Question

我正在尝试从c＆gt; java调用，以打开一个URL（即启动Web浏览器）。我在java中使用代码来启动url（这是我主要活动的一种方法）。当我刚刚在同一个线程上进行调用时，它工作正常，因为我已经从另一个线程调用了它，它已经坏了。

09-10 15:59:49.405: W/dalvikvm(31430): JNI WARNING: threadid=11 using env from threadid=1
09-10 15:59:49.405: E/dalvikvm(31430): JNI ERROR: env->self != thread-self (0x12988 vs. 0x200fb0); auto-correcting
09-10 15:59:49.405: W/dalvikvm(31430): JNI WARNING: threadid=11 using env from threadid=1
09-10 15:59:49.405: W/dalvikvm(31430): JNI WARNING: 0x41578910 is not a valid JNI reference
09-10 15:59:49.405: W/dalvikvm(31430):              in Lcom/mrqwak/app/AppRenderer;.onDrawFrameN:()V (CallVoidMethodV)
09-10 15:59:49.415: I/dalvikvm(31430): "GLThread 876" prio=5 tid=11 RUNNABLE
09-10 15:59:49.415: I/dalvikvm(31430):   | group="main" sCount=0 dsCount=0 obj=0x4157b270 self=0x200fb0
09-10 15:59:49.415: I/dalvikvm(31430):   | sysTid=31443 nice=0 sched=0/0 cgrp=default handle=1986128
09-10 15:59:49.420: I/dalvikvm(31430):   | schedstat=( 1035202257 457143963 4029 ) utm=80 stm=23 core=0
09-10 15:59:49.420: I/dalvikvm(31430):   at com.mrqwak.app.AppRenderer.onDrawFrameN(Native Method)
09-10 15:59:49.420: I/dalvikvm(31430):   at com.mrqwak.app.AppRenderer.onDrawFrame(AppActivity.java:289)
09-10 15:59:49.425: I/dalvikvm(31430):   at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1462)
09-10 15:59:49.425: I/dalvikvm(31430):   at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1216)
09-10 15:59:49.425: E/dalvikvm(31430): VM aborting
09-10 15:59:49.430: A/libc(31430): Fatal signal 11 (SIGSEGV) at 0xdeadd00d (code=1)

这是我的c代码：http://pastie.org/4696207

我在主UI线程上从c＆gt; java调用此函数，因为创建了主要活动：

JNIEnv*     g_envApp            =   0;
jobject     g_objApp            =   0;
jclass      g_classApp          =   0;
jmethodID   g_methodOpenURL     =   0;

JNIEXPORT void JNICALL Java_com_mrqwak_app_AppActivity_onCreateN(JNIEnv *env, jobject obj)
{
    g_envApp = env;
    g_objApp = obj;
    g_classApp = env->GetObjectClass(obj);
    if (g_classApp)
    {
        g_methodOpenURL = env->GetMethodID(g_classApp,"openURL","(Ljava/lang/String;)V");
    }
}

我稍后会在c> gt java中调用此函数，而不是在主UI上，当用户按下按钮打开网址时

extern  JNIEnv*     g_envApp;
extern  jobject     g_objApp;
extern  jclass      g_classApp;
extern  jmethodID   g_methodOpenURL;

void cHTTP::OpenURL(const char* psURL)
{
    if (g_methodOpenURL)
    {
        jstring jstr = g_envApp->NewStringUTF(psURL);
        g_envApp->CallVoidMethod(g_objApp,g_methodOpenURL,jstr);
    }
}

谢谢，

Answer 1

我相信你需要附加到UI线程 - jobjects不能跨线程共享 - 这就是这个：

JNIEnv *env;
jvm->AttachCurrentThread(&env, 0);
jmethodID mid = env->GetMethodID(g_classApp, "openURL", "(Ljava/lang/string)V");
env->CallVoidMethod(g_objApp, mid, url);

在第一次调用JNI时，在那里设置其他变量，添加一个jvm对象：

JavaVM  *jvm;
...
env->GetJavaVM(&jvm);

跨越不同的线程调用c＆gt; java

1 个答案: