Question: What would be the easiest way to view classes, methods, properties, etc. inside a jar file?
I'm looking for something equivalent to the very useful  *Lutz Roeder .NET Reflector*  - for Java

Answer: 
> 
> In case someone don't know this already, a JAR file is just a ZIP file
>  that contains the program's classes, resources, etc., and some
>  metadata. You can extract one to see how it's put together.
> 
> 
> 

Hence I am using `unzip` command which is easy to remember and use.

`unzip -l <jar-file-name>.jar` 

For example, if you have a jar file with name `test.jar` then `unzip -l test.jar` will list all the content of jar file.

**While all other answers are great, but in most of them, you would have to use some software like `7 zip` or `JDK` or some other eclipse tool while this doesn't require you to have any of these big s/w and it comes by default in linux and mac so its very lightweight and handy to use**. 

You can also use `zipinfo <your jar file>`. if your OS supports this.
If you are in windows and using powershell and you are looking for a file in a jar you can do:

```
jar -tf .\[JAR_NAME] | where {$_ -match "[FILENAME]"}

```