admin | 女足世界杯预测
如果我将 java 文件放在一个包中（如 jni/test/），执行时会出现致命错误。但是，如果我不将文件放在一个包中，一切都会正常工作。
有包裹时：
javac jni/test/Main.java
javah -jni jni.test.Main
g++ -shared -o libfoo.so -I/usr/lib/jvm/java-7-openjdk-i386/include -I/usr/lib/jvm/java-7-openjdk-i386/include/linux Main.cpp
java -Djava.library.path=. jni/test/Main
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0xb6c1ce3c, pid=3704, tid=3060386624
#
# JRE version: 7.0_25-b30
# Java VM: OpenJDK Server VM (23.7-b01 mixed mode linux-x86 )
# Problematic frame:
# V [libjvm.so+0x436e3c] get_method_id(JNIEnv_*, _jclass*, char const*, char const*, bool, Thread*) [clone .isra.106]+0x7c
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /home/idle/workspace/JNITest/src/hs_err_pid3704.log
#
# If you would like to submit a bug report, please include
# instructions on how to reproduce the bug and visit:
# https://bugs.launchpad.net/ubuntu/+source/openjdk-7/
#
Aborted
没有包裹时：
javac Main.java
javah -jni Main
g++ -shared -o libfoo.so -I/usr/lib/jvm/java-7-openjdk-i386/include -I/usr/lib/jvm/java-7-openjdk-i386/include/linux Main.cpp
java -Djava.library.path=. Main
//This executes fine
我有 2 个 java 类
public class Animal {
public String name = null;
public int age = 0;
}
public class Main {
public native Animal nativeFoo();
static {
System.loadLibrary("foo");
}
public void print () {
Animal a = nativeFoo();
System.out.println(a.name + " " + a.age);
}
public static void main(String[] args) {
(new Main()).print();
}
}
c++部分
/* DO NOT EDIT THIS FILE - it is machine generated */
#include
/* Header for class Main */
#ifndef _Included_Main
#define _Included_Main
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class: Main
* Method: nativeFoo
* Signature: ()LAnimal;
*/
//if the java file in a package
//JNIEXPORT jobject JNICALL Java_jni_test_Main_nativeFoo (JNIEnv *env, jobject obxj)
JNIEXPORT jobject JNICALL Java_Main_nativeFoo
(JNIEnv *, jobject);
#ifdef __cplusplus
}
#endif
#endif
.cpp 文件
#include "Main.h"
//if the java file in a package
//JNIEXPORT jobject JNICALL Java_jni_test_Main_nativeFoo (JNIEnv *env, jobject obxj)
JNIEXPORT jobject JNICALL Java_Main_nativeFoo (JNIEnv *env, jobject obxj){
jclass animal = env->FindClass("Animal");
jmethodID cons = env->GetMethodID(animal, "
jobject obj = env->NewObject(animal, cons);
jfieldID age = env->GetFieldID(animal, "age", "I");
jfieldID name = env->GetFieldID(animal, "name", "Ljava/lang/String;");
env->SetObjectField(obj, name, env->NewStringUTF("awww"));
env->SetIntField(obj, age, 23);
return obj;
}