java如何加载JNI。具有依赖项的动态库文件,但未获得未满足的链接错误?
目标:将Java链接到Swift
问题:在调用^{.dylib
文件链接的JNI.dylib
文件时,我得到一个^{
预期行为:将自动加载Java .dylib
的依赖项,或者对System.loadLibrary("SwiftCode")
的调用将加载依赖项(我能想到的唯一解决方案)
注意:我将this github tutorial和this Medium article组合起来创建我的JNI.dylib
文件和this tutorial来创建我的Swift.dylib
文件
完整堆栈跟踪:
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$NativeLibrary.loadLibrary(ClassLoader.java:2465)
at java.base/java.lang.ClassLoader.loadLibrary0(ClassLoader.java:2662)
at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2627)
at java.base/java.lang.Runtime.loadLibrary0(Runtime.java:829)
at java.base/java.lang.System.loadLibrary(System.java:1833)
at helloworld.SwiftHelloWorld.<clinit>(SwiftHelloWorld.java:7)
文件结构:
src
- helloworld
- SwiftHelloWorld.java
- native
- libSwiftHelloWorld.dylib
- libSwiftCode.dylib
MCVE:
SwiftHelloWorld.java
:
package helloworld;
public class SwiftHelloWorld {
static {
System.loadLibrary("SwiftCode"); // loading SwiftHelloWorld's dependency first
System.loadLibrary("SwiftHelloWorld"); // exception thrown here, can't find dependency?
}
public static native void printHelloWorldImpl();
public static void main(final String[] args) {
printHelloWorldImpl();
}
}
libSwiftHelloWorld.dylib
:使用以下两个终端命令创建:
export JAVA_HOME="$(/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
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
:从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
}
相关问题:
Java JNI linking multiple libraries,他/她得到一个
UnsatifiedLinkError
但描述为undefined symbol: ...
(未回答)任何带有
JNI
标记并包含UnsatifiedLinkError
其他注意事项:我正在将Java虚拟机的选项设置为-Djava.library.path=src/native
,这是两个.dylib
文件的父目录。我正在使用macOS
Edit:我尝试在命令前面使用xcrun
编译SwiftCode.swift
,如this article(在“编译Swift代码”下)中所示,但仍然得到相同的错误
# 1 楼答案
macOS
ld
将库依赖项的路径构建到二进制文件中。加载libSwiftHelloWorld.dylib
的加载程序只会在当前目录中找到libSwiftCode.dylib
。在Java中加载依赖项不起作用,因为对于加载程序来说,它是一个不同的库您可以使用
-install_name
参数(即swiftc ... -Xlinker -install_name -Xlinker <your path>
)更改libSwiftCode.dylib
的内置路径。如果之后重新生成libSwiftHelloWorld.dylib
,它将引用您提供的路径