JNI动态注册 2

package com.biumall.dynamic.one;
public class Hello {
    // 1. load Hello.so
    static {
        System.loadLibrary("Hello");
    }
    // 2. define native sayHello()
    public static native void fromJavaHello(String message);
    public static native String fromJniHello();
}

public static native void fromJavaHello(java.lang.String);
    Signature: (Ljava/lang/String;)V
    
public static native java.lang.String fromJniHello();
    Signature: ()Ljava/lang/String;

灵活性高, 更改类名,包名或方法名时, 只需对更改模块进行少量修改, 效率高

//定义Hello.java类路径[包名+类名，只不过.换成了/]
//com.biumall.dynamic.one.Hello
#define DYNAMIC_CLASS "com/biumall/dynamic/one/Hello"

public static native void fromJavaHello(String message);
public static native String fromJniHello();

JNIEXPORT void JNICALL native_fromJavaHello(JNIEnv *env, jclass jc, jstring js){
    //Java String转char *str
    const char *str = (*env)->GetStringUTFChars(env, js, 0);
    LOGE("native_fromJavaHello : %s ", str);
    (*env)->ReleaseStringUTFChars(env, js, str);
}
​
JNIEXPORT jstring JNICALL native_fromJniHello(JNIEnv *env, jclass jc){
    return (*env)->NewStringUTF(env, "Hello from JNI!");
}

//定义Java和JNI函数的绑定表
// 方法数组，分别为：(方法名[java层定义的],方法签名,函数指针[c层对应替换的方法])
// 可以通过javac和javap 获取 方法签名
JNINativeMethod method_table[]= {
        {"fromJavaHello", "(Ljava/lang/String;)V", (void*) native_fromJavaHello},
        {"fromJniHello", "()Ljava/lang/String;", (void*) native_fromJniHello},
};