Tencent/QMUI_Android · error · RuntimeException

Can not access the Class SchemeMapImpl. Please file a issue

Error message

Can not access the Class SchemeMapImpl. Please file a issue to report this.

What it means

QMUISchemeHandler's companion init reflectively instantiates the generated class SchemeMapImpl (produced by the arch-compiler SchemeProcessor). If Class.newInstance() raises IllegalAccessException — e.g. the class or its constructor is not accessible from the caller's classloader — the library wraps it in this RuntimeException and asks you to file an issue.

Source

Thrown at arch/src/main/java/com/qmuiteam/qmui/arch/scheme/QMUISchemeHandler.kt:47

        const val ARG_FINISH_CURRENT = "__qmui_finish_current"
        private var sSchemeMap: SchemeMap? = null

        init {
            try {
                val cls = Class.forName(SchemeMap::class.java.name + "Impl")
                sSchemeMap = cls.newInstance() as SchemeMap
            } catch (e: ClassNotFoundException) {
                sSchemeMap = object : SchemeMap {
                    override fun findScheme(handler: QMUISchemeHandler, schemeAction: String, params: Map<String, String>?): SchemeItem? {
                        return null
                    }

                    override fun exists(handler: QMUISchemeHandler, schemeAction: String): Boolean {
                        return false
                    }
                }
            } catch (e: IllegalAccessException) {
                throw RuntimeException(
                    "Can not access the Class SchemeMapImpl. " +
                            "Please file a issue to report this."
                )
            } catch (e: InstantiationException) {
                throw RuntimeException(
                    "Can not instance the Class SchemeMapImpl. " +
                            "Please file a issue to report this."
                )
            }
        }
    }

    val prefix: String = builder.prefix
    private var interpolatorList: List<QMUISchemeHandlerInterceptor> = builder.interceptorList
    private val blockSameSchemeTimeout = builder.blockSameSchemeTimeout
    val defaultIntentFactory = builder.defaultIntentFactory
    val defaultFragmentFactory = builder.defaultFragmentFactory
    val defaultSchemeMatcher = builder.defaultSchemeMatcher

View on GitHub (pinned to 026e7d4866)

Solutions

Add keep rules for the generated class: -keep class **.SchemeMapImpl { public <init>(); } (or keep com.qmuiteam.qmui.arch.scheme.**).
Verify kapt/annotationProcessor (arch-compiler) is configured so SchemeMapImpl is actually generated at compile time.
Check the generated SchemeMapImpl source (build/generated) and ensure the class and constructor are public.
If the class exists, is public, and keep rules are present, report the issue to the QMUI Android repository as the message suggests.

Example fix

// before (proguard-rules.pro)
# no rule -> SchemeMapImpl stripped

// after
-keep class com.qmuiteam.qmui.arch.scheme.SchemeMapImpl { *; }

Defensive patterns

Strategy: try-catch

Validate before calling

try {
    Class.forName("com.qmuiteam.qmui.arch.scheme.SchemeMapImpl")
} catch (e: Throwable) {
    Log.e(TAG, "SchemeMapImpl missing/inaccessible — check kapt + proguard rules", e)
}

Type guard

fun isSchemeMapAvailable(): Boolean = runCatching {
    Class.forName("com.qmuiteam.qmui.arch.scheme.SchemeMapImpl").constructors.any { it.parameterTypes.isEmpty() }
}.getOrDefault(false)

Try / catch

val intent = try {
    QMUISchemeHandler.instance.handle(uri)
} catch (e: RuntimeException) {
    if (e.message?.contains("Can not access the Class SchemeMapImpl") == true) {
        Log.e(TAG, "scheme init failed: keep rules / kapt missing", e)
        null
    } else throw e
}

Prevention

Add -keep rules for SchemeMapImpl and com.qmuiteam.qmui.arch.scheme.** in release builds
Always apply arch-compiler via kapt/annotationProcessor in modules using @Scheme* annotations
Smoke-test scheme handling in a minified release build, not only debug
Keep arch and arch-compiler on the same version

When it happens

Trigger: First access to QMUISchemeHandler (its public init/companion) when annotation processing failed to generate SchemeMapImpl correctly, or the generated class/constructor is not public, or R8/ProGuard stripped or renamed SchemeMapImpl so reflection cannot access it.

Common situations: ProGuard/R8 keep-rule missing for com.qmuiteam.qmui.arch.scheme.SchemeMapImpl in a minified release build; annotation processor not applied so a stale/inaccessible generated class exists; multi-dex/classloader edge cases.

Related errors

AI-assisted analysis of Tencent/QMUI_Android@026e7d4866 (2026-09-06). Data as JSON: /api/errors/7e3316c5d1a52968. Report an issue: GitHub.