javap 可以打印出用于jni调用的java函数的签名信息

javap可以打印出java的字节码：

-c     Prints out disassembled code, i.e., the instructions that comprise the Java bytecodes, for each of the methods in the class. These are documented in the Java
             Virtual Machine Specification @
             http://docs.oracle.com/javase/specs/.

 

javap还可以打印出用户jni本地native调用的函数签名信息，不过只打印.class文件，不能打印.java文件，必须将.java文件编译为.class文件：

javap -classpath .  ??.class

javap -classpath . -s -p  ??.class