How to use classes from jar files

Question

I read the Java tutorials on Sun for JAR files  but I still can t find a solution for my problem  I need to use a class from a jar file called jtwitter jar  I downloaded the file  and tried executing it  I found out yesterday that  jar files can be executed by double clicking on them  and Vista gave me an error saying  Failed to load Main-Class Manifest attribute from  path  jtwitter jar    The guy who coded the  jar file wants me to import it  but where do I store the  jar file to import it in my code  I tried putting both the  jar file and my  java file in the same directory  didn t work   The file I m trying to work for is here  http   www winterwell com software jtwitter php  I m using JCreator LE

User · Answer

As workmad3 says  you need the jar file to be in your classpath  If you re compiling from the commandline  that will mean using the -classpath flag   Avoid the CLASSPATH environment variable  it s a pain in the neck IMO    If you re using an IDE  please let us know which one and we can help you with the steps specific to that IDE

User · Answer

You need to put the  jar file into your classpath when compiling running your code  Then you just use standard imports of the classes in the  jar

User · Answer

You need to put the  jar file into your classpath when compiling running your code  Then you just use standard imports of the classes in the  jar

User · Answer

You need to put the  jar file into your classpath when compiling running your code  Then you just use standard imports of the classes in the  jar

User · Answer

As workmad3 says  you need the jar file to be in your classpath  If you re compiling from the commandline  that will mean using the -classpath flag   Avoid the CLASSPATH environment variable  it s a pain in the neck IMO    If you re using an IDE  please let us know which one and we can help you with the steps specific to that IDE

User · Answer

You need to add the jar file in the classpath  To compile your java class   javac -cp   jwitter jar MyClass java   To run your code  provided that MyClass contains a main method    java -cp   jwitter jar MyClass   You can have the jar file anywhere  The above work if the jar file is in the same directory as your java file

User · Answer

Let s say we need to use the class Classname that is contained in the jar file org example jar  And your source is in the file mysource java Like this   import org example Classname   public class mysource       public static void main String   argv                        First  as you see  in your code you have to import the classes  To do that you need import org example Classname   Second  when you compile the source  you have to reference the jar file   Please note the difference in using   and   while compiling   If you are under a unix like operating system   javac -cp    org example jar  mysource java  If you are under windows   javac -cp   org example jar mysource java    After this  you obtain the bytecode file mysource class  Now you can run this     If you are under a unix like operating system   java -cp    org example jar  mysource  If you are under windows   java -cp   org example jar mysource

User · Answer

You need to put the  jar file into your classpath when compiling running your code  Then you just use standard imports of the classes in the  jar

User · Answer

You need to add the jar file in the classpath  To compile your java class   javac -cp   jwitter jar MyClass java   To run your code  provided that MyClass contains a main method    java -cp   jwitter jar MyClass   You can have the jar file anywhere  The above work if the jar file is in the same directory as your java file

User · Answer

Not every jar file is executable   Now  you need to import the classes  which are there under the jar  in your java file  For example   import org xml sax SAXException    If you are working on an IDE  then you should refer its documentation  Or at least specify which one you are using here in this thread  It would definitely enable us to help you further   And if you are not using any IDE  then please look at javac -cp option  However  it s much better idea to package your program in a jar file  and include all the required jars within that  Then  in order to execute your jar  like   java -jar my program jar   you should have a META-INF MANIFEST MF file in your jar  See here  for how-to

User · Answer

You need to add the jar file in the classpath  To compile your java class   javac -cp   jwitter jar MyClass java   To run your code  provided that MyClass contains a main method    java -cp   jwitter jar MyClass   You can have the jar file anywhere  The above work if the jar file is in the same directory as your java file

User · Answer

Let s say we need to use the class Classname that is contained in the jar file org example jar  And your source is in the file mysource java Like this   import org example Classname   public class mysource       public static void main String   argv                        First  as you see  in your code you have to import the classes  To do that you need import org example Classname   Second  when you compile the source  you have to reference the jar file   Please note the difference in using   and   while compiling   If you are under a unix like operating system   javac -cp    org example jar  mysource java  If you are under windows   javac -cp   org example jar mysource java    After this  you obtain the bytecode file mysource class  Now you can run this     If you are under a unix like operating system   java -cp    org example jar  mysource  If you are under windows   java -cp   org example jar mysource

User · Answer

Not every jar file is executable   Now  you need to import the classes  which are there under the jar  in your java file  For example   import org xml sax SAXException    If you are working on an IDE  then you should refer its documentation  Or at least specify which one you are using here in this thread  It would definitely enable us to help you further   And if you are not using any IDE  then please look at javac -cp option  However  it s much better idea to package your program in a jar file  and include all the required jars within that  Then  in order to execute your jar  like   java -jar my program jar   you should have a META-INF MANIFEST MF file in your jar  See here  for how-to

User · Answer

You need to add the jar file in the classpath  To compile your java class   javac -cp   jwitter jar MyClass java   To run your code  provided that MyClass contains a main method    java -cp   jwitter jar MyClass   You can have the jar file anywhere  The above work if the jar file is in the same directory as your java file

User · Answer

As workmad3 says  you need the jar file to be in your classpath  If you re compiling from the commandline  that will mean using the -classpath flag   Avoid the CLASSPATH environment variable  it s a pain in the neck IMO    If you re using an IDE  please let us know which one and we can help you with the steps specific to that IDE

User · Answer

Not every jar file is executable   Now  you need to import the classes  which are there under the jar  in your java file  For example   import org xml sax SAXException    If you are working on an IDE  then you should refer its documentation  Or at least specify which one you are using here in this thread  It would definitely enable us to help you further   And if you are not using any IDE  then please look at javac -cp option  However  it s much better idea to package your program in a jar file  and include all the required jars within that  Then  in order to execute your jar  like   java -jar my program jar   you should have a META-INF MANIFEST MF file in your jar  See here  for how-to

User · Answer

Not every jar file is executable   Now  you need to import the classes  which are there under the jar  in your java file  For example   import org xml sax SAXException    If you are working on an IDE  then you should refer its documentation  Or at least specify which one you are using here in this thread  It would definitely enable us to help you further   And if you are not using any IDE  then please look at javac -cp option  However  it s much better idea to package your program in a jar file  and include all the required jars within that  Then  in order to execute your jar  like   java -jar my program jar   you should have a META-INF MANIFEST MF file in your jar  See here  for how-to

User · Answer

As workmad3 says  you need the jar file to be in your classpath  If you re compiling from the commandline  that will mean using the -classpath flag   Avoid the CLASSPATH environment variable  it s a pain in the neck IMO    If you re using an IDE  please let us know which one and we can help you with the steps specific to that IDE

[java] How to use classes from .jar files?

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