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dqzg12300 2023-04-16 22:59:59 +08:00
parent dfa7362039
commit 69475d8d88
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chapter-12/README.md
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@ -286,7 +286,7 @@ protected void onCreate(Bundle savedInstanceState) {
public final class DexFile {
...
@UnsupportedAppUsage
private static native void initConfig(PackageItem item);
private static native void initConfig(Object item);
}
```
@ -313,8 +313,8 @@ static JNINativeMethod gMethods[] = {
```c++
typedef struct{
char packageName[128];
char jniModuleName[1024];
char jniFuncName[1024];
char jniModuleName[128];
char jniFuncName[128];
bool isRegisterNativePrint;
bool isJNIMethodPrint;
bool jniEnable;
@ -341,10 +341,45 @@ class Runtime {
​ 这样在能访问到`Runtime`的任意地方都能获取到该配置了。现在就可以实现前面的`initConfig`函数了，将`java`传递过来的对象，转换为`c++`对象存储到`Runtime`中。具体实现如下。
```
```c++
static void
DexFile_initConfig(JNIEnv* env, jobject ,jobject item) {
Runtime* runtime=Runtime::Current();
// 将各字段取出
jclass jcInfo = env->FindClass("cn/krom/PackageItem");
jfieldID jPackageName = env->GetFieldID(jcInfo, "packageName", "Ljava/lang/String;");
jfieldID jJniModuleName = env->GetFieldID(jcInfo, "jniModuleName", "Ljava/lang/String;");
jfieldID jJniFuncName = env->GetFieldID(jcInfo, "jniFuncName", "Ljava/lang/String;");
jfieldID jIsRegisterNativePrint = env->GetFieldID(jcInfo, "isRegisterNativePrint", "Z");
jfieldID jIsJNIMethodPrint = env->GetFieldID(jcInfo, "isJNIMethodPrint", "Z");
PackageItem citem;
// 将java的值转换为c++的值
jstring jstrPackageName = (jstring)env->GetObjectField(item, jPackageName);
const char* pPackageName = (char*)env->GetStringUTFChars(jstrPackageName, 0);
strcpy(citem.packageName, pPackageName);
jstring jstrJniModuleName = (jstring)env->GetObjectField(item, jJniModuleName);
const char* pJniModuleName = (char*)env->GetStringUTFChars(jstrJniModuleName, 0);
strcpy(citem.jniModuleName, pJniModuleName);
jstring jstrJniFuncName = (jstring)env->GetObjectField(item, jJniFuncName);
const char* pJniFuncName = (char*)env->GetStringUTFChars(jstrJniFuncName, 0);
strcpy(citem.jniFuncName, pJniFuncName);
citem.isRegisterNativePrint = env->GetBooleanField(item, jIsRegisterNativePrint);
citem.isJNIMethodPrint = env->GetBooleanField(item, jIsJNIMethodPrint);
// 配置存储到全局
runtime->SetConfigItem(citem);
}
```
​ 到这里就成功从配置文件中读取数据，并解析后通过`native`函数将其存储到全局能访问的位置了。
## 12.4 JNI调用分析