API Exception Handling

Exceptions are the main problems often encountered in the development process. Here are some common exceptions that may be encountered during the use of YukiReflection and how to deal with them.

The exception description here will only synchronize the latest API version, and the exception of the older API version will not be described again, please always keep the API version up-to-date.

Non-Blocking Exceptions

These exceptions will not cause the app to stop running (FC), but will print E level logs on the console, and may also stop continuing to execute related functions.

exception

loggerE

Method/Constructor/Field match type "TYPE" not allowed

Abnormal

A disallowed parameter type was set when looking up methods, constructors, and variables.

The following example

// Find a method
method {
    //  Invalid type example is set
    param(false, 1, 0)
    //  Invalid type example is set
    returnType = false
}

// Find a variable
field {
    //  Invalid type example is set
    type = false
}

Solution

In the search, param, returnType, type only accept Class, String, VariousClass types, and parameter instances cannot be passed in.

The following example

// Find a method
method {
    // ✅ Examples of correct usage
    param(BooleanType, IntType, IntType)
    // ✅ Examples of correct usage
    returnType = BooleanType
    // ✅ The following scheme is also correct
    returnType = "java.lang.Boolean"
}

// Find a variable
field {
    // ✅ Examples of correct usage
    type = BooleanType
}

exception

loggerE

NoSuchMethod/NoSuchConstructor/NoSuchField happend in [NAME]

Abnormal

The target method, constructor, and variable were not found when looking for methods, constructors, and variables.

Solution

Please confirm that your search criteria can correctly match the specified methods, constructors and variables in the target Class.

exception

loggerE

Trying COUNT times and all failure by RemedyPlan

Abnormal

When using RemedyPlan to search for methods, constructors, and variables, the methods, constructors, and variables are still not found.

Solution

Please confirm the RemedyPlan parameter you set and the Class that exists in the current app, and try again.

exception

loggerE

Can't find this Class in [CLASSLOADER]: CONTENT Generated by YukiReflection#ReflectionTool

Abnormal

The Class object to be searched for was not found via ClassLoader.searchClass.

The following example

customClassLoader?.searchClass {
    from(...)
    // ...
}.get()

Solution

This is a security exception, please check the conditions you set, use the relevant tools to view the Class and bytecode object characteristics in the Dex and try again.

exception

loggerE

Can't find this Method/Constructor/Field in [CLASS]: CONTENT Generated by YukiReflection#ReflectionTool

Abnormal

The methods, constructors, and variables that need to be found cannot be found by specifying conditions.

The following example

TargetClass.method {
    name = "test"
    param(BooleanType)
}

Solution

This is a security exception, please check the conditions you set, use the relevant tools to view the bytecode object characteristics in the Class, and try again.

exception

loggerE

The number of VagueType must be at least less than the count of paramTypes

Abnormal

Incorrect use of VagueType in Method, Constructor lookup conditions.

The following example

TargetClass.method {
    name = "test"
    // <Scenario 1>
    param(VagueType)
    // <Scenario 2>
    param(VagueType, VagueType ...)
}

Solution

VagueType cannot be completely filled in method and constructor parameters. If there is such a requirement, please use paramCount.

exception

loggerE

Field match type class is not found

Abnormal

An instance of Class for type was not found in the lookup criteria set when looking up the variable.

The following example

field {
    name = "test"
    // Assume that the Class of the type set here does not exist
    type = "com.example.TestClass"
}

Solution

Please check if Class of type in the lookup condition exists and try again.

exception

loggerE

Method match returnType class is not found

Abnormal

An instance of Class of returnType was not found in the search criteria set when looking up the method.

The following example

method {
    name = "test"
    // Assume that the Class of returnType set here does not exist
    returnType = "com.example.TestClass"
}

Solution

Please check if Class of returnType in the lookup condition exists and try again.

exception

loggerE

Method/Constructor match paramType[INDEX] class is not found

Abnormal

The Class instance subscripted by the index number of param was not found in the search conditions set when searching for methods and constructors.

method {
    name = "test"
    // Assume that the Class with subscript "No.1" set here does not exist
    param(StringClass, "com.example.TestClass", BooleanType)
}

Solution

Please check if the Class subscripted by the index number of param in the lookup condition exists and try again.

Blocking Exceptions

These exceptions will directly cause the app to stop running (FC), at the same time print E level logs on the console.

exception

NoClassDefFoundError

Can't find this Class in [CLASSLOADER]: CONTENT Generated by YukiReflection#ReflectionTool

Abnormal

The Class object you were looking for was not found via String.toClass(...) or classOf<...>().

The following example

"com.demo.Test".toClass()

Solution

Please check if the Class matched by the current string or entity exists in the current ClassLoader and try again.

exception

IllegalStateException

ClassLoader [CLASSLOADER] is not a DexClassLoader

Abnormal

Use ClassLoader.searchClass to find Class but currently ClassLoader does not extends BaseDexClassLoader.

Solution

This situation basically does not exist, unless the current app references a Non-ART platform executable (which not realistic) or the current ClassLoader is null.

exception

IllegalStateException

VariousClass match failed of those CLASSES

Abnormal

All Class were not found when creating indeterminate Class objects using VariousClass.

Solution

After checking whether there is a matching Class in the current app and try again.

exception

IllegalStateException

paramTypes is empty, please use emptyParam() instead

Abnormal

The empty param method is preserved when looking up methods, constructors.

The following example

method {
    name = "test"
    // No parameters are filled in parentheses
    param()
}

Solution

To identify this method, the constructor has no parameters, you can have a setter method as follows.

The first way, set emptyParam (recommended)

The following example

method {
    name = "test"
    emptyParam()
}

The second way, set paramCount = 0

The following example

method {
    name = "test"
    paramCount = 0
}

exception

IllegalStateException

Cannot create classes cache for "android", please remove "name" param

Abnormal

The DexClassFinder cache function searchClass(name = ...) is used in the System Framework ("android") app.

The following example

searchClass(name = "test") {
    from(...)
    // ...
}.get()

Solution

Since the cache will store the found Class name in SharedPreferences, but the data directory does not exist in the System Framework, so please do not use this function in the System Framework.

exception

IllegalStateException

Target Class type cannot cast to TYPE

Abnormal

Wrong type declared when converting string class name to target Class using Class.toClass, Class.toClassOrNull, GenericClass.argument methods.

The following uses the Class.toClass method as an example.

The following example

// Assume the target type is Activity but it was wrongly cast to WrongClass type
val clazz = "android.app.Activity".toClass<WrongClass>()

Solution

The following example

// <Solution 1> Fill in the correct type
val clazz1 = "android.app.Activity".toClass<Activity>()
// <Solution 2> Do not fill in the generic declaration
val clazz2 = "android.app.Activity".toClass()

Please ensure that the generic type declared after executing the method is the specified target Class type, and you do not need to fill in the generic declaration if the target type is not sure.