I compiled a program with a JAR in the classpath. Also ran it with the JAR passed with classpath. For instance I used MySQL .jar.
So I feel it was required in both classpath. I have heard the Servlet API jar is also an example of what is needed at compile time.
During runtime, I need to load the JAR files and relevant config files( .cfg files and .properties file) into CLASSPATH and run a specific java program from one of the JAR which is available in CLASSPATH.
Any relevant Java API details or a sample java program to implement the above use case.
I am looking at JSP page, which has code line as follows
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<%@ taglib uri="http://jakarta.apache.org/struts/tags-bean" prefix="bean" %>
<%@ taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html" %>
<%@ taglib uri="http://jakarta.apache.org/struts/tags-logic" prefix="logic" %>
This taglib will have to be installed on local environment. How is it referred in jsp ? I dont see any code in jsp, which refers to the location of JSTL. So how does jsp invoke these tags ? Is it through classpath ?If its so , how is classpath set for JSTL ? Is it just as classpath is set for java ?
I am writing an Ant script using the javac command but the library I need is bundled in an ear file, how can I reference this jar in ear file without extracting the ear file.
View Replies View RelatedI'm trying to run an enterprise java application running glasssfish server from my university ( the open university, distance learning and i recommend it). I get the following error:
pre-init:
init-private:
init-userdir:
init-user:
init-project:
do-init:
post-init:
init-check:
init:
[code]...
The Java EE server classpath is not correctly set up - server home directory is missing.Either open the project in the IDE and assign the server or setup the server classpath manually.For example like this: ant -Dj2ee.server.home=<app_server_installation_directory> BUILD FAILED (total time: 0 seconds)
I am having an issue that I cannot seem to resolve with Ant deployments and my Classpath.
I have a module that is needed to run with Open Wonderland but for some reason when I run this particular module deployment it doesn't recognize part of the classpath.
On my server I have a class called JadeRunner.class and it is included in my classpath. I can verify but running the following code:
public class testClassPath{
public static void main(String args[]){
String classArg = args[0];
try{
Class testClass = Class.forName(classArg);
}catch(ClassNotFoundException e){
e.printStackTrace();
}
}
}
I just enter the name of the class as an argument and if I get no errors that it can find the class. This works if I enter it directly from the command line. However with my ant deployment I get a ClassNotFoundException for this class.
I run my ant deployment as root but I use the -E switch so it picks up my environment variables. The ant deployment finds all my other environment variables except this one.
I have some sample outputs:
$ java testClassPath org.jdesktop.wonderland.modules.mas.jade.weblib.JadeRunner (this give no output, so it finds the class)
$ sudo -E java testClassPath org.jdesktop.wonderland.modules.mas.jade.weblib.JadeRunner (again no output, so it finds the class)
$ sudo -E ant deploy
This gives ClassNotFoundException: org.jdesktop.wonderland.modules.mas.jade.weblib.JadeRunner
I need to start a new JVM. To do this my (production-) code pick a certain jar and starts a class in it. The name of this class is not fix. The picked jar has other jars in its Manifest class path section.
For my tests I want to replace my jars red from the main jar with the compile target folders of my Eclipse projects that make up my Application.
Getting that folders is quite easy because i configured the Starter project to depend on the other Projects of my app so that they are available via System.getProperty("java.class.path"). But eclipse creates absolute path in there. The result is that I cannot use the output of System.getProperty("java.class.path") as command line parameter, it's simply to long.
I tried to put the class path in a temporary jar file but it looks like that the jars class path is not added to the resulting class path when i is simply added as another classpath entry at command line. On the other hand I cannot run this temporary jar file via -jar option because the main class cannot be found if it is not located in the temporary jar...
Meanwhile I found that the main problem is not so much the other Projects but the 3rd party libs which eclipse refers them in their maven repository location. They blow up my classpath. I tried to convert their paths to relative but this didn't change that much...
So my question is:
1. is there a way to provide the classpath in a text file to java executable on command line?
2. is there a way to run a jar with the -jar option if the main class is outside the jar (but within the classpath in the jars manifest)?
3. is there any other way to solve my problem resulting from the limited command line length?
I don't understand the classpath requirements for facelets and CDI on glassfish. I'm using Netbeans, and have the following:
thufir@dur:~/NetBeansProjects/EntAppWeb$ jar -tf dist/EntAppWeb.ear
META-INF/
META-INF/MANIFEST.MF
lib/
EntAppWeb-ejb.jar
EntAppWeb-war.war
lib/javaee-api-7.0.jar
thufir@dur:~/NetBeansProjects/EntAppWeb$
when I look at javaee-api it has javax.enterprise.context.ApplicationScoped and javax.inject.Named which are the particular imports being used in the bean. The facelets part is working, the template navigates correctly. It deploys to Glassfish and runs, except...there's no output from the @Named bean:
package dur.beans;
import javax.enterprise.context.ApplicationScoped;
import javax.inject.Named;
@Named("nextClient")
@ApplicationScoped
public class NextClient implements NextClientLocal {
[code]...
Now it's working. I can't figure what I did for the life of me...that's the desired output, each time the page is accessed the counter increments.Now it works. Is this on the right track? Way off base? I have an entity class from a database which I'd like to link up to this, and output the class.I can inject the entity into NextClient? I'm trying to do the "R" for Read in a CRUD application with CDI and facelets (using templates).
I've found much reference material on EJB, but it seems a mishmash. I just want to use CDI. What am I doing right/wrong, or, besides the PDF from Oracle on Java EE 7, what are good CDI reference material's?
This the output of java from my PC under linux platform (rhel 6.5).
[pentaho@vertica-srv1 Downloads]$ java -version
java version "1.7.0_79"
Java(TM) SE Runtime Environment (build 1.7.0_79-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.79-b02, mixed mode)
[Code] ....
But the problem is while trying to open ETL program under linux platform [pentaho@vertica-srv1 data-integration]$ ./spoon.sh .... I received the following error messages.
[pentaho@vertica-srv1 data-integration]$ ./spoon.sh
Trying to add database driver (JDBC): RmiJdbc.RJDriver - Warning, not in CLASSPATH?
Trying to add database driver (JDBC): jdbc.idbDriver - Warning, not in CLASSPATH?
Trying to add database driver (JDBC): org.gjt.mm.mysql.Driver - Warning, not in CLASSPATH?
Trying to add database driver (JDBC): com.mckoi.JDBCDriver - Warning, not in CLASSPATH?
[KnowledgeFlow] Loading properties and plugins...
I'm trying to add a CLASSPATH to a manifest file linking (not sure If that's the right word) to an sqljdbc4.jar file.
If I copy the file Into my root folder and use CLASSPATH: sqljdbc4.jar It works fine.
Class-Path: sqljdbc4.jar
Main-Class: com.ncntech.go
If I try CLASSPATH: C:Program FilesMicrosoft JDBC Driver 4.0 for SQL Serversqljdbc_4.0enusqljdbc4.jar I receive a "Could not find or load main class" error.
Class-Path: C:Program FilesMicrosoft JDBC Driver 4.0 for SQL Serversqljdbc_4.0enusqljdbc4.jar
Main-Class: com.ncntech.go
Is the syntax correct for specifying a directory path ?
When I assign a classpath-relative URL to an ImageView's 'Image' property, SceneBuilder is unable to display the Image in the Preview. It shows the text "Image not found" instead as a placeholder, which makes sense. What I'd like to do is add a classpath entry to SceneBuilder such that it is able to locate and display the Images. Any way to accomplish this (or similar)?
View Replies View RelatedI am looking for a way to compile Java Source-Files at runtime and save them all in an executable jar; almost like an IDE would do. I know that there is the javax.tools package which provides a JavaCompiler interface and you can use ToolProvider.getSystemJavaCompiler() to get an instance of a compiler. However, this method has one important problem: it only works on machines that have the JDK installed. Not when only the JRE is installed.
I guess at this point that I need some kind of third party library that offers an implementation of a JavaCompiler. Unfortunately, this is really complicated to search for on the internet since all top listings when searching "compile java at runtime jre" do not really provide a solution to the problem.
I am writing a (somewhat) complex simulation software right now which is supposed to be used by people who have absolutely no knowledge of programming. At the same time, this software should provide the user with a certain amount of flexibility and control over the flow of the simulation.
My previous take on this problem was to build a complex system to interprete user settings from a GUI. I would basically read the GUI input, output it to some kind of own scripting syntax which I just quickly made up and have that interpreted at runtime. Then I realized, that is a silly concept and I threw it out before I got far into the developement.
The much better solution I came up with is taking the input from the GUI, create java source code from it and compile it at run-time. Seems much cleaner and nicer to me; will also probably have a better performance, but thats not really an issue anyways.
The first 4 class below are the main classes while the last class is the testing class. I got it all to compile but for whatever reason there are several runtime errors. I have spent hours trying to figure out what they are, but I was only able to eliminate a few.
import java.util.*;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Set;
import java.lang.*;
public class PhoneNetwork {
[Code] .....
"Because X is a compile time constant, the compiler will Y"... But what exactly is a compile time constant? And how can we determine whether something is treated as such?Obviously, a compile time constant is a constant value that is known at compile time... ... Literals are, by definition, compile time constants -- as they are constants, known at compile time.
But the definition of a compile time constant is a bit more complex. To start, let's examine section 15.28 of the Java language specification.A compile-time constant expression is an expression denoting a value of primitive type or a String that is composed using only the following:
Literals of primitive type and literals of type String Casts to primitive types and casts to type StringThe unary operators +, -, ~, and ! (but not ++ or --)The multiplicative operators *, /, and %The additive operators + and - The shift operators <<, >>, and >>>The relational operators <, <=, >, and >= (but not instanceof)The equality operators == and !=The bitwise and logical operators &, ^, and |The conditional-and operator && and the conditional-or operator ||The ternary conditional operator ? : Simple names that refer to final variables whose initializers are constant expressions Qualified names of the form TypeName . Identifier that refer to final variables whose initializers are constant expressions
This is the full definition of a compile time constant. And as you can see, it contains more than just literals. In fact, literals are merely the first bullet point on the list. Also, note that a compile time constant can apply to any literal that is of primative or String type.The next few bullet points are the operations that can be applied to a constant at compile time. This list is actually pretty long, as it is possible to apply most of the operations at compile time. It may actually be easier to remember what can't be apply at compile time -- pre and post increment and decrement, instanceof operator, or any method calls, are not on the list.
The last few bullets are the most interesting. It is possible to use a variable in the expression -- provided that the variable is a compile time constant variable. So... what is a constant variable? Going back to the JLS (section 4.12.4 to be exact)..4.12.4 final Variables.A variable can be declared final. A final variable may only be assigned to once. It is a compile time error if a final variable is assigned to unless it is definitely unassigned (§16) immediately prior to the assignment.
We call a variable, of primitive type or type String, that is final and initialized with a compile-time constant expression (§15.28) a constant variable. Whether a variable is a constant variable or not may have implications with respect to class initialization (§12.4.1), binary compatibility (§13.1, §13.4.9) and definite assignment (§16).The last part of the definition is the relevant part (I still find it amazing that this is that well hidden in the specification). To be a variable that is a compile time constant, the variable needs to be...declared as finalhave a primative or String typeinitialized (on the same line as the declaration)assigned to a compile time constant expression.
I was wondering what happens to the API packages I've imported at compile time. Are they compiled to classes and placed In the same file as the class containing the Import command ?
The reason I'm asking Is because I've noticed the src.zip file Is not In the JRE and since the JRE Is all that's needed to run an app , I'd like to understand what the import command does.
I keep getting this error when compiling the code . I think its got to do with the Tomcat server not working well with the textpad app...I'm using windows 8.1(for the course I have to use Textpad 4.7.3 & Apache Tomcat 5.5.7 Server) :
C:UsersReignDownloadsIntec - Codecourse technology59850dChapter 12WorkWebStocks.java:20: package javax.servlet does not exist
import javax.servlet.*;
^
C:UsersReignDownloadsIntec - Codecourse technology59850dChapter 12WorkWebStocks.java:21: package javax.servlet.http does not exist
import javax.servlet.http.*;
[code]....
tom cat is running as a service it shows started in the tom cat app and as a running service in windows services !!!
I have a code in which I am reading input from System.in and Destination is some where else
Here is my code
File file=new File("D:/output.txt");
OutputStream os=new java.io.FileOutputStream(file);
Scanner scanner=new Scanner(System.in);
System.out.println("Enter Data to write on File");
String text=scanner.nextLine();
int c=Integer.parseInt(text);
int a;
while((a=c.read())!=-1)
os.write(a);
System.out.println("File Written is Successful");
In the line while((a=c.read())!=-1)
a compile time error is shown "cannot invoke read on primitive data type int"
Where I am going wrong?
I am working on an assignment that I can't seem to figure out the final part to. The program takes in course data such as the time the class starts and how long it lasts. The time is in military time (0000 - 2400)
I need the output time to be the time the class started, plus the length of the class, and displayed in military time.
for example,
Start Time = 0930
Length = 50 minutes
Endtime = 1020
I can't for the life of me figure out how to do this. I have gotten a program that works for this time and minutes, and displays the correct 1020. But when I change the information to say
Start time: 0700
Length = 90 minutes
I get:
Endtime = 90
90 is technically correct, the way the formula is setup, but I need it to display 0900 not 90.
Here is the code that I have. Be easy, I'm still learning, and this is just the file I created to get the formula to work. Also, the verbose in here is just for my own debugging to make sure values should be what I'm expecting them to be.
public class calc
{
public static void main(String[] args) {
double hours, minutes, length;
double temp;
int time = 2400;
hours = time / 100;
System.out.println("Hours are: " + hours);
[Code] ....
I have two classes. time_runner is used for testing my code.
This is what I'm using to test my code:
class time_runner
{
public static void main(String str[]) throws IOException {
Time time1 = new Time(14, 56);
System.out.println("time1: " + time1);
System.out.println("convert time1 to standard time: " + time1.convert());
System.out.println("time1: " + time1);
System.out.print("increment time1 five times: ");
time1.increment();
[code]....
The two constructors are "Time()", which is the default constructor that sets the time to 1200, and "Time(int h, int m)" Which says If h is between 1 and 23 inclusive, set the hour to h. Otherwise, set the hour to 0. If m is between 0 and 59 inclusive, set the minutes to m. Otherwise, set the minutes to 0. Those are my two constructors that I pretty much have down. The three methods however I'm having trouble with. The "String toString()" Returns the time as a String of length 4. The "String convert()" Returns the time as a String converted from military time to standard time. The "void increment()" Advances the time by one minute.
public class Time {
private int hour;
private int minute;
public Time(int h, int m) {
if(h > 1 && h < 23)
hour = h;
[code]....
i am getting runtime Exception Saying classCastException .here is my code where i am getting classcastException.
public class ModifyDetailsServlet extends HttpServlet {
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
[code]....
why get a runtime error when choosing option 2 after adding a contact?
Main:
package contactlist;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
[code]....
I have a question about updating a grid during runtime in GridWorld. I'm making a game called Flood-It (basically, you click on squares to change their color and attempt to get all of the squares the same color in the grid) and I'm having trouble with changing the grid size. I made my own world class, called CellWorld.
import info.gridworld.actor.*;
import java.util.ArrayList;
import info.gridworld.grid.Location;
import java.awt.Color;
import javax.swing.JOptionPane;
[code]...
Now, let me narrow down the issue. It is in the runner class:
world.setGrid(new BoundedGrid<Actor>(world.getLength(),world.getWidth()));
Whenever a user wants to change the grid size after playing the game, this is supposed to set the grid to the new updated size, but it never changes in the actual game, i.e. the user just won a 2x2 game, attempts to change the size to 10x10, but the grid stays 2x2. By debug testing, I can say for certain that everything else works, such as the maxStepCalc and loading the grid. The only issue is the new grid not showing up.
How can I add computed/derived column to an existing TableModel ?
I've 7 column in the existing TableModel. Now I've to add 8th column and it'll be based on Col2, Col3 & Col5.
Value of Col8 should be in following logic.
public TableModel GetDerivedTable(ResultSet rs){
TableModel model = GetTable(rs); // I've done this
//Now have to modify here
If(Col2==true && Col5==true)
Then{Col8 = 1}
[Code] ....
I am using Swing, I have a JPanel and in it there is a JTextArea and a JButton. I want the JTextArea to move when the button is clicked on. I'm Not really sure how to do the action listener for the button. at the moment the JTextArea only moves once when the button is clicked on, but i want it to move every time the button is clicked on.
This is what i have so far:
moveButton = new JButton("MOVE");
moveButton.setName("move");
moveButton.setBounds(20, 140, 70, 40);
text = new JTextArea("hello");
text.setEditable(false);
text.setBounds(x, 50, 40, 20);
panel.add(moveButton);
panel.add(text);
In the actionPerformed method this is what it does:
text.setBounds(x + 50, 50, 40, 20);
panel.add(text);
text.setVisible(true);
How can i take run time value for static final variable...my lecturer said first time assignment is possible for declared final variable but in my case it shows compile time error..I'm placing my program below with error message
class Sample
{
static final String cname;
void print() {
System.out.println(cname);
}
public static void main(String args[])
{
cname=args[0];
Sample s=new Sample();
s.print();
}
}
Sample.java:11: cannot assign a value to final variable cname.
cname=args[0];
I'm working in a project where a particular part has been assigned to me. I've a ResultSet of informations like below:
EmpId EmpFirstName EmpLastName EmpAge 1 ABC DEF 43 2 PQR XYZ 37
Now I've to send this ResultSet(to another function) with EmpFullName in following manner.
EmpId EmpFirstName EmpLastName EmpFullName EmpAge 1 ABC DEF DEF, ABC 43 2 PQR XYZ XYZ, PQR 37
There is no permission for me that I can change SQL query(or anything like this), and I've to return the modified ResultSet(not TableModel). I googled a lot to implement AbstractResultSet, but no luck for me. How can I achieve this ?