ReflectASM高性能反射Java库

逃离我推掉我的手 2023-10-09 16:26 4阅读 0赞

##### 1. 简介 #####

在日常开发中，经常需要使用反射操作类中的属性或方法。ReflectASM是一个非常小的 Java 库，它提供高性能反射能力。  
  Github地址：[https://github.com/EsotericSoftware/reflectasm][https_github.com_EsotericSoftware_reflectasm]

##### 2. 官方性能报告 #####

![4609cd30e716d2ffffdd3ba8b9ff9173.png][]![b739aea0927210ebb2539bb7d3df1bcb.png][]![0e35dde375dd2ed1ed3f4ddc7fef0579.png][]

##### 3. 用法 #####

ReflectASM仅可访问public属性和方法。

*  pom引入依赖

<dependency>
        <groupId>com.esotericsoftware</groupId>
        <artifactId>reflectasm</artifactId>
        <version>{latest.version}</version>
    </dependency>

*  使用 ReflectASM 的构造函数反射：

ConstructorAccess<User> constructorAccess = ConstructorAccess.get(User.class);
    User user = constructorAccess.newInstance();

*  使用 ReflectASM 的属性反射：

User user = new User();
    FieldAccess fieldAccess = FieldAccess.get(User.class);
    fieldAccess.set(user, "username", "张三");
    String name = (String) fieldAccess.get(user, "username");

*  使用 ReflectASM 的方法反射：

User user = new User();
    MethodAccess methodAccess = MethodAccess.get(User.class);
    methodAccess.invoke(user, "setUserame", "张三");
    String username = (String) methodAccess.invoke(user, "getUsername");

*  使用 ReflectASM 的属性索引反射(推荐)：

User user = new User();
    FieldAccess fieldAccess = FieldAccess.get(User.class);
    int index = fieldAccess.getIndex("username");
    fieldAccess.set(user, index, "张三");
    String username = (String) fieldAccess.get(user, index);

*  使用 ReflectASM 的方法索引反射(推荐)：

User user = new User();
    MethodAccess methodAccess = MethodAccess.get(User.class);
    int setIndex = methodAccess.getIndex("setUserame");
    int getIndex = methodAccess.getIndex("getUsername");
    methodAccess.invoke(user, setIndex, "张三"
    String username = (String) methodAccess.invoke(user, getIndex);

##### 4. 单元测试 #####

import com.esotericsoftware.reflectasm.ConstructorAccess;
    import com.esotericsoftware.reflectasm.FieldAccess;
    import com.esotericsoftware.reflectasm.MethodAccess;
    import lombok.extern.slf4j.Slf4j;
    import org.junit.jupiter.api.Test;
    import org.springframework.util.StopWatch;
    
    import java.lang.reflect.Method;
    
    /**
     * 高性能反射Java库 单元测试
     *
     * @author CL
     */
    @Slf4j
    public class ReflectAsmTest {
    
        /**
         * 测试方案：循环 n 次，通过set方法设置值，然后通过get方法获取值<br/>
         */
        @Test
        public void test() throws Exception {
    //        final String FIELD_NAME = "username";
            final String SET_METHOD_NAME = "setUsername";
            final String GET_METHOD_NAME = "getUsername";
            // 次数
            int n = 1_0000;
    
            StopWatch stopWatch = new StopWatch();
    
            stopWatch.start("Java反射");
    
            Class<User> clazz = User.class;
    //        Field field = clazz.getDeclaredField(FIELD_NAME);
    //        field.setAccessible(true);
            Method setMethod = clazz.getDeclaredMethod(SET_METHOD_NAME, String.class);
            Method getmethod = clazz.getDeclaredMethod(GET_METHOD_NAME);
    
            for (int i = 1; i <= n; i++) {
                User user = clazz.newInstance();
    
                setMethod.invoke(user, "方法" + i);
    
                Object invoke = getmethod.invoke(user);
    //            log.debug("get值：{}", invoke);
            }
    
            stopWatch.stop();
    
            stopWatch.start("ReflectAsm反射");
    
            ConstructorAccess<User> constructorAccess = ConstructorAccess.get(User.class);
            FieldAccess fieldAccess = FieldAccess.get(User.class);
            MethodAccess methodAccess = MethodAccess.get(User.class);
    
            for (int i = 1; i <= n; i++) {
                User user = constructorAccess.newInstance();
    
                methodAccess.invoke(user, SET_METHOD_NAME, "方法" + i);
    
                Object invoke = methodAccess.invoke(user, GET_METHOD_NAME);
    //            log.debug("get值：{}", invoke);
            }
    
            stopWatch.stop();
    
            stopWatch.start("ReflectAsm反射(优化)");
    
            int setIndex = methodAccess.getIndex(SET_METHOD_NAME);
            int getIndex = methodAccess.getIndex(GET_METHOD_NAME);
            for (int i = 1; i <= n; i++) {
                User user = constructorAccess.newInstance();
    
                methodAccess.invoke(user, setIndex, "方法" + i);
    
                Object invoke = methodAccess.invoke(user, getIndex);
    //            log.debug("get值：{}", invoke);
            }
    
            stopWatch.stop();
    
            for (StopWatch.TaskInfo taskInfo : stopWatch.getTaskInfo()) {
                log.info("{} 耗时：{} ms", taskInfo.getTaskName(), taskInfo.getTimeMillis());
            }
        }
        
    }
    
    class User {
    
        private String username;
    
        public User() {
        }
    
        public User(String username) {
            this.username = username;
        }
    
        public String getUsername() {
            return username;
        }
    
        public void setUsername(String username) {
            this.username = username;
        }
    
    }

100次循环单元测试结果：

23:54:37.630 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - Java反射 耗时：3 ms
    23:54:37.635 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - ReflectAsm反射 耗时：21 ms
    23:54:37.635 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - ReflectAsm反射(优化) 耗时：0 ms

1000次循环单元测试结果：

23:55:07.161 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - Java反射 耗时：7 ms
    23:55:07.168 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - ReflectAsm反射 耗时：35 ms
    23:55:07.168 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - ReflectAsm反射(优化) 耗时：1 ms

10000次循环单元测试结果：

23:55:27.604 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - Java反射 耗时：44 ms
    23:55:27.611 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - ReflectAsm反射 耗时：49 ms
    23:55:27.611 [main] INFO com.c3stones.reflectasm.ReflectAsmTest - ReflectAsm反射(优化) 耗时：7 ms

[https_github.com_EsotericSoftware_reflectasm]: https://github.com/EsotericSoftware/reflectasm
[4609cd30e716d2ffffdd3ba8b9ff9173.png]: https://img-blog.csdnimg.cn/img_convert/4609cd30e716d2ffffdd3ba8b9ff9173.png
[b739aea0927210ebb2539bb7d3df1bcb.png]: https://img-blog.csdnimg.cn/img_convert/b739aea0927210ebb2539bb7d3df1bcb.png
[0e35dde375dd2ed1ed3f4ddc7fef0579.png]: https://img-blog.csdnimg.cn/img_convert/0e35dde375dd2ed1ed3f4ddc7fef0579.png