java - EAR 类加载器看不到位于 jar 中的 ApplicationInsights.xml

Question

我有以下问题:我尝试在 jar 文件中部署 Azure 遥测配置，该文件位于 main ear 内的 war 文件中。不幸的是，在服务器启动期间，由于找不到 ApplicationInsights.xml，会发生一些错误。我对其进行了调试，发现 com.microsoft.applicationinsights.internal.config.ConfigurationFileLocator.getConfigurationFile() 无法读取它。

我的模块有一个结构:

azure
|_ src
   |_ main
         |_ java
         |     |_ mypackage
         |                |_ MicrometerRegistryConfigurationListener.java
         |_ resources
                    |_ ApplicationInsights.xml

有MicrometerRegistryConfigurationListener.java:

@WebListener
public class MicrometerRegistryConfigurationListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        MeterRegistry azureMeterRegistry = new AzureMonitorMeterRegistry(new AzureMonitorConfig() {
            @Override
            public String get(String key) {
                return null;
            }

            @Override
            public Duration step() {
                return Duration.ofSeconds(5);
            }
        }, Clock.SYSTEM);

        new JvmThreadMetrics().bindTo(azureMeterRegistry);
        new JvmMemoryMetrics().bindTo(azureMeterRegistry);
        new JvmGcMetrics().bindTo(azureMeterRegistry);

        servletContextEvent.getServletContext().setAttribute("AzureMonitorMeterRegistry", azureMeterRegistry);
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {

    }
}

并且有一个ear的结构:

ear
  |_ war
       |_ WEB-INF/lib
                    |_ azure.jar
                               |_ ApplicationInsights.xml

当然，azure.jar 也包含类，i.a. MicrometerRegistryConfigurationListener。

到底是怎么回事？为什么 ApplicationInsights.xml 不可见？

Answer 1

因为 jar 是一个文件，它不是一个文件夹。加载器尝试访问文件系统路径，但它无法访问 JAR 中的路径。所以你可以使用 resource.getInputStream()方法将其作为 InputStream 检索。您可以从该文档中获取详细信息:Java: Load file from classpath in Spring Boot .

示例代码:

public class EnvResolver {
private ResourceLoader resourceLoader;
public EnvResolver(){
    resourceLoader = new DefaultResourceLoader();
}
public List GetEnvConfig() throws IOException {
    Yaml yaml = new Yaml();
    Resource resource = resourceLoader.getResource("classpath:test-environment.yml");
    System.out.println("FileName: " + resource.getFilename());
    InputStream inputStream = resource.getInputStream();
    Map<String, Map<String, String>> result = yaml.load(inputStream);
    List<TestEnvVo> envList = new ArrayList<>();
    for (String key : result.keySet()) {
        TestEnvVo testEnvVo = new TestEnvVo();
        testEnvVo.setEnvName(result.get(key).get("name"));
        testEnvVo.setDomain(result.get(key).get("domain"));
        envList.add(testEnvVo);
    }
    inputStream.close();
    return envList;
}
}

经过搜索，我找到了另一种配置方法，在您的 POM 文件中添加 resources配置。你可以试一试。

<resources>
    <resource>
        <directory>src/main/resource</directory>
        <includes>
            <include>**/*.properties</include>
            <include>**/*.xml</include>
            <include>**/*.tld</include>
        </includes>
        <filtering>false</filtering>
    </resource>
</resources>

希望这可以帮助你。

更新:

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;

public class Hello {

    public static void main(String[] args) throws IOException {
        InputStream resourceInputStream = null;
        URL resourceURL = Hello.class.getClassLoader().getResource("resources/hello.json");
        if(resourceURL == null) {
            System.out.println("Get the InputStream of file in IDE");
            resourceInputStream = new FileInputStream(Hello.class.getClassLoader().getResource("").getPath()+"../../src/main/resources/hello.json");
        } else {
            System.out.println("Get the InputStream of file from runnable jar");
            resourceInputStream = Hello.class.getClassLoader().getResourceAsStream("resources/hello.json");
        }
        System.out.println();
        StringBuilder builder = new StringBuilder();
        BufferedReader br = new BufferedReader(new InputStreamReader(resourceInputStream));
        String line = null;
        while((line = br.readLine()) != null) {
            builder.append(line+"\n");
        }
        br.close();
        System.out.println(builder.toString());
    }
    }