问题
I am new to eclipse and I have a general question about referencing external Jar files.
I went to the buildpath -> configure build path and added my two jar files that I wanted to reference as parts of an external library but I can seem to make an instance object of the classes in that jar.
And also I tried just copy and pasting the jar files to the extension folder of the standard library too but this also doesn't work.
How can I use the instance objects of the classes included in these jar files?
回答1:
Even if you build path to external JARs you have to import the required classes because they do not actually exist inside the same package you are working at.
回答2:
if u want to add external jars into eclipse follow these steps
Rightclick on project - Select Configure Build Path... and the project properties window will appear showing your build path configurations.
Click Add Variable --Click Configure Variables Click New -Type a name for the new variable.--Browse to the directory that contains the JAR for the path. Click Ok to define the variable.--Click Ok to close the preferences dialog. Select the variable from the list.--Click Extend.. Select the JAR(s) that you want to add to the classpath.--Select the JAR(s) that you want to add to the classpath.-Click Ok to close the new classpath variable dialog.
回答3:
If you already added jar file into classpath and if it doesn't work I would try below on command prompt
java -classpath example.jar;
来源：https://stackoverflow.com/questions/26104786/classpath-jar-files-in-eclipse