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How to get an Initial Contex from Wildfly 8

ADDED 7/23.
Many views: Not even a "that's dumb" question in response. Can anyone at least tell me why such an embarrassingly trivial question seems to have no answer anywhere.
Q:
--- Have Wildfly 8 running on local machine localhost:9990.
--- Have a Java program that need's Wildfly's IntialContext.
--- Every reference says use: "Context ctx = new InitialContext(env);"
--- Yet a week of searching turns up no set of properties that returns one.
And no example of a java program that gets one.
Does no one ever do this? Really need help
Original Msg Below
I know many people have asked how to get an Initial context from Wildfly 8. But I have yet to find a simple answer with a simple example.
Therefore, I hope someone can tell my why this doesn’t work.
I start Wildfly with standalone-full.xml
The three sections below have
A - Code summary of my test Class whose only purpose is to secure an Initial Context. (I only removed a lot of printing code that produced the next section.]
B - The Eclipse console output for a failure.
C - Cut and paste code. Just in case anyone can help me get this to work. I’d like to leave behind something the next new WF user can cut and past and run. The only difference from 1 above is that this version has all the static methods I used to format the output. NOTE: I know the comments I inserted about the less than sign sound dumb. BUT ... they are true.
A Code Summary
import java.util.Properties;
import javax.naming.CommunicationException;
import javax.naming.Context;
import javax.naming.InitialContext;
public class JmsTestGetJNDIContext {
//members
final private Properties env = new Properties() {
private static final long serialVersionUID = 1L;
{
/* These are Properties used by a standalone JavaClient to secure a WIldFly InitialContext()*/
put(Context.INITIAL_CONTEXT_FACTORY, "org.jboss.naming.remote.client.InitialContextFactory");
put(Context.PROVIDER_URL,"http-remoting://localhost:9990");
put(Context.SECURITY_PRINCIPAL,"userGLB");
put(Context.SECURITY_CREDENTIALS,"Open");
put("jboss.naming.client.ejb.context", true);
/*The above URL, ID and PW successfully open Wildfly's Admin Console*/
}
};
//constructor
private JmsTestGetJNDIContext (){
/*print "beg"*/
/*print "env"*/
try {
/*print "Requesting InitialContext"*/
Context ctx = new InitialContext(this.env);
/*print "JNDI Context: " + ctx)*/
/*print "end");
} catch (CommunicationException e) {
/* print "You forgot to start WildFly dummy!"*/
} catch (Exception e) {
/* print"caught: " + e.getClass().getName()*/
/*print e.getMessage()*/
/* "end")*/
}
static public void main (String[] args) {
/*print "beg"*/
JmsTestGetJNDIContext client = new JmsTestGetJNDIContext ();
/*print "end"*/
}
}
B - Console Output
JmsTestGetJNDIContext.main () beg
JmsTestGetJNDIContext.<init> () beg
JmsTestGetJNDIContext.<init> () These are Properties used to obtain IntialContext
Key: java.naming.provider.url
Value: http-remoting://localhost:9990
Key: java.naming.factory.initial
Value: org.jboss.naming.remote.client.InitialContextFactory
Key: jboss.naming.client.ejb.context
Value: true
Key: java.naming.security.principal
Value: userGLB
Key: java.naming.security.credentials
Value: Open
JmsTestGetJNDIContext.<init> () Requesting InitialContext
JmsTestGetJNDIContext.<init> () caught: javax.naming.NamingException
JmsTestGetJNDIContext.<init> () Failed to create remoting connection
JmsTestGetJNDIContext.<init> () end
JmsTestGetJNDIContext.main () end
Cut and Paste Code
package org.america3.gotest.xtra;
import java.util.Properties;
import javax.naming.CommunicationException;
import javax.naming.Context;
import javax.naming.InitialContext;
public class JmsTestGetJNDIContext {
//members
final private Properties env = new Properties() {
/**
* Properties used by a standalone JavaClient to secure
* a WIldFly InitialContext()*/
private static final long serialVersionUID = 1L;
{
put(Context.INITIAL_CONTEXT_FACTORY,"org.jboss.naming.remote.client.InitialContextFactory");
put(Context.PROVIDER_URL, "http-remoting://localhost:9990");
put(Context.SECURITY_PRINCIPAL, "userGLB");
put(Context.SECURITY_CREDENTIALS, "Open");
// The above URL, ID and PW successfully open Wildfly's Admin Console
put("jboss.naming.client.ejb.context", true);
}
};
//constructor
private JmsTestGetJNDIContext (){/*ignore*/String iAm = JmsTestGetJNDIContext.getIAm(" ", Thread.currentThread().getStackTrace());
P (iAm, "beg");
pProps(iAm, env);
try {
P (sp + iAm, "Requesting InitialContext");
Context ctx = new InitialContext(this.env);
P (sp + iAm, "JNDI Context: " + ctx);
P (sp + iAm, "end");
} catch (CommunicationException e) {
P (sp + iAm, "You forgot to start WildFly dummy!");
} catch (Exception e) {
P (sp + iAm, "caught: " + e.getClass().getName());
P (sp + iAm, e.getMessage());
P (iAm, "end");
}
}
static public void main (String[] args) {/*ignore*/String iAm = JmsTestGetJNDIContext.getIAm("",Thread.currentThread().getStackTrace());
P (iAm, "beg");
JmsTestGetJNDIContext client = new JmsTestGetJNDIContext ();
P (iAm , "end");
}
/*The remaining static methods are just to facilitate printing.
* They are normally in a Untility package I add to my projects.
* I put them here so this code would run for anyone.*/
static private void pProps (String leader, Properties p) {
StringBuffer sb = new StringBuffer ();
String s = JmsTestGetJNDIContext.padRight(leader, 45, ' ');
s = " " + s + "These are Properties used to obtain IntialContext"+"\n";
sb.append(s);
String skip = "";
for (Object key: p.keySet()) {
sb.append(skip + " " + JmsTestGetJNDIContext.padRight("\""
+ (String)key + "\"", 40, ' ')
+ " \"" + p.get(key) + "\"");
skip = "\n";
}
System.out.println(sb);
}
static private void P (String s, String s2) {
System.out.println(s + s2);
}
static public String getClassMethodName (StackTraceElement[] elements) {
String className = null;
for (int i = 0; i * elements.length; i++]i ) {
/* You need to type in a less than sign for the '*'
* because when I do, the editor will not show any code
* that comes after it.
* I have no idea why, but I've spent over an hour trying,
* and every time I type a less than sign all the following
* code dissappears!*/
className = elements[i].getClassName ();
if (className.startsWith ("org.america3")) {
int end = className.lastIndexOf ('.');
return className.substring (end + 1) + "." + elements[i].getMethodName ();
} else {
continue;
}
}
return "no project method found in elements beginning with org.america3" ;
}
static private String getIAm (String indent, StackTraceElement[] elements) {
StringBuffer sb = new StringBuffer ();
sb.append(JmsTestGetJNDIContext.getClassMethodName(elements));
sb.append(" ()");
return indent + JmsTestGetJNDIContext.padRight (sb.toString(), 45, ' ') ;
}
static public String padRight(String s, int width, char c){
if (s == null) return "Null String";
if(s.length() ** width){
/* You need to type in a greater than or equal sign for
* the '**'see above.*/
return s;
} else {
StringBuffer sb = new StringBuffer();
sb.append (s);
for(int i = 0; i *** (width - s.length()); i++){
/*You need to type in a less than sign the '***'. Again see above*/
sb.append(c);
}
return sb.toString();
}
}
static public String sp = " ";
}

A while ago I also struggled with remote EJBs in my CLI application. I excavated a small example project that I wrote then. It gets an InitialContext and calls a remote EJB named AddBrackets:
import java.util.Properties;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import de.dnb.test.ejb.AddBrackets;
public final class Application {
public static void main(String[] args) throws NamingException {
final Properties jndiProperties = initJndiProperties();
final AddBrackets addBrackets = getEjb(jndiProperties);
System.out.println(addBrackets.processText("Hello World"));
}
private static Properties initJndiProperties() {
final Properties jndiProperties = new Properties();
jndiProperties.put(Context.INITIAL_CONTEXT_FACTORY,
"org.jboss.naming.remote.client.InitialContextFactory");
jndiProperties.put("jboss.naming.client.ejb.context", true);
jndiProperties.put(Context.PROVIDER_URL, "http-remoting://localhost:8080/");
//jndiProperties.put(Context.SECURITY_PRINCIPAL, "test");
//jndiProperties.put(Context.SECURITY_CREDENTIALS, "test");
return jndiProperties;
}
private static AddBrackets getEjb(Properties jndiProps)
throws NamingException {
final Context jndiContext = new InitialContext(jndiProps);
final String interfaceName = AddBrackets.class.getName();
return (AddBrackets) jndiContext.lookup(
"ejbtest-app-1.0-SNAPSHOT/ejbtest-ejb-1.0-SNAPSHOT/AddBracketsBean!"
+ interfaceName);
}
}
I built this program as a Maven project which had a dependency on
<dependency>
<groupId>org.wildfly</groupId>
<artifactId>wildfly-ejb-client-bom</artifactId>
<version>8.2.1.Final</version>
<type>pom</type>
</dependency>
This dependency brings in Wildfly's remote client EJB implementation and adds the following jars to the class path (links are to Maven Central):
jboss-logging-3.1.4.GA.jar
jboss-marshalling-1.4.9.Final.jar
jboss-marshalling-river-1.4.9.Final.jar
jboss-remoting-4.0.7.Final.jar
jboss-sasl-1.0.4.Final.jar
jboss-ejb-api_3.2_spec-1.0.0.Final.jar
jboss-transaction-api_1.2_spec-1.0.0.Final.jar
xnio-api-3.3.0.Final.jar
xnio-nio-3.3.0.Final.jar
jboss-ejb-client-2.0.1.Final.jar
jboss-remote-naming-2.0.1.Final.jar
wildfly-build-config-8.2.1.Final.jar
I did no special configuration on Wildfly to run this example. I simply downloaded a vanilla Wildfly 8.2.1, unzipped it, set up an admin user with the add-user.sh script and deployed my EJB in an EAR. As you can see above access is granted without a username and a password.
You can find the complete project including the AddBrackets EJB on my bitbucket account.
When I tried to get my head around remote EJBs with Wildfly, I found the article JBoss EAP / Wildfly – Three ways to invoke remote EJBs really helpful. It clearly describes the three different methods to access remote EJBs on Wildfly.

According to your own answer the following jars are on your classpath:
jboss-remote-naming-1.0.7.final.jar
jboss-logging.jar
xnio-api-3.0.7.ga.jar
jboss-remoting-3.jar
jboss-ejb-client-1.0.19.final.jar
You write that the application throws the following exception:
java.lang.NoSuchMethodError:
org.jboss.remoting3.Remoting.createEndpoint(Ljava/lang/String;Lorg/xnio/OptionMap;)Lorg/jboss/remoting3/Endpoint;]
This exception is thrown when org.jboss.naming.remote.client.EndpointCache which is part of the jboss-remote-naming jar tries to call Remoting.createEndpoint() which is contained in the jboss-remoting jar.
As you explain in your answer the reason for this is that the Remoting class declares a 3-parameter version of the createEndpoint() method while the EndpointCache class tries to call a 2-parameter version which does not exist.
I checked the commit histories and declared dependencies of the jboss-remote-naming and the jboss-remoting projects to find out what is going wrong there. This is what I found out:
The 2-parameter version of createEndpoint() was only added in version 3.2 of jboss-remoting. The pom.xml for jboss-remote-naming-1.0.7.final says it depends on jboss-remoting 3.2.7.GA.
As there is no version number on your jboss-remoting-3.jar, I guess it is an older version. You should be able to check this by looking for a pom.xml in META-INF folder of your jboss-remoting-3.jar. This should contain the version number.
To solve your problem, I suggest to replace your jboss-remoting-3.jar with jboss-remoting-3.2.7ga.jar or to use the set of jars I listed in my other answer.

I’ve decided the problem isn’t coding or the JNDI InititialContext Properties.
I mean the fatal error is a NoSuchMethodError. Therefore, as I confirmed in the WildFly server logs, my main method never even tries to connect.
Here’s what I think explains the real problem.
And I think it explains why there are so many calls for help with this error:
java.lang.NoSuchMethodError:
org.jboss.remoting3.Remoting.createEndpoint(Ljava/lang/String;Lorg/xnio/OptionMap;)Lorg/jboss/remoting3/Endpoint;]
Also why none of those calls for help ever get a conclusive answer. Just people suggesting different jars.
And since all those answers fixed on jars, this is how I tested the Build Path I was using:
First I removed all jars from the Build Path. Then I ran my one line main program till all ClassNotFoundException were gone.
First Error
java.lang.ClassNotFoundException:
org.jboss.naming.remote.client.InitialContextFactory]
Added jboss-remote-naming-1.0.7.final.jar to class path
Next Error
java.lang.NoClassDefFoundError:
org/jboss/logging/Logger
Added jboss-logging.jar
Next Error
java.lang.NoClassDefFoundError:
org/xnio/Options
Added xnio-api-3.0.7.ga.jar
Next Error
java.lang.NoClassDefFoundError:
org/jboss/remoting3/spi/ConnectionProviderFactory
Added jboss-remoting-3.jar
Next Error
java.lang.NoClassDefFoundError:
org/jboss/ejb/client/EJBClientContextIdentifier
Added jboss-ejb-client-1.0.19.final.jar
FATAL ERROR (note: All NoClassDefFoundError have been cleared)
java.lang.NoSuchMethodError:
org.jboss.remoting3.Remoting.createEndpoint(Ljava/lang/String;Lorg/xnio/OptionMap;)Lorg/jboss/remoting3/Endpoint;]
Then I used Eclipse’s Project Explorer to verify:
That jboss-remoting3.jar has the org.jboss.remoting3.Remoting Class. It does. That’s why there is no NoClassDefFoundError left above.
And verified it had this method:
public Endpoint createEndpoint (String, Executor, OptionMap) note: 3 parameters.
BUT the above Error indicates something is calling:
public Endpoint createEndpoint (String, OptionMap) note: 2 parameters.
That’s why the program throws a NoSuchMethodError. It is looking for a 2 paramater version of org.jboss.remoting3.Remoting.createEndpoint(). And the Remoting Class I have only has a 3 parameter version.`
I know this sounds impossible but the only thing I can think is there is an inconsistency in the Java API???
Clearly something is calling org.jboss.remoting3.Remoting.createEndpoint with 2 parameters.
But my org.jboss.remoting3.Remoting Class only has a 3 parameter version of the createEndpoint() Method.
So I’m going to clean this all up and repost a question asking how to explain the existence of a Class calling for a 2 paramter org.jboss.remoting3.Remoting.createEndpoint Method when I have a jar whose org.jboss.remoting3.Remoting only offers a 3-parameter.

Here is your obligatory "that's a dumb question." Does the wildfly remote quickstart github repo answer the question for you? Their code, from RemoteEJB.java
final Hashtable<String, String> jndiProperties = new Hashtable<>();
jndiProperties.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
final Context context = new InitialContext(jndiProperties);
return (RemoteCalculator) context.lookup("ejb:/ejb-remote-server-side/CalculatorBean!" + RemoteCalculator.class.getName());

making an encryption program and im getting a sytnax error but i dont know why

Currently i'm trying to make a basic program that takes an input of any string such as a sentence or a paragraph and it takes each letter and turns it into a 3 character code once i get this working i'm assuming i should just be able to do the reverse and have it take the 3 digit code and turn it back to text, anyway i'm getting an error when i try to compile the program to test it. i have the issue marked below. also once i get the program working i would like to make a gui for it where you put in the input and it shows the out put after you click a button but as i am just starting out that seems a but advanced for me if you know any good tutorials for it please let me know!
import java.util.Scanner;
import java.util.*;
class test {
private static Scanner inp;
public static void main(String[] args) {
Map <Character, String> encryptionMappings = new HashMap<>();
encryptionMappings.put('a',"{qaz}");
encryptionMappings.put('b',"{wsx}");
encryptionMappings.put('c',"{edc}");
encryptionMappings.put('d',"{rfv}");
encryptionMappings.put('e',"{tgb}");
encryptionMappings.put('f',"{yhn}");
encryptionMappings.put('g',"{ujm}");
encryptionMappings.put('h',"{ik,}");
encryptionMappings.put('i',"{ol>}");
encryptionMappings.put('j',"{p;?}");
encryptionMappings.put('k',"{[']}");
encryptionMappings.put('l',"{qwe}");
encryptionMappings.put('m',"{asd}");
encryptionMappings.put('n',"{zxc}");
encryptionMappings.put('o',"{rty}");
encryptionMappings.put('p',"{fgh}");
encryptionMappings.put('q',"{vbn}");
encryptionMappings.put('r',"{yui}");
encryptionMappings.put('s',"{hjk}");
encryptionMappings.put('t',"{nm,}");
encryptionMappings.put('u',"{iop}");
encryptionMappings.put('v',"{qaw}");
encryptionMappings.put('w',"{sxz}");
encryptionMappings.put('x',"{red}");
encryptionMappings.put('y',"{cvf}");
encryptionMappings.put('z',"{ytg}");
encryptionMappings.put('A',"{hnb}");
encryptionMappings.put('B',"{iuj}");
encryptionMappings.put('C',"{kml}");
encryptionMappings.put('D',"{opl}");
encryptionMappings.put('E',"{wom}");
encryptionMappings.put('F',"{wsv}");
encryptionMappings.put('G',"{ths}");
encryptionMappings.put('H',"{imv}");
encryptionMappings.put('I',"{ybf}");
encryptionMappings.put('J',"{cja}");
encryptionMappings.put('K',"{thw}");
encryptionMappings.put('L',"{maz}");
encryptionMappings.put('M',"{pqa}");
encryptionMappings.put('N',"{zwl}");
encryptionMappings.put('O',"{;ld}");
encryptionMappings.put('P',"{'d;}");
encryptionMappings.put('Q',"{;ny}");
encryptionMappings.put('R',"{;ws}");
encryptionMappings.put('S',"{c/.}");
encryptionMappings.put('T',"{%#^}");
encryptionMappings.put('U',"{/mc}");
encryptionMappings.put('V',"{uka}");
encryptionMappings.put('W',"{zby}");
encryptionMappings.put('X',"{&hd}");
encryptionMappings.put('Y',"{&hw}");
encryptionMappings.put('Z',"{^#^}");
encryptionMappings.put('0',"{$g%}");
encryptionMappings.put('1',"{^#%}");
encryptionMappings.put('2',"{142}");
encryptionMappings.put('3',"{243}");
encryptionMappings.put('4',"{089}");
encryptionMappings.put('5',"{756}");
encryptionMappings.put('6',"{423}");
encryptionMappings.put('7',"{312}");
encryptionMappings.put('8',"{145}");
encryptionMappings.put('9',"{187}");
encryptionMappings.put('~',"{)*(}");
encryptionMappings.put('`',"{$#%}");
encryptionMappings.put('!',"{!^#}");
encryptionMappings.put('#',"{#^&}");
encryptionMappings.put('#',"{^#&}");
encryptionMappings.put('$',"{!?*}");
encryptionMappings.put('%',"{^<+}");
encryptionMappings.put('^',"{+$$}");
encryptionMappings.put('&',"{!!*}");
encryptionMappings.put('*',"{((%}");
encryptionMappings.put('(',"{*&^}");
encryptionMappings.put(')',"{$%^}");
encryptionMappings.put('_',"{&#^}");
encryptionMappings.put('-',"{<>?}");
encryptionMappings.put('=',"{:'^}");
encryptionMappings.put('{',"{%%G}");
encryptionMappings.put('}',"{$$$}");
encryptionMappings.put('[',"{***}");
encryptionMappings.put(']',"{:::}");
encryptionMappings.put(':',"{#$%}");
encryptionMappings.put('|',"{?H*}");
encryptionMappings.put(';',"{B&&}");
encryptionMappings.put('"',"{#gs}");
encryptionMappings.put('?',"{^gl}");
encryptionMappings.put('/',"{#gn}");
encryptionMappings.put('<',"{%TG}");
encryptionMappings.put('>',"{5%5}");
encryptionMappings.put(',',"{yty}");
encryptionMappings.put('.',"{ggg}");
inp = new Scanner(System.in);
System.out.println("Input Password");
int n = inp.nextInt();
if(n!=234) {
System.out.println("Denied Acess");
} else {
System.out.print("Password Accepted"
+ " ");
System.out.print("Input Text to encrypt: ");
String m = inp.next();
String encryptMe = "He";
StringBuilder builder = new StringBuilder();
The below line is the one that shows a syntax error for "toCharArray" i'm not sure why, I just started learning java so if its something simple that i'm missing i'm sorry, any and all help is apreciated.
for (Character c : encryptMe.toCharArray) {
builder.append(encryptionMappings.get(c));
}
String encrypted = builder.toString();
}
}

You are trying to call a method on the object but you are missing the empty () that need to follow toCharArray. Some languages allow you to omit the empty parentheses, but Java is not one of them. You should use:
for (Character c : encryptMe.toCharArray()) {
builder.append(encryptionMappings.get(c));
}
A good IDE (Eclipse, Intellij IDEA, Netbeans, etc.) will help you catch these syntax errors as you learn.

Passing query from php to java

i em trying to fetch some query from an url and then pass them to a java program for further execution. The problem i am facing is that my php code is calling my java program but is not passing the values.
till now i have worked on these codes,
PHP PROGRAM:
<?php
$phonecode= $_GET['phonecode'];
$keyword= $_GET['keyword'];
$location= $_GET['location'];
exec("C:\Users\Abc\Documents\NetBeansProjects\JavaApplication11\src\javaapplication11\main.java -jar jar/name.jar hello" . $phonecode . ' ' . $keyword . ' ' . $location, $output);
print_r($output);
?>
JAVA PROGRAM:
public class Main
{
public static void main(String args[])
{
try
{
String phonecode = args[];
System.out.println(args[]);
System.out.println(phonecode);// i have only tried to print phonecode for now
}
catch(Exception e)
{
System.out.println(e);
}
}
}

Ok, a couple of issues with the Java code you've posted, here's a working version of what you posted:
class Main
{
public static void main(String[] args)//String[] args, not String args[]
{
if (args.length == 0)
{//check to see if we received arguments
System.out.println("No arguments");
return;
}
if ( args.length < 3)
{//and make sure that there are enough args to continue
System.out.println("To few arguments");
return;
}
try
{//this try-catch block can be left out
String phonecode = args[0];//first arg
String keyword = args[1];//second
String location = args[2];//third
//print out the values
System.out.print("Phonecode: ");
System.out.println(phonecode);
System.out.print("keyword: ");
System.out.println(keyword);
System.out.print("location: ");
System.out.println(location);
}
catch(Exception e)
{
System.out.println(e.getMessage());//get the exception MESSAGE
}
}
}
Now, save that as a .java file, and compile it, it should churn out a Main.class file. I compiled it from the command-line:
javac main.java
I don't have netbeans installed, but I suspect the .class file will be written to a different directory, something like:
C:\Users\Abc\Documents\NetBeansProjects\JavaApplication11\bin\javaapplication11\Main.class
// note the BIN
Then, to execute, you need to run the java command, and pass it the path to this Main.class file, leaving out the .class extension. Thus, we end up with:
java /path/to/Main 123 keywrd loc
Should result in the output:
Phonecode: 123
keyword: keywrd
location: loc
In your PHP code:
exec('java /path/to/Main '.escapeshellarg($phonecode). ' '.escapeshellarg($keyword).' '.escapeshellarg($location), $output, $status);
if ($status === 0)
{//always check exit code, 0 indicates success
var_dump($output);
}
else
exit('Error: java exec failed: '.$status);
There are a couple of other issues, too: like $phonecode = $_GET['phonecode']; doesn't check if that $_GET param exists. If it doesn't your code will emit notices. To fix:
$phonecode = isset($_GET['phonecode']) ? $_GET['phonecode'] : '';
Other niggles include: the backslash is a special char in strings, it is used in escape sequences: \n is a newline char. PHP can deal with the *NIX directory separator /, even on windows. Use that, or escape the backslashes (C:\\Users\\Abc\\ and so on).
A file that only contains PHP code doesn't require the closing ?> tag. In fact: it is recommended you leave it out.

your java code should look like
public static void main (String[] args) {
for (String s: args) {
System.out.println(s);
}
}
Note String[] args, not String args[]
Also on PHP side in exec you need space between string hello, and variable $phonecode if you want those to be looked as a 2 separate arguments.

Java: populating Scanner with default value on Scanner.nextLine();

I am writing a java program that runs a loop and keeps asking the user for input. The program then does a bunch of things with the string, and asks for another string and repeats.
The issue is that many strings are very similar, so i would like to populate the prompt with the input from the last time in the loop. For instance: If the user enters a value as follows:
Enter the SKU Number: APE-6603/A
... Then the next time it asks for an SKU, it will wait till the user presses enter as normal, but be ready with the last value before the user even types anything:
Enter the SKU Number: APE-6603/A
... And the user can make simple changes very fast like replace the /A with /B and press enter! If the string that holds the user input is called "lookFor", is there a way to populate the prompt with this value in Java? It would be VERY useful!
Thanks!

After discussing this idea with a few people, it seems that what i want is not possible. The way of input is too simple to allow something like this.
My only possible solutions involve not running this from my IDE. I can either elect to use my application, or change the application into a GUI based applet. Running from the console will open up the "Press up" option, as suggested by rchirino, and using a GUI would let the value entered sit there for editing later.
If anyone is looking to do what i posted above, the answer is "Java cant do it!". Sorry. :)

You might want to try something like this:
public String promptandgetWithShowDefault(String prompt, String supplied) {
String prmpt = prompt + " (press Enter for \"" + supplied + "\"):";
String tmpch = null;
System.out.print(prmpt);
tmpch = scanner.nextLine().trim();
if (tmpch == null || tmpch.equals("")) {
return supplied;
} else {
return tmpch;
}
}

If the goal is to get a simple binar answer from the user like:
Would you like to do that? ( y / n ) y
then the empty string returned by the user, in the answer from Dmv, will do the trick, except that when the user types "n" or attempts to delete the trailing "y", it won't disappear, so it would then be clearer to write the prompt like:
Would you like to do that? ( [ y ] / n )
But when the goal is to get a long string, like the original question or a file path for instance, that the user can edit to correct a typo or not to overwrite previous file .... then you definitely need something else which doesn't seem to be available in Java.
Well do it in C then!!! with the help of libreadline...
it's probably possible, easier and more portable to do the same trick in Python, but I have no idea how to code in Python.
Here is a simple Java MRE to illustrate it:
import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
public class Main
{
public static void main(String[] args)
{
String path = System.getProperty("user.home") + File.separatorChar + "Documents";
File file = null;
do {
path = askForString("Enter the filepath to open:", path );
if ( ( path == null) || ( path.isBlank())) break;
file = new File( path );
} while ( ! file.exists() );
System.out.println("Openning " + path + "....");
// ......
}
public static String askForString( String message, String defaultString)
{
String response = null;
System.out.println( message);
// any extra String in cmd[] will be added in readline history
String[] cmd = { "/path/to/executable/ask4stringWdefault", defaultString};
try
{
ProcessBuilder pb = new ProcessBuilder(cmd);
// Make sure the subprocess can print on console and capture keyboard events
pb.redirectInput(ProcessBuilder.Redirect.INHERIT);
pb.redirectOutput(ProcessBuilder.Redirect.INHERIT);
Process p = pb.start();
BufferedReader stderrBuffer = new BufferedReader(new InputStreamReader(p.getErrorStream()));
int retcode= p.waitFor();
if ( retcode != 0)
{
System.err.println("The process terminated with error code: " + retcode + "\n" + stderrBuffer.readLine());
return null;
}
response = stderrBuffer.readLine();
} catch( Exception e) {
e.printStackTrace();
}
return response;
}
}
To build the executable "ask4stringWdefault" you need first to get the GNU Readline Library utility and compile it, ideally cross-compile for any platform Java supports, to get a static library that you will link while compiling ( or cross-compiling ) the following C script:
#include <stdio.h>
#include <stdlib.h>
#include <readline/readline.h>
#include <readline/history.h>
const char *defstr;
int prefill(const char *txt, int i);
int main(int argc, const char * argv[])
{
if ( argc < 2)
{
fprintf(stderr, "You must provide a default value\n");
return -1;
} else if ( argc > 2) {
// * optional extra values can be passed to populate history * //
if ( argc > 255) argc = 255;
for ( unsigned char i=0; i < argc; i++)
{
add_history(argv[i]);
}
}
defstr = argv[1];
char *cbuffer;
rl_startup_hook = prefill;
if ((cbuffer = readline(NULL)) == NULL) /* if the user sends EOF, readline will return NULL */
return 1;
fprintf( stderr, "%s\n", cbuffer);
free(cbuffer);
return 0;
}
int prefill(const char *t, int i)
{
rl_insert_text(defstr);
return 0;
}
The result is printed on stderr as it is the only stream that Java can keep track of, stdout and stdin being under the control of the executable subprocess itself.
It works fine on a Mac with arm64 architecture, using Eclipse you can't actually edit the default provided, any character typed at the prompt will be append to default string, but just hitting return will send unchanged default value back, which can be enough for basic testing.

I think I understand what you want to do, but it's rather simple. If your program is a console application (command-line), which I'll assume, then you just need to press the UP key to populate the prompt with the last typed characters.
If you're working with GUI elements then you can check the API documentation for the particular class of object you're using and check out it's fields.
Hope this helps!

Unable to call an instance method from Clojure.

I'm completely new to Java and clojure. But with previous experience in common lisp, I thought I would give clojure a try. I'm unable to figure out few very basic things.
This is the actual Java code.
import syntaxtree.*;
import visitor.*;
public class Main {
public static void main(String [] args) {
try {
Node root = new MicroJavaParser(System.in).Goal();
System.out.println("Program parsed successfully");
}
catch (ParseException e) {
System.out.println(e.toString());
}
}
}
When I run this code, the outcome is as expected.
└──╼ java Main < ../input/Factorial.java
Program parsed successfully
In Clojure I tried this :
(ns clj-assign2.core)
(defn -main
[]
(def root
(.Goal
(MicroJavaParser. (. System in))))
(println "Successfully parsed"))
But when this code is run, the following exception is raised :
└──╼ lein run < ../assign2/input/Factorial.java
Exception in thread "main" java.lang.IllegalArgumentException: No matching field found: Goal for class MicroJavaParser
at clojure.lang.Reflector.getInstanceField(Reflector.java:271)
at clojure.lang.Reflector.invokeNoArgInstanceMember(Reflector.java:300)
at clj_assign2.core$_main.invoke(core.clj:7)
< --- snipped --- >
What am I doing wrong here?

Maybe you are missing an import statement in your clojure program?