java - 使用 Maven 阴影重新定位包时 AmazonEc2Client 出现运行时错误

Question

我正在开发一个 java 代理，并使用 Maven Shade 插件来重新定位我的依赖项，这样我就可以避免类路径冲突和问题。到目前为止，我对阴影插件还不太熟悉，但我遇到了这个问题，我告诉插件对我的依赖项进行阴影处理，并在所有内容前面添加 shaded (例如 com.amazonaws.services .ec2 -> shaded.amazonaws.services.ec2)，但是，当我运行构建 AmazonEc2Client 的应用程序时，出现以下错误:

Caused by: shaded.com.amazonaws.AmazonClientException: Unable to instantiate request handler chain for client: com.amazonaws.services.ec2.model.transform.EC2RequestHandler
    at shaded.com.amazonaws.handlers.HandlerChainFactory.createRequestHandlerChain(HandlerChainFactory.java:158)
    at shaded.com.amazonaws.handlers.HandlerChainFactory.newRequestHandlerChain(HandlerChainFactory.java:45)
    at shaded.com.amazonaws.services.ec2.AmazonEC2Client.init(AmazonEC2Client.java:308)
    at shaded.com.amazonaws.services.ec2.AmazonEC2Client.<init>(AmazonEC2Client.java:297)
    at shaded.com.amazonaws.services.ec2.AmazonEC2Client.<init>(AmazonEC2Client.java:280)
    at shaded.com.amazonaws.services.ec2.AmazonEC2ClientBuilder.build(AmazonEC2ClientBuilder.java:61)
    at shaded.com.amazonaws.services.ec2.AmazonEC2ClientBuilder.build(AmazonEC2ClientBuilder.java:27)
    at shaded.com.amazonaws.client.builder.AwsSyncClientBuilder.build(AwsSyncClientBuilder.java:46)
    at my.sample.project.Boot.<clinit>(Boot.java:49)
    ... 6 more
Caused by: java.lang.ClassNotFoundException: com.amazonaws.services.ec2.model.transform.EC2RequestHandler
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at shaded.com.amazonaws.util.ClassLoaderHelper.loadClass(ClassLoaderHelper.java:177)
    at shaded.com.amazonaws.util.ClassLoaderHelper.loadClass(ClassLoaderHelper.java:136)
    at shaded.com.amazonaws.handlers.HandlerChainF

这是我的 pom.xml 的片段

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>3.0.0</version>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <transformers>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <manifestEntries>
                            <Premain-Class>my.sample.project.Boot</Premain-Class>
                        </manifestEntries>
                    </transformer>
                </transformers>
                <relocations>
                    <relocation>
                        <pattern>com.amazonaws</pattern>
                        <shadedPattern>shaded.com.amazonaws</shadedPattern>
                    </relocation>
                    <artifactSet>
                        <includes>
                            <include>*:*</include>
                        </includes>
                    </artifactSet>
            </configuration>
       </execution>
    </executions>
</plugin>

这是实例化 EC2 客户端的代码块片段。

public static void premain(final String agentArgs, Instrumentation instrumentation) {
        log.info("Connecting to AWS...");
        ClientConfiguration clientConfiguration = new ClientConfiguration();
        clientConfiguration.withRetryPolicy(new RetryPolicy(DEFAULT_RETRY_CONDITION,
                                                            new PredefinedBackoffStrategies.ExponentialBackoffStrategy(500, 8000),
                                                            DEFAULT_MAX_ERROR_RETRY,
                                                            true));
        AwsRequests.client = AmazonEC2Client.builder()
                                            .withClientConfiguration(clientConfiguration)
                                            .build();
    }

问题源于 amazonec2client 实际构建时，看起来它仍然希望在 com.amazonaws.services.ec2 包中找到该类，但它已被隐藏到 shaded.com.amazonaws.services.ec2 包。我的理解是，阴影插件会更新底层代码以指向正确的阴影包，我是否遗漏了什么？

感谢任何帮助，谢谢!

Answer 1

我能够解决这个问题，AmazonEC2client init 方法期望以下资源可用:

requestHandler2s.addAll(chainFactory.newRequestHandlerChain("/com/amazonaws/services/ec2/request.handlers"));
requestHandler2s.addAll(chainFactory.newRequestHandler2Chain("/com/amazonaws/services/ec2/request.handler2s"));

我刚刚在我的 pom.xml 上排除了 amazonaws 中转换包下的任何内容，如下所示:

<excludes>
    <exclude>com.amazonaws.services.ec2.model.transform.*</exclude>
</excludes>

它成功了，希望这对将来的人有帮助!