问题描述

目标:将Java链接到Swift

问题:我得到 UnsatisfiedLinkError 尝试加载jni .dylib文件时，该文件与swift .dylib链接时，当调用 System#loadLibrary(String) ..

预期行为:将自动加载Java .dylib的依赖性，或者对System.loadLibrary(“SwiftCode”)的调用将加载依赖项(我可以提出的唯一解决方案).

注意:我正在结合 a href =” https://medium.com/@bschlining/a-simple-java-native-interface-interface–jni-example-in-java-in-java-in-scala-68fdafe76f5f” rel =” nofollow noreferrer”>/a>创建我的jni .dylib文件和 >文件.

完整的堆栈:

Exception in thread "main" java.lang.UnsatisfiedLinkError: /Users/hillmacbookpro/IdeaProjects/JavaToSwift/src/native/libSwiftHelloWorld.dylib: dlopen(/Users/hillmacbookpro/IdeaProjects/JavaToSwift/src/native/libSwiftHelloWorld.dylib, 1): Library not loaded: libSwiftCode.dylib
  Referenced from: /Users/hillmacbookpro/IdeaProjects/JavaToSwift/src/native/libSwiftHelloWorld.dylib
  Reason: image not found
    at java.base/java.lang.ClassLoader$NativeLibrary.load0(Native Method)
    at java.base/java.lang.ClassLoader$NativeLibrary.load(ClassLoader.java:2408)
    at java.base/java.lang.ClassLoader$NativeLibrary.loadLibrary(ClassLoader.java:2465)
    at java.base/java.lang.ClassLoader.loadLibrary0(ClassLoader.java:2662)
    at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2627)
    at java.base/java.lang.Runtime.loadLibrary0(Runtime.java:829)
    at java.base/java.lang.System.loadLibrary(System.java:1833)
    at helloworld.SwiftHelloWorld.<clinit>(SwiftHelloWorld.java:7)

文件结构:

src
  - helloworld
      - SwiftHelloWorld.java
  - native
      - libSwiftHelloWorld.dylib
      - libSwiftCode.dylib

mcve:

SwiftHelloWorld.java:

package helloworld;

public class SwiftHelloWorld {

    static {
        System.loadLibrary("SwiftCode"); // loading SwiftHelloWorld's dependency first
        System.loadLibrary("SwiftHelloWorld"); // exception thrown here, can't find dependency?
    }

    public static native void printHelloWorldImpl();

    public static void main(final String[] args) {
        printHelloWorldImpl();
    }

}

libSwiftHelloWorld.dylib:使用这两个终端命令创建:

export JAVA_HOME="$(/usr/libexec/java_home -v 11)"; gcc -I"$JAVA_HOME/include" -I"$JAVA_HOME/include/darwin/" -o libSwiftHelloWorld.dylib -dynamiclib helloworld_SwiftHelloWorld.c libSwiftCode.dylib

和这些文件:

• helloworld_SwiftHelloWorld.c:

  #include <jni.h>
  #include <stdio.h>
  #include "helloworld_SwiftHelloWorld.h"
  #include "helloworld_SwiftHelloWorld_swift.h"
  
  JNIEXPORT void JNICALL Java_helloworld_SwiftHelloWorld_printHelloWorldImpl
    (JNIEnv *env, jclass clazz) {
  
      int result = swiftHelloWorld(42);
      printf("%s%i%s", "Hello World from JNI! ", result, "\n");
  
  }

• helloworld_SwiftHelloWorld.h:自动生成的JNI标头
  javac -h native/ helloworld/SwiftHelloWorld.java

• helloworld_SwiftHelloWorld_swift.h:

  int swiftHelloWorld(int);

libSwiftCode.dylib:使用swiftc SwiftCode.swift -emit-library -o libSwiftCode.dylib和SwiftCode.swift文件创建:

import Foundation

// force the function to have a name callable by the c code
@_silgen_name("swiftHelloWorld")
public func swiftHelloWorld(number: Int) -> Int {
    print("Hello world from Swift: \(number)")
    return 69
}