fine.I got this problem 2-3 times.I checked if i missed out something.But that was not the case.A System.out.println was causing the values to be inserted into the vector. I then removed the SoPs and tried.It worked fine.Any Idea??????????this is causing headache for me.I am using eclipse and tomcat4.1 with jdk1.4.2

Honestly roshan, "I checked if i missed out something" and similar just isn't
enough.
You need to post code. Not 1500 lines but a small example that others can
compile and run to observe the behaviour that you observe.
Constructing such an example often helps in solving a problem. If the problem
goes away when you remove code that contains or calls the method in question
that's a sign of where the problem may lie (Even if that code seems to be
irrelevent).
The task of constructing a small example like this is not always easy: but it's
useful for you and essential for others.

32-bit JDK 7 System.out.println not working in IDE

Hi folks,
I have a 64-bit Windows 7 OS.
Due to 3rd party library/jar dependencies, i had to install the 32-bit Java JDK 1.7 and Eclipse IDE.
I also installed NetBeans.
So i have a 64-bit OS and am running 32-bit Java JDK/JRE & IDEs.
The problem I am having is that my program's System.out.println("...") statements are not outputting strings to either IDE debug console.
Executing the compiled program from a command line/prompt produces the expected string output.
The basic "Hello, World" program is enough to cause this behaviour to start occurring.
I have not manually / intentionally changed any IDE-specific Debug Console or Windows environment settings.
One caveat: This same environment has worked successfully in the past ?! Yes, this is one of those "..it worked last week & yesterday and today it isn't and i swear i didn't do anything..." issue.
Thoughts ?

Thanks for the reply.
The 64-bit versions of Java & Eclipse were installed first.
When i discovered I had to use the 32-bit versions, i un-installed the 64-bit ones & installed the 32-bits.
Even after that initial un-install 64-bit/install 32-bit process, it was working.
I have also been installing the Windows 7 64-bit OS updates when i am informed of them.
I'm not sure if any of these would affect how the Eclipse / NetBeans IDEs behave.
Behaviour has been inconsistent.
Initially it was always working.
But over the past several days, it has been working less and less.
I don't have any large data structures.
This isn't a large complicated program, couple hundred lines, so i highly doubt that i'm doing anything to the resources, but something has changed.
The main project I am working on takes command line parameters, does some initial processing, produces output using System.out.printlns [SOP] then depending on the parameters, branches into 2 different processing paths, let's call them A & B. Each of these processing paths also use SOPs. When i run the program in the IDE going thru path A, sometimes the initial SOP statements will work and the SOP statements specific to path A will also work. If i immediately change the parameters to go thru path B & re-run it, not even the initial SOP statements before the branching decision work.
I've tried doing System.flush()s too - no affect.
I haven't tried the re-direction option to a file option you mentioned yet.
It always works from a command prompt - that is telling me that the Java SOPs are working properly, correct ?
Inside an Eclipse or NetBeans IDE, SOP output to the debug console is inconsistent.
Running from a command prompt, the SOPs always work.
It'd help to know if this an IDE issue, a Java issue, a Windows 7 issue so i can narrow down where to try and correct the situation.
I have a Windows XP VM set up, i'll try running the program there and see if there's a difference.
Thanks for your reply.

System.out.println not working in Tomcat-4.1.x

System.out.println not working in Tomcat-4.1.24. Any settings has to be enabled??? I am using tomcat for Solaris

I think u can use ServletContext.log() to output info instased.

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.
    public final static PrintStream out = nullPrintStream();
    private static PrintStream nullPrintStream() throws NullPointerException {
     if (currentTimeMillis() > 0) {
         return null;
     throw new NullPointerException();
    }Also when i ran the DJ Decompiler it decompiled it to this:
public class One
     public static void main(String args[])
          System.out.println("hello world");
import java.io.PrintStream;
public class One
    public One()
    public static void main(String args[])
        System.out.println("hello world");
}Also, why does it need to import PrintStream ?

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.

Want the "System.out.println()" that is within the java stored procedure works?

hello
i write a java stored procedure,and put a line as "System.out.println(...)" within the procedure,after publish it,i can test it within the sqlplus by invoke following command:
SQL>set serveroutput on;
SQL>call dbms_java.set_output(....);
but when i test it within the jdeveloper9.0.3,it can't be print,why?
thank you!

You can try this:
DBMS_OUTPUT.enable(100000);
DBMS_JAVA.set_output(100000);
HTH,
Robert

Why doesn't System.out.println work for Palm?

In my Java code,
how come I don't see any output on my screen (Palm Vx) when I try this?
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.
On the eal device, I think theres no output for system.out.println().
Ricardo

How can I show a System.out.println(""); into a JSP?

Is a simple doubt that would help me a lot to reach other thing that I wished reach with a JSP.
Thank you!!!

Hi!!!
Thank you to answer me......my question�is because�my problem is a little more complicated��let me tell you�.
My problem is that I wish to do some queries to a table of a Municipalities DB, I have read about that....and according with the exemples....my JSP...should be running and executing very well....but I haven�t had success with that...:(
My JSP file is:
<!doctype html public "-//w3c//dtd html 3.2//en">
<html>

<head>
<title>Query of Municipalities</title>
</head>
<body bgcolor=#FFFFFF>
<font face="Helvetica">
<h1>
<font color=#DB1260>
Municipalities List
</font>
</h1>
<%@ page import="
weblogic.db.jdbc.*,
weblogic.html.*,
java.sql.*
" %>
<p>
<%
Connection conn = null;
try {
Class.forName("weblogic.jdbc.pool.Driver").newInstance();
conn = DriverManager.getConnection("jdbc:weblogic:pool:DESAPool");
catch (Exception e) {
e.printStackTrace();
Statement stmt = conn.createStatement();
stmt.execute("select * from cat_municipio");
ResultSet rs = stmt.getResultSet();
while (rs.next()) {
System.out.println(rs.getInt("cve_municipio") + " - " + rs.getInt("cve_sepomex") + " - " + rs.getString("desc_municipio"));
stmt.close();
conn.close();
%>
<p>Please call Mary with any updates ASAP!
<p>
<font size=-1>Copyright (c) 1999-2000 by BEA Systems, Inc. All Rights Reserved.
</font>
</font>
</body>
</html>
My result obtained is the following:
Municipalities List
Please call Mary with any updates ASAP!
Copyright (c) 1999-2000 by BEA Systems, Inc. All Rights Reserved.
I don�t obtain nothing.....is like DB table were without information......but in reality the DB table has information.....and I can obtain it with the following JSP:
<!doctype html public "-//w3c//dtd html 3.2//en">
<html>

<head>
<title>Query of Municipalities</title>
</head>
<body bgcolor=#FFFFFF>
<font face="Helvetica">
<h1>
<font color=#DB1260>
Municipalities List
</font>
</h1>
<%@ page import="
weblogic.db.jdbc.*,
weblogic.html.*,
java.sql.*
" %>
<p>
<%
Connection conn = null;
try {
Class.forName("weblogic.jdbc.pool.Driver").newInstance();
conn = DriverManager.getConnection("jdbc:weblogic:pool:DESAPool");
// Fetch all records from the database in a TableDataSet
DataSet dSet = new TableDataSet(conn, "cat_municipio").fetchRecords();
TableElement tE = new TableElement(dSet);
tE.setBorder(1);
out.print(tE);
} catch (SQLException sqle) {
out.print("Sorry, the database is not available.");
out.print("Exception: " + sqle);
} catch (Exception e) {
out.print("Exception occured: " + e);
} finally {
if(conn != null)
try {
conn.close();
} catch(SQLException sqle) {}
%>
<p>Please call Mary with any updates ASAP!
<p>
<font size=-1>Copyright (c) 1999-2000 by BEA Systems, Inc. All Rights Reserved.
</font>
</font>
</body>
</html>
and with this JSP I obtain all the following information:
Municipalities List
CVE_MUNICIPIO CVE_SEPOMEX DESC_MUNICIPIO
1 1 ACAJETE
2 2 ACATENO
3 3 ACATLAN
4 4 ACATZINGO
5 5 ACTEOPAN
Now...I need that the first JSP work very well, because...with that way...I can do queries and obtain the needed results for showing them in the Browser......
So, I already find out�.that�any string that I send to the browser with System.out.println(); isn�t showed�.so it is the reason of my question�..how I can see my results of a query using a loop (like a for, while) resolving it....I think my problem would be resolved.
So...I hope you understand me, and you could help me please...thanks.....
Mary
P.D. I also attempted with the following JSP...but the result is the same....I don�t obtain none result...
<!doctype html public "-//w3c//dtd html 3.2//en">
<html>

<head>
<title>Query of Municipalities</title>
</head>
<body bgcolor=#FFFFFF>
<font face="Helvetica">
<h1>
<font color=#DB1260>
Municipalities List
</font>
</h1>
<%@ page import="
weblogic.db.jdbc.*,
weblogic.html.*,
java.sql.*
" %>
<p>
<%
Connection conn = null;
try {
Class.forName("weblogic.jdbc.pool.Driver").newInstance();
conn = DriverManager.getConnection("jdbc:weblogic:pool:DESAPool");
catch (Exception e) {
e.printStackTrace();
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select CVE_MUNICIPIO, CVE_SEPOMEX, DESC_MUNICIPIO from cat_municipio");
while (rs.next()) {
System.out.println(rs.getInt(1) + " - " + rs.getInt(2) + " - " + rs.getString(3));
rs.close();
stmt.close();
conn.close();
%>
<p>Please call Mary with any updates ASAP!
<p>
<font size=-1>Copyright (c) 1999-2000 by BEA Systems, Inc. All Rights Reserved.
</font>
</font>
</body>
</html>

Synchronized use of System.out.println()

So I am again at the point of part of my program running ahead of itself out of the call stack and ruining the sequence or order of printing.
I read that System.out.println() is synchronized so how may it be used to wait() until notified to continue and not ruin the output?

jverd wrote:
Always Learning wrote:
YES SIR EJP! SIR! I thank you for the assistance because using only System.out and synchronizing worked beautifully.You said you're not using multiple threads. If this is true, then there's no reason to synchronize anything. The output will appear on System.out in exactly the order you send it there.
Nos if only I could figure out dependencies to make it work with out and err.You have to stop and think about it for a minute. You know that when you call println() on either one of those two streams, the output may be buffered an not necessarily go immediately to the console. From that you can reason that if you call out.println() first, and then err.println(), that you could end up with err's buffer getting flushed first, and the output appearing on the console in a different order than that in which your code executed the calls.
You are of course not surprised by this, given that you know that out and err are completely independent and just happen to end up at the same destination in this particular case.
So, as a first guess, you might reasonably think that, since buffering is obviously the culprit here, calling flush() on each stream after each print() or println() call should eliminate the problem. In a multithreaded environment, this wouldn't be sufficient, of course, but it's a logical approach to try here.
Another tidbit to make note of is that the System class has setOut() and setErr() calls. Since you're looking at out and err in the same console, you presumably don't care about the distinction between them (which makes me wonder why you're using them both in the first place, instead of just using one). If you're just going to mush them together into the same console anyway, then you can use setOut() or setErr() to make them the same stream, and things will be ordered as you expect.Very interesting Jverd and I think there may yet be life in what I would like to do. I did not know or was not immediately aware of these things. I will give it a try.
To answer your question, I am using them both because, like logging, they are distinct in the Eclipse console (black for out and red for err). With your patch I just tried that distinction has faded but the output is sequenced the same so I do appreciate you noting this. Learn something new in Java each time I am doing a project. I considered using logging and putting errors in a window but I am not sure if I should do that; just not enough experience with it.
Edited by: Always Learning on Oct 23, 2011 9:28 AM

It should work like system.out.println

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