Import a class directly in classpath,without package.

In jdk1.3, I can
--------------------------- import MyClass;
MyClass is in my classpath.
But in jdk1.4,
--------------------------- import MyClass;
cannot been compiled success.
exception: "." expected.
Why?

That's right. Importing a class that wasn't in a
package was always pointless, and in 1.4 it's actually
illegal.I am not as certain that I believe in the 'pointless' part.
As it stands now, a class that does not have a package can not be used in a class that has a package. Not that that is a great loss, but the result certainly surprised me.

Similar Messages

Possible to access classes in other folders without the use of packages?

Hi,
I'm trying to write a kind of connector application, and I have come across this stumbling block.
I have a folder for my main program classes, which will not change. External to that folder( either in a subdirectory or another directory on the same level) I want to have my classes to "connect". The connected classes will be compiled dynamically, as they depend on something in the main classes folder for complilation... I trust I can satisfy that using javac -classpath...
The problem is that I would like one of the main classes to be able to access the connected classes at runtime, from the other folder. The collection of connected classes will be changing, so that, coupled with the fact that one of the main classes will be required to compile each connected class seems to rule out the use of packages for the connected classes.
Is there a way to get around this?
Thank you,
Jesse

Are you trying to dynamically compile Java classes (in external folders
without packages) via Java? Yes, I will be (hopefully) using com.sun.tools.javac. I haven't done that part yet, as I don't want to waste my time on a design that is fundamentally flawed :)
Does each new 'application' get placed into its ownfolder? No. I will be building a collection of new apps that will all be contained in one folder.
Once an application is compiled, must it beimmediately available to the process that compiled
it? Yes. Once an application is compiled I need it to be accessable from that point on.
Thanks,
Jesse

Import class without package

hellow, i have a web aplication named test , and i have a class named conexion
when i import a package "pack" with the class conexion, not problem (test/WEB-INF/classes/pack/conexion.class) <% import="pack.* " %> but when i have only the class conexion WITHOUT package (test/WEB-INF/classes/conexion.class) and i import <%import ="conexion" %> i have problem ("The import conexion cannot be resolved") and when i not import the class i have problem (conexion cannot be resolved to a type) , my question is:
how to i import a class without package in JSP , and if the test/WEB-INF/classes is in the classpath when compile the servlet , why the tomcat not found the class conexion?
(tomcat 5.5.20 , jdk 1.5.09 , vim)
thank
(Sorry my english , i'm from Chile)

Hi I am hosting my JSP application with Resin 2.17 which uses classes directly in JSP code (not packages). To make this work I had to specify the classpath in Resin.conf and it worked.
My problem is getting this to work with TomCat or any other application server that will allow me to debug my project in Eclipse or NetBeans IDE. (I have yet to find an IDE that Supports debugging JSP/Java code running on Resin - so I want to switch my application server but I am not sure how to configure my classpath for the application servers to look for java classes in the specified directory just like I did with Resin.

Not allowed to import classes without package names?

Hi,
I have a few questions on Packages and importing?
1. Is the following true that it is illegal to import classes in the same package as the current class, will this cause a comilation error? If this is the case where in the Java Language specification is this actually written as I could not find it?
2. This has probably been answered by question 1 but if I have 2 classes in the same package and if I import 1 of the classes into the other class, is it illegal to import it by just using the class name and not the package name as well, ie
if the package name is ie.tcd
and the 2 class names are exp1.class and exp2.class, can I do this in class 2
package ie.tcd;
import exp1;
public class exp2 {
3. Is it illegal to import classes that are not explicitly part of any package or must a class be part of a package to be imported. I read somewhere that while this was always illegal it is only after jdk 1.4.2 that this is being enforced? If this is the case where in the Java Language specification is this actually written as I could not find it either?
Thanks very much for any help,
John

Was just also wondering, 1 other thing, I am looking
at someone elses code they have 2 classes (Class A
and Class B) in the same package (pkg). The person
imports class A into B:
package pkg;
import A;
public class B {
Is this legal code (or was it ever)?Not if A is really in pkg.A. If there is an A in the unnamed package it was legal, or at least it was understood by the compiler, and now it isn't (to both).
Can you import or is there a point in importing a class in the same
package?Only by naming the package in the import statement. If the current and the import statement are in the same package the import is redundant.
If there is a point would you import just be
using the class name (this would be illegal after jdk
1.4) or should you use the whole package name even
though it is in the package anyways?As I understand it you must always use the whole package name in imports.

A classpath error while importing a class with @page import property

Hi ,
I am using Tomcat contaniner for jsp applications. I have developed a page that i have import a class. when i use
<%@ page import="myclass" &>
i got an error that myclass not found. I have placed into tomcat\webapps\myproject\web-inf\classes directory. So How will I set the classpath for myclass to work?
thanks.

I was able to simulate your problem when I created a mismatch in the case of the name of the class.
for example if my program is called MyClass.java
and in the import I do <@page import="myclass" %>
Are you sure about the case of class name that you are using? Please check that the file is called myclass.java the class defined inside it is called myclass and the class file that is copied into the WEB-INF/classes directory is also myclass.class. There should be no difference in the case of the names. like MyClass.java or MyclaSS.class
Other things to check are
1. If myclass is defined in a package then you have to import with the package.
2. Make sure that your jsp is located in the myprojects directory and the class file is copied under myprojects/WEB-INF/classes.
Let me know if things still don't work
regards,
Abhishek.

How to import a class from a package at the same level

Hello friends,
i have a class as Plaf.java
as
package org.vaibhav.swing.plaf;
import java.awt.*;
import javax.swing.*;
public class Plaf {
other code
}as you see, this is in org.vaibhav.swing.plaf package.
I have one more class as
package org.vaibhav.swing.frames;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class StartFrame extends JFrame implements ActionListener {
other code
}and this class is in package org.vaibhav.swing.frames
Please hlp me how to use the class Plaf in StartFrame.java. Rather what import statement should i use in StartFrame.java.
please help.
thank you
Message was edited by:
vaibhavpingle

but it then gives me this error
StartFrame.java:11: package org.vaibhav.swing.plaf
does not exist
import org.vaibhav.swing.plaf.*;
Have you first compiled Plaf.java and saved it in this directory strucuture
/org/vaibhav/swing/plaf/
And also have you set your classpath to the parent directory of org folder.
Message was edited by:
qUesT_foR_knOwLeDge

How to import a class, which is not in a package?

Hi all,
I have the following problem:
A class A is not in a package. In another class B, which is in a package (let's say package X) I want to use the class A. Without importing the class A, I get the error "Cannot resolve symbol".
Using the import statement import A; gives the error ". expected".
How can I import that class?
Best wishes to all ...
Heiko

> I have the following problem:
A class A is not in a package. In another class B,
which is in a package (let's say package X) I want to
use the class A. Without importing the class A, I get
the error "Cannot resolve symbol".
I think not putting a class in a package is a bad practice. Avoid that.

Import the classes in the package java.util

I haven't taken a class in two years so I have ideas but am unsure of myself, and I most likely am way off base, but is this how you import the classes in the package java.util
import java.util.*;
I would appreciate anyone's help. I have a lot of questions.
Thanks,
rp

My assignment is below so that you will know exactly what I am asking. I am being asked to create an instance of LinkedList. I know that this is a part of the java.util. So when you create an instance of LinkedList would that be similar to instance variables? or am I misunderstanding something. I have several ideas, so I will start with the first one.
LinkList();
I really appreciate your taking the time to answer my questions to help me to rebuild my confidence in doing this.
Thanks,
// 2. import the classes in the package java.util
public class MyProgram
     public static void main(String [] args)
          // 3. Create an instance of LinkedList
          // 4. add 5 entries to the list so that it contains
          //     Ann, Bart, Carl, Dirk, Zak
          // 5. display the list on one line using a loop and ADT list methods
          System.out.println("\n\n3. ");
          // 6. display the list using one println
          System.out.println("\n\n4. ");
          // 7. create a ListIterator object for the list
          // 8. display the list on one line using the iterator
          System.out.println("\n\n6. ");
          // 9. restore the iterator to the first item in the list
          // 10. retrieve and display the first item in the iteration,
          //      then advance the iterator to the next item
          System.out.println("\n\n8. ");
          // 11. advance the iterator to the end of the list without displaying anything;
          //      do not use the length of the list
          // 12. display the last item in the list
          System.out.println("\n\n10. ");
          // 13. move back to the beginning of the list without displaying anything;
          //      do not use the length of the list
          // 14. display the first item in the list
          System.out.println("\n\n12. ");
          // 15. advance the iterator to the end of the list without displaying anything;
          // 16. advance the iterator - what happens?
          System.out.println("\n\n14. ");
          // 17. advance the iterator within a try block; catch the exception, display a message,,
          //      and set the iterator back to the beginning of the list.
          System.out.println("\n\n15. ");
          // 18. what does nextIndex and previousIndex return?
          System.out.println("\n\n16. ");
          // 19. move the iterator to the third item in the list; if you were to
          //      execute next(), the third item would be returned and the iterator
          //      would advance to the 4th item.
          System.out.println("\n\n17. ");
          // 20. add the string "New" to the list; where is it inserted relative to
          //      the current item in the iteration?
          System.out.println("\n\n18. ");
          // 21. remove the current item; what happens?
          System.out.println("\n\n19. ");
          // 22. display the current item in the list without advancing the iteration
          //      in 2 ways, as follows:
          // 22A - using only iterator methods
          System.out.println("\n\n20A. ");
          // 22B using an iterator method and list methods
          System.out.println("\n\n20B. ");
          // 23. advance the iterator and remove the current item; which one is removed?
          System.out.println("\n\n21. ");
          // 24. move the iterator back and remove the current item; which one is removed?
          System.out.println("\n\n22. ");
          // 25. move the iterator to the first item in the list and change it to "First"
          System.out.println("\n\n23. ");
     } // end main
} // end MyProgram

Classpath problems when importing my classes

I'm using a tutorial with sample programs dealing with bank accounts.
I get this error:
InterestBearingAccount.java [9:1] '.' expected
import Account;
^
1 error
Errors compiling InterestBearingAccount.
The Account class already exists in the current directory. I've tried everything as far as setting the classpath variable (nothing, just a period, period & slash, the actual complete path for the current directory, nothing works!!!!!). I also tried using -classpath (.) and the end of my javac command and that seemed to not work at all.
The Java Coffee Break tutorial have some already compiled (*.class) files and they run fine. My *.java files are identical. In fact, I cut and pasted them so I know it's not a typo.
My path is set to include the jdk1.4.0\bin directory and I've only begun to have problems now that I need to import existing classes into the programs.
I should mention that I get the same error using Forte environment or doing it at the command prompt window. Please help.

Thanks ATMGUY. I commented out the import statements in both InterestBearingAccount and AccountDemo and it worked fine. I guess the author of that tutorial was obviously not working with jdk 1.4.
As far as using packages, com.kusek.bank would make a good package name then??
The statement:
package com.kusek.bank; OR a shorter version package kusek.bank;
should be added to all three classes and no import statements would then be necessary, right??
I just remember reading that it should be something unique as a good habit to get into.
I'm trying to learn enough to make a useful GUI program for a special project so I probably should be using packages anyway when I get to that point.
My programming backround is limited to procredural languages Basic, QBasic, Pascal, and Fortran and I find myself still wanting to think in those terms. I have read several web sites and worked through some basic examples but I still have much to learn. I once I can grasp how to write OOP style it would be nice to look at code for a somewhat detailed application (like a store checkout app) and have every line explained as to why it's there. I can see where it makes sense to have your GUI classes predefined (Swing), File I/O, serial port communications, and even things like this InterestBearingAccount example that extends from the Account class utilizing its basic attributes but overriding the constructors for the additional parameters (interest calculation) that are passed. How to take a common problem and go about creating a solution is what I need to see being done to help me.
My telemetry project uses VHF radios with packet radio modems to monitor two diesel engines and turn one off if the other turns off. The modems have built in A/D data gathering and can also output control signals, they just need to be told what to do. I can manually use a Windows Hyperterminal session and type in "connect Engine1" and use commands to determine the A/D inputs "analog". The modems have built in end-to-end acknowledgement so the only think I need is an application than can be setup to run in the Startup folder to handle this. It would use a timer class to "poll" engine1 every 5-10 minutes and if it has stopped (based on the response of the "analog" command) I would "disconnect" from engine1 and "connect" to engine2 and send a "ctrl B off" or something similar. The standard responses from the modem should allow me just to send and recieve STRING data to and from the serial port and parse them as needed. I need at least this much but it shouldn't be too much harder to develop a way to reset the system(reverse of this) when that is required. I could also read a water pressure value at one of the locations and display that on the screen along with the current status of the engines (using values obtained from the "analog" command on the modems).
The hardest part of OOP programming seems to be knowing what classes are already out there and knowing how to find them or apply them. I hope Swing has classes that provide for displaying values on the Windows taskbar (my motherboard monitor freeware displays temperature readings down on the taskbar). I appreciate all the help given here. It's almost like having a private tutor.
randy

How to import a class that have no package

I have .class archive that i need to use in a web aplication on Tomcat. I put the class in the directory: <webapp>/WEB-INF/classes/.
The class doesn�t have a package, so when i tried to import (..page Import=".....") it, tomcat gave me an error because is looking for a package instead of the class.
then i try to use it without the import and tomcat gave another error because it can�t find the class.
Any ideas??
by the way.. I don�t have the source code, I just have the .class archive..
thank you....

Also, I already found that the class had no package. Then you are out of luck.
As of java 1.4 you can no longer import classes that are not in a package. [url http://bugs.sun.com/bugdatabase/view_bug.do;jsessionid=c85f07c1ce8f344d787b7a5146d68:WuuT?bug_id=4361575 ] Full details here
The only solutions I can think of
1 - get the people who originally gave you the class to package it properly.
2 - Decompile it to java code, Change the java code to put it in a package and recompile it. Depending on the complexity of the class this may or may not be a trivial operation.
Good luck,
evnafets

Classes without packages not accepted by ejbc compilation ?

Hey guys ...
I noticed something which I found unusual...I mite be missing something out here
When ejbc generates the Bean IMPL class , it does not put any import statements
in the generated java file but references all the classes in the Bean with their
absolute path ...
Now ..I have a 3rd-party jar which does not have certain classes in packages...and
I reference these classes within my Session Bean...the session bean compiles properly
..but when ejbc happens and the Impl class gets generated with the absolute path
and no imports...the compiler expects to find all these 3rd-party classes without
packages within the current session bean package itself which it will not..and
hence throws all sorts of "cannot resolve symbol" errors...
Does this mean that within my EJB beans I can never reference classes without
packages or is there something I am missing..?
Thanx,
Krish

Rob ,
I agree with u that giving classes without package is not a good practise..but
Itz got a history which believe it or not stems from another weblogic problem(related
to webservices..)
anywayz..that is another issue alltogether...
I don't think this bug is fixed...coz I checked a WLS70 Impl and it is still generating
the IMPL without the imports...
But can u clarify..what u wud mean by "fixing the bug" ..does it mean that the
Impl would start putting the imports..?
Thanx,
Krish
Rob Woollen <[email protected]> wrote:
I recall this bug being reported before. You might try the latest
service pack and see if it's been fixed already. Otherwise, you'll have
to contact [email protected]
FWIW, it's quite disturbing that a 3rd party would give you a jar
without a package.
-- Rob
Krishnan Venkataraman wrote:
Hey guys ...
I noticed something which I found unusual...I mite be missing
something out here
When ejbc generates the Bean IMPL class , it does not put any import
statements
in the generated java file but references all the classes in the Bean
with their
absolute path ...
Now ..I have a 3rd-party jar which does not have certain classes in
packages...and
I reference these classes within my Session Bean...the session bean
compiles properly
..but when ejbc happens and the Impl class gets generated with the
absolute path
and no imports...the compiler expects to find all these 3rd-party
classes without
packages within the current session bean package itself which it will
not..and
hence throws all sorts of "cannot resolve symbol" errors...
Does this mean that within my EJB beans I can never reference classes
without
packages or is there something I am missing..?
Thanx,
Krish

Import individual classes or entire package?

Hi All,
This is just a general curiosity question but I was wondering what the best way is to import mulitple classes from the same package. i.e. is it better to do something like this:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;or this:
import java.awt.*;Is the compiler smart enough to only import the needed classes as would be the case in 'import java.awt.*;'?

This document had some pretty good reason not to use the .* import:
http://wwws.sun.com/software/sundev/whitepapers/java-style.pdf
- The most important reason is that someone can later add a new unexpected class file to the same package
that you are importing. This new class can conflict with a type you are using from another package,
thereby turning a previously correct program into an incorrect one without touching the program
itself.
- Explicit class imports clearly convey to a reader the exact classes that are being used (and which classes
are not being used).
- Explicit class imports provide better compile performance. While type-import-on-demand declarations
are convenient for the programmer and save a little bit of time initially, this time is paid for in
increased compile time every time the file is compiled.

How to import a class not in the package from a package

how to import a class not in the package from a package?

http://java.sun.com/docs/books/tutorial/java/interpack/usepkgs.html

How do I import an image directly from the internet without printing and scanning it in first?

How do I import an image directly from the internet without printing and scanning it in first?

You can also Ctrl click on the image, save the image to your desktop and open it in Photoshop.
1.
2.
3. Open in Photoshop by double-clicking on the saved image on your Desktop or Cmd o in Photoshop.
I don't see any point to copying and pasting from a browser into a new file in Photoshop.
If you want to put an image onto an already open image in Photoshop, use the File > Place... command and select your saved image.
Gene

Importing a .class file into my package?

Hi. I'm making a java program but I need to use an external .class file to get variables and use methods from. Is it possible to "import" a class file into my package to be able to do so?
Thanks

Basically, for our last project we created a class
that held the information about a year: how many days
were in a month, how many months were in a year, etc.
etc. For this project, we'll be having to use that
same class to make a GUI calendar. Our teacher
provided a class which he compiled for us to use in
our projects incase our previous class had some flaws
in it, which mine did. Unfortunately, it's in .class
format and I don't know how to use it in my package!That's going to be a problem then. I would assume that it is going to have an API like your old one did. Same name and same methods etc. So do you know what the name and method signatures of your class were supposed to be?

Import a class directly in classpath,without package.

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