Re: BufferedReader and BufferedWriter : non-static variable cannot be accessed from the static context
So...
Other people on this list have attempted to help prior to this reply. They are
much nicer than
I.
1. You *never* asked a question. You posted a bit of code and indicated
there was an
error. You didn't indicate that you tried to figure out the error or anything
else. The people
who subscribe to this list aren't your parents and are under no obligation to
try to read your
mind (assuming your parents have that obligation) to solve your _unstated_
problems.
2. This mailing list is to discuss Netbeans issues. Basic java problems
really shouldn't be
addressed here, although I might be in the minority in this mailing list with
that opinion.
There are ample places other than this list to find an answer to your implied
problem.
--
Mark A. Flacy
mfl...@verizon.net
On 2022 M05 22, Sun 17:52:55 CDT Zulfi Khan wrote:
> Hi,
> I have written the following code:
> /*
> * Click
> nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to
> change this license * Click
> nbfs://nbhost/SystemFileSystem/Templates/Project/Maven2/JavaApp/src/main/ja
> va/${packagePath}/${mainClassName}.java to edit this template */
>
> package com.mycompany.add2strjop;
> import javax.swing.*;
> import java.lang.NumberFormatException;
> import java.io.FileWriter;
> import java.io.FileReader;
> import java.io.BufferedWriter;
> import java.io.BufferedReader;
> import java.io.IOException;
> public class Add2StrJOp {
> BufferedReader BF= null;
> BufferedReader BW= null;
> String str = "test";
>
>public static void main(String args[]){
> try{
> FileReader file = new FileReader("abc.txt");
> BF = new BufferedReader(file);//E
> //BF= new BufferedReader(new FileReader("abc.txt"));
> while ((str = BF.readLine())!=null){//E
> JOptionPane.showMessageDialog(null, str);//E
> //JOptionPane.showMessageDialog(null, "hello World");
> //BF.clos()
> }
> }catch(IOException e){
> e.printStackTrace();
> }
> finally{
> try{
> if( BF!=null){//E
>BF.close();//E
> }
> }catch(IOException e) {
> e.printStackTrace();
> }
> }//finally
> try{
> BW = new BufferedWriter(new FileWriter("abc.txt"));//E
> String str= "This is a test";
> BW.write(str);//E
> BW.close();//E
> }catch(IOException e) {
> e.printStackTrace();
> }
> }
> }
>
>
> I have commented the lines as //E where I am getting the error "Non-static
> variable cannot be referenced from static context. Zulfi.
Netbeans with Snap packaged OpenJDK
I just installed Netbeans and OpenJDK onto by Kubuntu 22.04 LTS. For some reason the required aliases to map openjdk.java to java, etc. were not created when OpenJDK was installed. I created the aliases found in the file /var/snap/openjdk/common/openjdk.env. Typing "java", "javac", "jar" into a command line now produces the expected results. However when in attempt to invoke Netbeans, it complains that it can't find java and that the --jdk-home option should be used. I've tried several variations of this /snap/bin, etc. but I still get the "can't find java" message. Has anybody else encountered this problem, or know of any easy installation that will get me jdk that netbeans recognizes?
Re: NB 13 - Markdown files
Hi Neil. That was it, thanks. Brad. On 23/4/22 15:53, Neil C Smith wrote: On Sat, 23 Apr 2022 at 08:25, Bradley Willcott wrote: I am trying to edit some markdown files in NB 13. However, when I right-click on the file in the Projects Explorer, all I get is "Open as Binary". Hit the "Way-Back Machine", and using NB 12.6, doing the same thing I get "Open" plus a number of other options to choose from, including the "Open as Binary" option. Is it just my installation, or has something broken in the Markdown extension, or NB 13? It's a bug in the BinEd plugin that you must have installed. See this https://github.com/apache/netbeans/issues/3797 Best wishes, Neil - To unsubscribe, e-mail: users-unsubscr...@netbeans.apache.org For additional commands, e-mail: users-h...@netbeans.apache.org For further information about the NetBeans mailing lists, visit: https://cwiki.apache.org/confluence/display/NETBEANS/Mailing+lists
create serialVersionUID
Hello, In Netbeans, how can i create the serialVersionUID number of a class? thanks! Roberto. - To unsubscribe, e-mail: users-unsubscr...@netbeans.apache.org For additional commands, e-mail: users-h...@netbeans.apache.org For further information about the NetBeans mailing lists, visit: https://cwiki.apache.org/confluence/display/NETBEANS/Mailing+lists
Re: BufferedReader and BufferedWriter : non-static variable cannot be accessed from the static context
Try declaring BF, BW and test inside the main method or declare them as
public static.
On 5/23/22 01:46, John Barrow wrote:
I am relatively new to Java, and get this occasionally myself due to
the "static main" method being typed within the class.
The issue is that you are trying to access "BF" and "str" that exist
inside a class, from a static environment (main). I think it would
have helped if the exception had been a little more explicit,
mentioning the fields that were at fault.
If you were accessing the class from another source file (class) you
would first have to create an instance, i.e.
Add2StrJOp myAdd2StrJOp = new Add2StrJOp();
Then you could access "BF" and "str" as
myAdd2StrJOp.BF and myAdd2StrJOp.str.
As the main method is a static method, it also needs to create an
instance of Add2StrJOp using "new" before you can access the fields
within the class, just as if using your class from an external source
file.
So add the line above at the top of your main method, just after the
"try {" line and then prefix the class fields with your newly created
instance variable to reference them.
Hope that helps.
John
On Sun, 22 May 2022, 23:53 Zulfi Khan,
wrote:
Hi,
I have written the following code:
/*
* Click
nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt
to change this license
* Click
nbfs://nbhost/SystemFileSystem/Templates/Project/Maven2/JavaApp/src/main/java/${packagePath}/${mainClassName}.java
to edit this template
*/
package com.mycompany.add2strjop;
import javax.swing.*;
import java.lang.NumberFormatException;
import java.io.FileWriter;
import java.io.FileReader;
import java.io.BufferedWriter;
import java.io.BufferedReader;
import java.io.IOException;
public class Add2StrJOp {
BufferedReader BF= null;
BufferedReader BW= null;
String str = "test";
public static void main(String args[]){
try{
FileReader file = new FileReader("abc.txt");
BF = new BufferedReader(file);//E
//BF= new BufferedReader(new FileReader("abc.txt"));
while ((str = BF.readLine())!=null){//E
JOptionPane.showMessageDialog(null, str);//E
//JOptionPane.showMessageDialog(null, "hello World");
//BF.clos()
}
}catch(IOException e){
e.printStackTrace();
}
finally{
try{
if( BF!=null){//E
BF.close();//E
}
}catch(IOException e) {
e.printStackTrace();
}
}//finally
try{
BW = new BufferedWriter(new FileWriter("abc.txt"));//E
String str= "This is a test";
BW.write(str);//E
BW.close();//E
}catch(IOException e) {
e.printStackTrace();
}
}
}
I have commented the lines as //E where I am getting the error
"Non-static variable cannot be referenced from static context.
Zulfi.
Re: BufferedReader and BufferedWriter : non-static variable cannot be accessed from the static context
I am relatively new to Java, and get this occasionally myself due to the
"static main" method being typed within the class.
The issue is that you are trying to access "BF" and "str" that exist inside
a class, from a static environment (main). I think it would have helped if
the exception had been a little more explicit, mentioning the fields that
were at fault.
If you were accessing the class from another source file (class) you would
first have to create an instance, i.e.
Add2StrJOp myAdd2StrJOp = new Add2StrJOp();
Then you could access "BF" and "str" as
myAdd2StrJOp.BF and myAdd2StrJOp.str.
As the main method is a static method, it also needs to create an instance
of Add2StrJOp using "new" before you can access the fields within the
class, just as if using your class from an external source file.
So add the line above at the top of your main method, just after the "try
{" line and then prefix the class fields with your newly created instance
variable to reference them.
Hope that helps.
John
On Sun, 22 May 2022, 23:53 Zulfi Khan, wrote:
> Hi,
>
> I have written the following code:
>
> /*
> * Click
> nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to
> change this license
> * Click
> nbfs://nbhost/SystemFileSystem/Templates/Project/Maven2/JavaApp/src/main/java/${packagePath}/${mainClassName}.java
> to edit this template
> */
>
> package com.mycompany.add2strjop;
> import javax.swing.*;
> import java.lang.NumberFormatException;
> import java.io.FileWriter;
> import java.io.FileReader;
> import java.io.BufferedWriter;
> import java.io.BufferedReader;
> import java.io.IOException;
> public class Add2StrJOp {
> BufferedReader BF= null;
> BufferedReader BW= null;
> String str = "test";
>
>public static void main(String args[]){
> try{
> FileReader file = new FileReader("abc.txt");
> BF = new BufferedReader(file);//E
> //BF= new BufferedReader(new FileReader("abc.txt"));
> while ((str = BF.readLine())!=null){//E
> JOptionPane.showMessageDialog(null, str);//E
> //JOptionPane.showMessageDialog(null, "hello World");
> //BF.clos()
> }
> }catch(IOException e){
> e.printStackTrace();
> }
> finally{
> try{
> if( BF!=null){//E
>BF.close();//E
> }
> }catch(IOException e) {
> e.printStackTrace();
> }
> }//finally
> try{
> BW = new BufferedWriter(new FileWriter("abc.txt"));//E
> String str= "This is a test";
> BW.write(str);//E
> BW.close();//E
> }catch(IOException e) {
> e.printStackTrace();
> }
> }
> }
>
>
>
> I have commented the lines as //E where I am getting the error "Non-static
> variable cannot be referenced from static context.
>
> Zulfi.
>
>
>
