Android jni Development notes

I used to have a casual experience with JNI on android. So I subconsciously think this is nothing.

But this is actually not the case. The following are some of the issues that have plagued me during JNI development:

JNI development steps:

Step 1 declare the function definition in the java File

Step 2: Use the javah tool to compile the class file compiled by the java file into the. h header file.

Step 3 compile a specific function implementation in C Based on the H file.

Step 4: Compile the. c file as the so Library (ndk needs to be used here) and then call it in java.

Path of the header file:

1. Adjust the current path to the path before com, that is, the path of the normal java command,

2. The command for generating the header file is javah-classpath.-jni package name + class name.

Question about generating the so file:

1. to generate the so file, you must create a new jni directory in the android Application project, and then perform operations in the jni directory.

2. Enter the jni directory in the cygwin environment and enter $ NDK/ndk-build for automatic compilation.

JNI Syntax:

This is a complicated part in jni development.