diff --git a/build.gradle.kts b/build.gradle.kts
index bb20375bc..17e6e1fe9 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -66,6 +66,9 @@ allprojects {
 }
 
 subprojects {
+    if (this@subprojects.name == "java-test") {
+        return@subprojects
+    }
     afterEvaluate {
         apply(plugin = "com.github.johnrengelman.shadow")
         val kotlin =
diff --git a/java-test/build.gradle.kts b/java-test/build.gradle.kts
new file mode 100644
index 000000000..6ec4dfaa9
--- /dev/null
+++ b/java-test/build.gradle.kts
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2020 Mamoe Technologies and contributors.
+ * 此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ * Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ * https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+
+plugins {
+    java
+}
+
+
+dependencies {
+
+    implementation(project(":mirai-core"))
+
+    implementation(project(":mirai-serialization"))
+
+    testImplementation(group = "junit", name = "junit", version = "4.12")
+
+    implementation(kotlin("stdlib", null))
+    implementation(kotlin("serialization", null))
+    implementation(kotlin("reflect", null))
+
+
+    implementation(kotlinx("serialization-runtime-common", Versions.Kotlin.serialization))
+    implementation(kotlinx("serialization-protobuf-common", Versions.Kotlin.serialization))
+    implementation(kotlinx("io", Versions.Kotlin.io))
+    implementation(kotlinx("coroutines-io", Versions.Kotlin.coroutinesIo))
+    implementation(kotlinx("coroutines-core-common", Versions.Kotlin.coroutines))
+
+    implementation("org.jetbrains.kotlinx:atomicfu-common:${Versions.Kotlin.atomicFU}")
+
+    implementation(ktor("client-cio", Versions.Kotlin.ktor))
+    implementation(ktor("client-core", Versions.Kotlin.ktor))
+    implementation(ktor("network", Versions.Kotlin.ktor))
+
+}
diff --git a/java-test/src/test/java/net/mamoe/mirai/javatest/SimpleListenerHostTest.java b/java-test/src/test/java/net/mamoe/mirai/javatest/SimpleListenerHostTest.java
new file mode 100644
index 000000000..80efb08ae
--- /dev/null
+++ b/java-test/src/test/java/net/mamoe/mirai/javatest/SimpleListenerHostTest.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2020 Mamoe Technologies and contributors.
+ * 此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ * Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ * https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+package net.mamoe.mirai.javatest;
+
+import kotlin.coroutines.CoroutineContext;
+import kotlin.coroutines.EmptyCoroutineContext;
+import kotlinx.coroutines.CoroutineScope;
+import kotlinx.coroutines.CoroutineScopeKt;
+import net.mamoe.mirai.event.*;
+import org.jetbrains.annotations.NotNull;
+import org.junit.Test;
+
+public class SimpleListenerHostTest {
+    @Test
+    public void test() {
+        final SimpleListenerHost host = new SimpleListenerHost() {
+            @EventHandler
+            public void testListen(
+                    AbstractEvent event
+            ) {
+                System.out.println(event);
+            }
+
+            @Override
+            public void handleException(@NotNull CoroutineContext context, @NotNull Throwable exception) {
+                exception.printStackTrace();
+            }
+        };
+        CoroutineScope scope = CoroutineScopeKt.CoroutineScope(EmptyCoroutineContext.INSTANCE);
+        Events.registerEvents(scope, host);
+        EventKt.broadcast(new AbstractEvent() {
+        });
+    }
+}
diff --git a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/event/JvmMethodListeners.kt b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/event/JvmMethodListeners.kt
index d5f715f6f..403710d35 100644
--- a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/event/JvmMethodListeners.kt
+++ b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/event/JvmMethodListeners.kt
@@ -331,9 +331,11 @@ private fun Method.registerEvent(
         }
     } else {
         // java methods
-
+        check(this.parameterCount == 1) {
+            "Illegal method parameter. Only one parameter is required."
+        }
         val paramType = this.parameters[0].type
-        check(this.parameterCount == 1 && Event::class.java.isAssignableFrom(paramType)) {
+        check(Event::class.java.isAssignableFrom(paramType)) {
             "Illegal method parameter. Required one exact Event subclass. found $paramType"
         }
         when (this.returnType) {
@@ -347,11 +349,11 @@ private fun Method.registerEvent(
                     if (annotation.ignoreCancelled) {
                         if ((this as? CancellableEvent)?.isCancelled != true) {
                             withContext(Dispatchers.IO) {
-                                this@registerEvent.invoke(owner, this)
+                                this@registerEvent.invoke(owner, this@subscribeAlways)
                             }
                         }
                     } else withContext(Dispatchers.IO) {
-                        this@registerEvent.invoke(owner, this)
+                        this@registerEvent.invoke(owner, this@subscribeAlways)
                     }
                 }
             }
@@ -365,11 +367,11 @@ private fun Method.registerEvent(
                     if (annotation.ignoreCancelled) {
                         if ((this as? CancellableEvent)?.isCancelled != true) {
                             withContext(Dispatchers.IO) {
-                                this@registerEvent.invoke(owner, this) as ListeningStatus
+                                this@registerEvent.invoke(owner, this@subscribe) as ListeningStatus
                             }
                         } else ListeningStatus.LISTENING
                     } else withContext(Dispatchers.IO) {
-                        this@registerEvent.invoke(owner, this) as ListeningStatus
+                        this@registerEvent.invoke(owner, this@subscribe) as ListeningStatus
                     }
 
                 }
diff --git a/settings.gradle b/settings.gradle
index ea22bf2c5..79f3e977b 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -24,6 +24,7 @@ rootProject.name = 'mirai'
 include(':mirai-core')
 include(':mirai-core-qqandroid')
 include(':mirai-serialization')
+include(':java-test')
 //include(':compatibility-validator') // THIS WILL CAUSE A DEPENDENCY RESOLUTION BUG
 //include(':java-compatibility-validator')