JNI：NoSuchFieldError [英] JNI: NoSuchFieldError

问题描述

输出：javap的-s SomeClass的

Output of: javap -s SomeClass

public org.someapp.SomeClass$_data data;
  Signature: Lorg/someapp/SomeClass$_data;

SomeClass的Java中定义：

Definition of SomeClass in Java:

class SomeClass
{
    private class _data {
        byte[] something = new byte[1234];
    }

    public _data data;
}

本机功能的Java的定义：

Definition of native function in Java:

public static native int NativeFunction(SomeClass something);

Java实现的：

Java implementation:

SomeClass x = new SomeClass();
NativeInterface.NativeFunction(x);

然而，当下列code为执行：

However, when the following code is executed:

JNIEXPORT jint JNICALL Java_org_someapp_NativeInterface_NativeFunction(JNIEnv* env, jobject obj, jobject someobject) {
    jclass some_class = (*env)->GetObjectClass(env, someobject);
    jfieldID data = (*env)->GetFieldID(env, some_class, "data", "Lorg/someapp/SomeClass$_data"); 
}

Java的抛出的GetFieldID称之为NoSuchFieldError ;:数据异常。我不明白这一点。该签名是蛮好的（从javap的直接复制）。

Java throws a "NoSuchFieldError;: data" exception on the GetFieldID call. I don't get it.. The signature is just fine (copied straight from javap).

注意在获取ID字段为一个简单的变量，像一个无符号短（带标志性的S）的作品就好了。

Note that getting the field ID for a simpler variable, like an unsigned short (with signature "S") works just fine.

推荐答案

我有一种感觉，Lorg / someapp / SomeClass的$ _data应Lorg / someapp / SomeClass的$ _data;。注意分号。

I have a feeling that "Lorg/someapp/SomeClass$_data" should be "Lorg/someapp/SomeClass$_data;". Note the semicolon.

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