如何在类路径中放置javaagent的类 [英] How to put classes for javaagent in the classpath

问题描述

我正在尝试开发一个javaagent，它可以在asm-4的帮助下检测代码。现在我遇到了一个非常基本的问题，javaagent的类加载器没有看到asm依赖，因此失败了。我是否必须提供一个jar-with-dependencies（又名maven build plugin），其中包含代理程序所需的所有类，或者是否有另一种方法将类添加到java代理程序中？
直接在类路径中引用jar asm-all.jar没有帮助。
构建jar-with-dependencies最初没有帮助，因为无法使用程序集插件设置Premain-Class属性。
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I am trying to develop a javaagent that would instrument code with help of asm-4. For now I'm stucked with a pretty basic problem, the classloader for the javaagent doesn't see asm dependencies and therefor fails. Do I have to provide a jar-with-dependencies (aka maven build plugin) which contains all the needed classes by the agent, or is there another way to add classes to the java agent? Referencing the jar asm-all.jar directly in the classpath didn't help. Building jar-with-dependencies didn't help at first, because Premain-Class attribute couldn't be set with assembly plugin. Help is appreciated ;-)

推荐答案

好的，通过实验找到它。
依赖类应该是jar的一部分，可以通过maven程序集插件创建，例如：

ok, found it by experimenting. The dependent classes should be part of the jar, which can be created by maven assembly plugin, for example:

    <plugin>
        <artifactId>maven-assembly-plugin</artifactId>
        <version>2.2</version>
        <configuration>
            <descriptorRefs>
                <descriptorRef>jar-with-dependencies</descriptorRef>
            </descriptorRefs>
            <archive>
                <index>true</index>
                <manifest>
                    <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                    <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
                </manifest>
                <manifestEntries>
                    <Premain-Class>test.agent.MyAgent</Premain-Class>
                </manifestEntries>
            </archive>
        </configuration>
        <executions>
            <execution>
                <id>make-assembly</id>
                <!-- this is used for inheritance merges -->
                <phase>package</phase>
                <!-- append to the packaging phase. -->
                <goals>
                    <goal>single</goal>
                    <!-- goals == mojos -->
                </goals>
            </execution>
        </executions>
    </plugin>

使用jar作为javaagent路径，一切正常。

Use the jar as javaagent path and everything works fine.

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