Try to optimize the interceptor

src/main/java/org/apache/ibatis/plugin/Invocation.java

@@ -35,14 +35,16 @@ public class Invocation {
   private final Object target;
   private final Method method;
   private final Object[] args;
+  private final List<Interceptor> interceptors;
 
-  public Invocation(Object target, Method method, Object[] args) {
+  public Invocation(Object target, Method method, Object[] args, List<Interceptor> interceptors) {
     if (!targetClasses.contains(method.getDeclaringClass())) {
       throw new IllegalArgumentException("Method '" + method + "' is not supported as a plugin target.");
     }
     this.target = target;
     this.method = method;
     this.args = args;
+    this.interceptors = interceptors;
   }
 
   public Object getTarget() {
@@ -57,8 +59,14 @@ public Object[] getArgs() {
     return args;
   }
 
-  public Object proceed() throws InvocationTargetException, IllegalAccessException {
-    return method.invoke(target, args);
+  public Object proceed() throws Throwable {
+    int intSize = interceptors.size();
+    if ((intSize --)== 0) {
+      return method.invoke(target, args);
+    }
+    Interceptor interceptor = interceptors.get(intSize);
+    return interceptor.intercept(this);
+
   }
 
 }

src/main/java/org/apache/ibatis/plugin/Plugin.java

@@ -18,52 +18,72 @@
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
-
 import org.apache.ibatis.reflection.ExceptionUtil;
-import org.apache.ibatis.util.MapUtil;
+
 
 /**
  * @author Clinton Begin
  */
 public class Plugin implements InvocationHandler {
 
   private final Object target;
-  private final Interceptor interceptor;
-  private final Map<Class<?>, Set<Method>> signatureMap;
+  private final Map<Method, List<Interceptor>> interceptorMap;
 
-  private Plugin(Object target, Interceptor interceptor, Map<Class<?>, Set<Method>> signatureMap) {
+  private Plugin(Object target, Map<Method, List<Interceptor>> interceptorMap) {
     this.target = target;
-    this.interceptor = interceptor;
-    this.signatureMap = signatureMap;
+    this.interceptorMap = interceptorMap;
+  }
+
+  public Map<Method, List<Interceptor>> getInterceptorMap() {
+    return interceptorMap;
   }
 
   public static Object wrap(Object target, Interceptor interceptor) {
     Map<Class<?>, Set<Method>> signatureMap = getSignatureMap(interceptor);
     Class<?> type = target.getClass();
     Class<?>[] interfaces = getAllInterfaces(type, signatureMap);
     if (interfaces.length > 0) {
-      return Proxy.newProxyInstance(type.getClassLoader(), interfaces, new Plugin(target, interceptor, signatureMap));
-    }
+      if (Proxy.isProxyClass(target.getClass())) {
+        InvocationHandler invocationHandler = Proxy.getInvocationHandler(target);
+        if (invocationHandler instanceof Plugin) {
+          Map<Method, List<Interceptor>> interceptorMap = ((Plugin) invocationHandler).getInterceptorMap();
+          mapping(interceptor, signatureMap, interceptorMap);
+          return target;
+        }
+      }
+
+      Map<Method, List<Interceptor>> interceptorMap = new HashMap<>();
+      mapping(interceptor, signatureMap, interceptorMap);
+      return Proxy.newProxyInstance(type.getClassLoader(), interfaces, new Plugin(target, interceptorMap));}
     return target;
   }
 
   @Override
   public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
     try {
-      Set<Method> methods = signatureMap.get(method.getDeclaringClass());
-      if (methods != null && methods.contains(method)) {
-        return interceptor.intercept(new Invocation(target, method, args));
-      }
+      List<Interceptor> interceptors = interceptorMap.get(method);
+      if (interceptors != null) {
+        return new Invocation(target, method, args, interceptors).proceed();}
       return method.invoke(target, args);
     } catch (Exception e) {
       throw ExceptionUtil.unwrapThrowable(e);
     }
   }
 
+  private static void mapping(Interceptor interceptor, Map<Class<?>, Set<Method>> signatureMap, Map<Method, List<Interceptor>> interceptorMap) {
+    for (Set<Method> methods : signatureMap.values()) {
+      for (Method method : methods) {
+        interceptorMap.computeIfAbsent(method, (key) -> new ArrayList<>()).add(interceptor);
+      }
+    }
+  }
+
   private static Map<Class<?>, Set<Method>> getSignatureMap(Interceptor interceptor) {
     Intercepts interceptsAnnotation = interceptor.getClass().getAnnotation(Intercepts.class);
     // issue #251
@@ -74,7 +94,7 @@ private static Map<Class<?>, Set<Method>> getSignatureMap(Interceptor intercepto
     Signature[] sigs = interceptsAnnotation.value();
     Map<Class<?>, Set<Method>> signatureMap = new HashMap<>();
     for (Signature sig : sigs) {
-      Set<Method> methods = MapUtil.computeIfAbsent(signatureMap, sig.type(), k -> new HashSet<>());
+      Set<Method> methods = signatureMap.computeIfAbsent(sig.type(), k -> new HashSet<>());
       try {
         Method method = sig.type().getMethod(sig.method(), sig.args());
         methods.add(method);

src/test/java/org/apache/ibatis/submitted/plugin_invocation/BaseTest.java

@@ -0,0 +1,65 @@
+/*
+ *    Copyright 2009-2023 the original author or authors.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *       https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+package org.apache.ibatis.submitted.plugin_invocation;
+
+import org.apache.ibatis.BaseDataTest;
+import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.session.SqlSession;
+import org.apache.ibatis.session.SqlSessionFactory;
+import org.apache.ibatis.session.SqlSessionFactoryBuilder;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.io.Reader;
+
+class BaseTest {
+
+  private static SqlSessionFactory sqlSessionFactory;
+
+  @BeforeAll
+  static void setUp() throws Exception {
+    // create an SqlSessionFactory
+    try (Reader reader = Resources.getResourceAsReader("org/apache/ibatis/submitted/plugin_invocation/mybatis-config.xml")) {
+      sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
+    }
+
+    // populate in-memory database
+    BaseDataTest.runScript(sqlSessionFactory.getConfiguration().getEnvironment().getDataSource(),
+        "org/apache/ibatis/submitted/plugin_invocation/CreateDB.sql");
+  }
+
+  @Test
+  void shouldGetAUser() {
+    try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      User user = mapper.getUser(1);
+      Assertions.assertEquals("User1", user.getName());
+    }
+  }
+
+  @Test
+  void shouldInsertAUser() {
+    try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      User user = new User();
+      user.setId(2);
+      user.setName("User2");
+      mapper.insertUser(user);
+    }
+  }
+
+}

src/test/java/org/apache/ibatis/submitted/plugin_invocation/Mapper.java

@@ -0,0 +1,24 @@
+/*
+ *    Copyright 2009-2022 the original author or authors.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *       https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+package org.apache.ibatis.submitted.plugin_invocation;
+
+public interface Mapper {
+
+  User getUser(Integer id);
+
+  void insertUser(User user);
+
+}

src/test/java/org/apache/ibatis/submitted/plugin_invocation/User.java

@@ -0,0 +1,38 @@
+/*
+ *    Copyright 2009-2022 the original author or authors.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *       https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+package org.apache.ibatis.submitted.plugin_invocation;
+
+public class User {
+
+  private Integer id;
+  private String name;
+
+  public Integer getId() {
+    return id;
+  }
+
+  public void setId(Integer id) {
+    this.id = id;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+}

src/test/resources/org/apache/ibatis/submitted/plugin_invocation/CreateDB.sql

@@ -0,0 +1,24 @@
+--
+--    Copyright 2009-2022 the original author or authors.
+--
+--    Licensed under the Apache License, Version 2.0 (the "License");
+--    you may not use this file except in compliance with the License.
+--    You may obtain a copy of the License at
+--
+--       https://www.apache.org/licenses/LICENSE-2.0
+--
+--    Unless required by applicable law or agreed to in writing, software
+--    distributed under the License is distributed on an "AS IS" BASIS,
+--    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+--    See the License for the specific language governing permissions and
+--    limitations under the License.
+--
+
+drop table users if exists;
+
+create table users (
+  id int,
+  name varchar(20)
+);
+
+insert into users (id, name) values(1, 'User1');

src/test/resources/org/apache/ibatis/submitted/plugin_invocation/Mapper.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+       Copyright 2009-2022 the original author or authors.
+
+       Licensed under the Apache License, Version 2.0 (the "License");
+       you may not use this file except in compliance with the License.
+       You may obtain a copy of the License at
+
+          https://www.apache.org/licenses/LICENSE-2.0
+
+       Unless required by applicable law or agreed to in writing, software
+       distributed under the License is distributed on an "AS IS" BASIS,
+       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+       See the License for the specific language governing permissions and
+       limitations under the License.
+
+-->
+<!DOCTYPE mapper
+    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+    "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
+
+<mapper namespace="org.apache.ibatis.submitted.plugin_invocation.Mapper">
+
+    <select id="getUser" resultType="org.apache.ibatis.submitted.plugin_invocation.User">
+        select * from users where id = #{id}
+    </select>
+
+    <insert id="insertUser">
+        insert into users values(#{id}, #{name})
+    </insert>
+
+</mapper>

src/test/resources/org/apache/ibatis/submitted/plugin_invocation/mybatis-config.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!--
+
+       Copyright 2009-2022 the original author or authors.
+
+       Licensed under the Apache License, Version 2.0 (the "License");
+       you may not use this file except in compliance with the License.
+       You may obtain a copy of the License at
+
+          https://www.apache.org/licenses/LICENSE-2.0
+
+       Unless required by applicable law or agreed to in writing, software
+       distributed under the License is distributed on an "AS IS" BASIS,
+       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+       See the License for the specific language governing permissions and
+       limitations under the License.
+
+-->
+<!DOCTYPE configuration
+    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
+    "https://mybatis.org/dtd/mybatis-3-config.dtd">
+
+<configuration>
+
+    <environments default="development">
+        <environment id="development">
+            <transactionManager type="JDBC">
+                <property name="" value="" />
+            </transactionManager>
+            <dataSource type="UNPOOLED">
+                <property name="driver" value="org.hsqldb.jdbcDriver" />
+                <property name="url" value="jdbc:hsqldb:mem:plugin_invocation" />
+                <property name="username" value="sa" />
+            </dataSource>
+        </environment>
+    </environments>
+
+    <mappers>
+        <mapper class="org.apache.ibatis.submitted.plugin_invocation.Mapper" />
+    </mappers>
+
+</configuration>