245 lines
6.8 KiB
Markdown
245 lines
6.8 KiB
Markdown
## 使用LTW(LoadTimeWeaving)技术实现AOP功能
|
||
|
||
### aop增强分类
|
||
|
||
###### 编译时：
|
||
|
||
使用特殊的编译器在编译期将切面织入目标类,这种比较少见,因为需要特殊的编译器的支持。例如，AspectJ编译 器，很少有到，目前我还没有用到。
|
||
|
||
###### 加载时：
|
||
|
||
通过字节码编辑技术在类加载期将切面织入目标类中,它的核心思想是：在目标类的class文件被JVM加 载前,通过自定义类加载器或者类文件转换器将横切逻辑织入到目标类的class文件中，然后将修改后class文件交给JVM加载 这种织入方式可以简称为LTW(LoadTimeWeaving)，AspectJ的LoadTimeWeaving (LTW)
|
||
|
||
###### 运行时：
|
||
|
||
运行期通过为目标类生成动态代理的方式实现AOP就属于运行期织入，这也是Spring AOP中的默认实现,并且提供了两种创建动态代理的方式：JDK自带的针对接口的动态代理和使用CGLib动态创建子类的方式创建动态代理。
|
||
|
||
|
||
|
||
### 优劣势
|
||
|
||
编译时：需要特殊的编译器
|
||
|
||
加载时：需要特殊的类加载器
|
||
|
||
运行时：功能有限
|
||
|
||
|
||
|
||
### 使用LTW 切面第三方JAR 包（普通maven项目）
|
||
|
||
#### 配置文件
|
||
|
||
##### pom 文件
|
||
|
||
```xml
|
||
<?xml version="1.0" encoding="UTF-8"?>
|
||
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
|
||
<modelVersion>4.0.0</modelVersion>
|
||
<parent>
|
||
<groupId>cn.x47.blog</groupId>
|
||
<artifactId>LoadTimeWeaving-demo</artifactId>
|
||
<version>1.0</version>
|
||
</parent>
|
||
|
||
<artifactId>java-aspectj-agent</artifactId>
|
||
<version>1.0</version>
|
||
<packaging>jar</packaging>
|
||
|
||
<dependencies>
|
||
<dependency>
|
||
<groupId>com.alibaba</groupId>
|
||
<artifactId>fastjson</artifactId>
|
||
</dependency>
|
||
<dependency>
|
||
<groupId>org.aspectj</groupId>
|
||
<artifactId>aspectjweaver</artifactId>
|
||
</dependency>
|
||
</dependencies>
|
||
<build>
|
||
<plugins>
|
||
<plugin>
|
||
<artifactId>maven-compiler-plugin</artifactId>
|
||
<version>2.3.2</version>
|
||
<configuration>
|
||
<source>1.8</source>
|
||
<target>1.8</target>
|
||
</configuration>
|
||
</plugin>
|
||
<plugin>
|
||
<artifactId>maven-assembly-plugin</artifactId>
|
||
<configuration>
|
||
<descriptorRefs>
|
||
<descriptorRef>jar-with-dependencies</descriptorRef>
|
||
</descriptorRefs>
|
||
<archive>
|
||
<manifest>
|
||
<mainClass>cn.x47.ltw.Main</mainClass><!--这里改成自己的主类位置-->
|
||
</manifest>
|
||
</archive>
|
||
</configuration>
|
||
<executions>
|
||
<execution>
|
||
<id>make-assembly</id>
|
||
<phase>package</phase>
|
||
<goals>
|
||
<goal>single</goal>
|
||
</goals>
|
||
</execution>
|
||
</executions>
|
||
</plugin>
|
||
</plugins>
|
||
</build>
|
||
</project>
|
||
|
||
```
|
||
|
||
|
||
|
||
##### aop.xml
|
||
|
||
放在`META-INF/aop.xml`
|
||
|
||
```xml
|
||
<!DOCTYPE aspectj PUBLIC "-//AspectJ//DTD//EN" "https://www.eclipse.org/aspectj/dtd/aspectj.dtd">
|
||
<aspectj>
|
||
<weaver>
|
||
<!-- 注意 目标类 和使用目标类方法的类都要配置 -->
|
||
<include within="cn.x47.ltw..*"/>
|
||
<include within="com.alibaba.fastjson.*"/>
|
||
</weaver>
|
||
<aspects>
|
||
<!-- 切面 -->
|
||
<aspect name="cn.x47.ltw.ProfilingAspect"/>
|
||
</aspects>
|
||
|
||
</aspectj>
|
||
```
|
||
|
||
|
||
|
||
### 目录结构
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
### 执行方法
|
||
|
||
##### 开发环境
|
||
|
||
可以通过添加jvm参数的方式来启动
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
### springboot 使用 LTW切面第三方JAR包
|
||
|
||
#### 配置文件
|
||
|
||
##### pom配置
|
||
|
||
```xml
|
||
<?xml version="1.0" encoding="UTF-8"?>
|
||
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
|
||
<modelVersion>4.0.0</modelVersion>
|
||
<parent>
|
||
<groupId>cn.x47.blog</groupId>
|
||
<artifactId>LoadTimeWeaving-demo</artifactId>
|
||
<version>1.0</version>
|
||
</parent>
|
||
|
||
<artifactId>springboot-aspectj-agent</artifactId>
|
||
<version>1.0</version>
|
||
<dependencies>
|
||
<dependency>
|
||
<groupId>org.springframework.boot</groupId>
|
||
<artifactId>spring-boot-starter</artifactId>
|
||
</dependency>
|
||
<dependency>
|
||
<groupId>org.springframework.boot</groupId>
|
||
<artifactId>spring-boot-starter-web</artifactId>
|
||
</dependency>
|
||
<dependency>
|
||
<groupId>com.alibaba</groupId>
|
||
<artifactId>fastjson</artifactId>
|
||
<version>2.0.12</version>
|
||
</dependency>
|
||
|
||
<dependency>
|
||
<groupId>org.springframework.boot</groupId>
|
||
<artifactId>spring-boot-starter-aop</artifactId>
|
||
</dependency>
|
||
|
||
<dependency>
|
||
<groupId>org.aspectj</groupId>
|
||
<artifactId>aspectjweaver</artifactId>
|
||
<version>1.9.9</version>
|
||
</dependency>
|
||
|
||
<dependency>
|
||
<groupId>org.projectlombok</groupId>
|
||
<artifactId>lombok</artifactId>
|
||
<optional>true</optional>
|
||
</dependency>
|
||
|
||
<dependency>
|
||
<groupId>org.springframework.boot</groupId>
|
||
<artifactId>spring-boot-starter-test</artifactId>
|
||
<scope>test</scope>
|
||
</dependency>
|
||
</dependencies>
|
||
|
||
<build>
|
||
<plugins>
|
||
<plugin>
|
||
<groupId>org.springframework.boot</groupId>
|
||
<artifactId>spring-boot-maven-plugin</artifactId>
|
||
</plugin>
|
||
</plugins>
|
||
</build>
|
||
|
||
</project>
|
||
```
|
||
|
||
|
||
|
||
##### oop配置
|
||
|
||
```xml
|
||
<?xml version="1.0" encoding="UTF-8" ?>
|
||
<aspectj>
|
||
<weaver options="-XnoInline -Xset:weaveJavaxPackages=true -Xlint:ignore -verbose -XmessageHandlerClass:org.springframework.aop.aspectj.AspectJWeaverMessageHandler">
|
||
<!--在编织时导入切面类和需要被切入的目标类-->
|
||
<include within="cn.x47.ltw..*"/>
|
||
<include within="com.alibaba.fastjson..*"/>
|
||
</weaver>
|
||
<aspects>
|
||
<!--指定切面类-->
|
||
<aspect name="cn.x47.ltw.springboot.aop.TestAspect"/>
|
||
</aspects>
|
||
</aspectj>
|
||
```
|
||
|
||
#### 目录结构
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
### 源码地址
|
||
|
||
https://git.dr1997.com/blog/LoadTimeWeaving-demo |