JAVAlang.NoSuchFieldError:类“Ljava/lang/Integer”中没有“I”字段“value”或者它的超类Android 10

Question

我收到了一封信。所以我必须将客户端的安卓库集成到我的Xamarin表单项目中。该库帮助应用程序连接到物联网设备。由于库方法具有以下特征，我决定编写一个java包装器来简化参数并创建一个aar文件。之后，我以本机方式绑定aar，并将其用作项目中的dll

需要注意的是，Xamarin中的问题仅在编译目标为>；10.否则，它可以正常工作。我的猜测是latest Updates to non-SDK interfaces broke the application

库标题：

public static native int ReadParams(String token, StringBuilder serial, StringBuilder ssid, StringBuilder password, StringBuilder sensor, Integer keepAlive);

问题是： 当从本机安卓应用程序中调用该方法时，该方法工作正常，但是由于Xamarin表单中的以下错误而崩溃。崩溃在Java包装器的下面一行

紧急救援线：

StringBuilder strSerial = new StringBuilder();
StringBuilder strssid = new StringBuilder();
StringBuilder strpassword = new StringBuilder();
StringBuilder strsensor = new StringBuilder();
Integer keepAlive = new Integer(0);
//Crash on below line
int response = EPM002Lib.ReadParams(token, strSerial, strssid, strpassword, strsensor, keepAlive);

堆栈跟踪：

--- End of managed Java.Lang.IncompatibleClassChangeError stack trace --- java.lang.NoSuchFieldError: no "I" field "value" in class "Ljava/lang/Integer;" or its superclasses at com.esong.lib.EPM002Lib.ReadParams(Native Method) at com.sensorwa.config.configdemo.SquareSdkhelper.ReadParams(SquareSdkhelper.java:32)

我了解更多关于EPM002Lib内部功能的信息。ReadParams-params会有所帮助，但是，该库似乎可以与本机安卓应用程序一起使用（即使是在针对安卓 10编译时）。请随时询问更多信息或提供建议。谢谢你的帮助😄

Answer 1

您依赖的是一个不应该依赖的实现细节

现在它坏了，你可以保留这两部分

Answer 2

我使用Android Aarch64编译器编译了此文件：

#include <jni.h>

int access_field(JNIEnv *env, jobject obj) {
    jclass cls_Integer = (*env)->FindClass(env, "Ljava/lang/Integer;");
    jfieldID fid_Integer_value = (*env)->GetFieldID(env, cls_Integer, "value", "I");
    return (*env)->GetIntField(env, obj, fid_Integer_value);
}

int access_method(JNIEnv *env, jobject obj) {
    jclass cls_Integer = (*env)->FindClass(env, "Ljava/lang/Integer;");
    jmethodID mid_Integer_value = (*env)->GetMethodID(env, cls_Integer, "intValue", "()I");
    return (*env)->CallIntMethod(env, obj, mid_Integer_value);
}

这将为access_field生成以下代码：

int access_field(JNIEnv *env, jobject obj) {
   0:   d10103ff    sub sp, sp, #0x40
   4:   a9037bfd    stp x29, x30, [sp,#48]
   8:   9100c3fd    add x29, sp, #0x30
   c:   90000008    adrp    x8, 0 <access_field>
  10:   91000108    add x8, x8, #0x0
  14:   90000002    adrp    x2, 0 <access_field>
  18:   91000042    add x2, x2, #0x0
  1c:   90000003    adrp    x3, 0 <access_field>
  20:   91000063    add x3, x3, #0x0
  24:   f81f83a0    stur    x0, [x29,#-8]
  28:   f81f03a1    stur    x1, [x29,#-16]
    jclass cls_Integer = (*env)->FindClass(env, "Ljava/lang/Integer;");
  2c:   f85f83a9    ldur    x9, [x29,#-8]
  30:   f9400129    ldr x9, [x9]
  34:   f9401929    ldr x9, [x9,#48]
  38:   f85f83a0    ldur    x0, [x29,#-8]
  3c:   aa0803e1    mov x1, x8
  40:   f90007e2    str x2, [sp,#8]
  44:   f90003e3    str x3, [sp]
  48:   d63f0120    blr x9
  4c:   f9000fe0    str x0, [sp,#24]
    jfieldID fid_Integer_value = (*env)->GetFieldID(env, cls_Integer, "value", "I");
  50:   f85f83a8    ldur    x8, [x29,#-8]
  54:   f9400108    ldr x8, [x8]
  58:   f9417908    ldr x8, [x8,#752]
  5c:   f85f83a0    ldur    x0, [x29,#-8]
  60:   f9400fe1    ldr x1, [sp,#24]
  64:   f94007e2    ldr x2, [sp,#8]
  68:   f94003e3    ldr x3, [sp]
  6c:   d63f0100    blr x8
  70:   f9000be0    str x0, [sp,#16]
    return (*env)->GetIntField(env, obj, fid_Integer_value);
  74:   f85f83a8    ldur    x8, [x29,#-8]
  78:   f9400108    ldr x8, [x8]
  7c:   f9419108    ldr x8, [x8,#800]
  80:   f85f83a0    ldur    x0, [x29,#-8]
  84:   f85f03a1    ldur    x1, [x29,#-16]
  88:   f9400be2    ldr x2, [sp,#16]
  8c:   d63f0100    blr x8
  90:   a9437bfd    ldp x29, x30, [sp,#48]
  94:   910103ff    add sp, sp, #0x40
  98:   d65f03c0    ret


}

对于access_method而言：

int access_method(JNIEnv *env, jobject obj) {
  9c:   d10103ff    sub sp, sp, #0x40
  a0:   a9037bfd    stp x29, x30, [sp,#48]
  a4:   9100c3fd    add x29, sp, #0x30
  a8:   90000008    adrp    x8, 0 <access_field>
  ac:   91000108    add x8, x8, #0x0
  b0:   90000002    adrp    x2, 0 <access_field>
  b4:   91000042    add x2, x2, #0x0
  b8:   90000003    adrp    x3, 0 <access_field>
  bc:   91000063    add x3, x3, #0x0
  c0:   f81f83a0    stur    x0, [x29,#-8]
  c4:   f81f03a1    stur    x1, [x29,#-16]
    jclass cls_Integer = (*env)->FindClass(env, "Ljava/lang/Integer;");
  c8:   f85f83a9    ldur    x9, [x29,#-8]
  cc:   f9400129    ldr x9, [x9]
  d0:   f9401929    ldr x9, [x9,#48]
  d4:   f85f83a0    ldur    x0, [x29,#-8]
  d8:   aa0803e1    mov x1, x8
  dc:   f90007e2    str x2, [sp,#8]
  e0:   f90003e3    str x3, [sp]
  e4:   d63f0120    blr x9
  e8:   f9000fe0    str x0, [sp,#24]
    jmethodID mid_Integer_value = (*env)->GetMethodID(env, cls_Integer, "intValue", "()I");
  ec:   f85f83a8    ldur    x8, [x29,#-8]
  f0:   f9400108    ldr x8, [x8]
  f4:   f9408508    ldr x8, [x8,#264]
  f8:   f85f83a0    ldur    x0, [x29,#-8]
  fc:   f9400fe1    ldr x1, [sp,#24]
 100:   f94007e2    ldr x2, [sp,#8]
 104:   f94003e3    ldr x3, [sp]
 108:   d63f0100    blr x8
 10c:   f9000be0    str x0, [sp,#16]
    return (*env)->CallIntMethod(env, obj, mid_Integer_value);
 110:   f85f83a8    ldur    x8, [x29,#-8]
 114:   f9400108    ldr x8, [x8]
 118:   f940c508    ldr x8, [x8,#392]
 11c:   f85f83a0    ldur    x0, [x29,#-8]
 120:   f85f03a1    ldur    x1, [x29,#-16]
 124:   f9400be2    ldr x2, [sp,#16]
 128:   d63f0100    blr x8
 12c:   a9437bfd    ldp x29, x30, [sp,#48]
 130:   910103ff    add sp, sp, #0x40
 134:   d65f03c0    ret

主要区别在于ldr x8调用中使用的偏移量。这些是JNIEnv中函数指针表的偏移量，更具体地说：

• GetFieldID位于偏移量752处
• GetIntField位于偏移量800处
• GetMethodID位于偏移量264处
• CallIntMethod位于偏移量392处

另一个区别是传递给GetIntField或GetMethodID的签名，该签名在链接器时被注入。我转储的对象文件尚未链接，因此那里有伪指令。它是第四个参数，因此在寄存器x3中传递

因此，总而言之，您需要执行以下操作：

• 在库中的某个位置查找字符串"()I"的地址或将其添加到字符串表中
• 您需要找到访问java.lang.Integer#value的所有位置
• 替换ldr x8调用前blr x8中的两个函数指针偏移量（752->；264；800->；392）
• 查找更改x3的代码，并将其改为指向"()I"

祝你好运