在目标文件夹中运行 jar 与在项目文件夹中运行 jar

Question

我有奇怪的问题。 当我从项目文件夹运行 jar 时：

java -jar ./target/project.jar

一切正常，路径读取正确。

1107 [main] INFO org.apache.camel.core.xml.AbstractCamelContextFactoryBean - JMXAgent enabled: CamelJMXAgent[usePlatformMBeanServer=true, createConnector=true, registryPort=10098, serviceUrlPath=/, statisticsLevel=All, onlyRegisterProcessorWithCustomId=false, registerAlways=true, registerNewRoutes=true, mask=false]
2657 [main] INFO org.apache.camel.impl.converter.DefaultTypeConverter - Loaded 179 type converters
2853 [main] INFO org.apache.camel.spring.SpringCamelContext - Apache Camel 2.12.2 (CamelContext: data-feed-camel) is starting
2853 [main] INFO org.apache.camel.management.ManagedManagementStrategy - JMX is enabled
3078 [Camel Thread #1 - Camel Thread #0 - JMXConnector: service:jmx:rmi:///jndi/rmi://pjanik-pc:10098/] INFO org.apache.camel.management.DefaultManagementAgent - JMX Connector thread started and listening at: service:jmx:rmi:///jndi/rmi://pjanik-pc:10098/f

3089 [main] INFO org.apache.camel.spring.SpringCamelContext - StreamCaching is not in use. If using streams then its recommended to enable stream caching. See more details at http://camel.apache.org/stream-caching.html
3107 [main] INFO org.apache.camel.spring.SpringCamelContext - Total 0 routes, of which 0 is started.
3128 [main] INFO org.apache.camel.spring.SpringCamelContext - Apache Camel 2.12.2 (CamelContext: data-feed-camel) started in 0.255 seconds


org.apache.camel.component.file.FileEndpoint - Endpoint is configured with noop=true so forcing endpoint to be idempotent as well
    59471 [RMI TCP Connection(5)-10.88.55.167] INFO org.apache.camel.spring.SpringCamelContext - Route: flt_data_for_0543 started and consuming from: Endpoint[file://src/main/resources/view/flight/following/default/3648/flt_data?idempotentRepository=%23repo-flt_data_for_0543&noop=true&readLock=none]
    60552 [Camel (data-feed-camel) thread #4 -

但是当我在目标文件夹中运行 jar 时

1149 [main] INFO org.apache.camel.core.xml.AbstractCamelContextFactoryBean - JMXAgent enabled: CamelJMXAgent[usePlatformMBeanServer=true, createConnector=true, registryPort=10098, serviceUrlPath=/, statisticsLevel=All, onlyRegisterProcessorWithCustomId=false, registerAlways=true, registerNewRoutes=true, mask=false]
2688 [main] INFO org.apache.camel.impl.converter.DefaultTypeConverter - Loaded 179 type converters
2796 [main] INFO org.apache.camel.spring.SpringCamelContext - Apache Camel 2.12.2 (CamelContext: data-feed-camel) is starting
2796 [main] INFO org.apache.camel.management.ManagedManagementStrategy - JMX is enabled
2975 [Camel Thread #1 - Camel Thread #0 - JMXConnector: service:jmx:rmi:///jndi/rmi://pjanik-pc:10098/] INFO org.apache.camel.management.DefaultManagementAgent - JMX Connector thread started and listening at: service:jmx:rmi:///jndi/rmi://pjanik-pc:10098/
2981 [main] INFO org.apache.camel.spring.SpringCamelContext - StreamCaching is not in use. If using streams then its recommended to enable stream caching. See more details at http://camel.apache.org/stream-caching.html
2989 [main] INFO org.apache.camel.spring.SpringCamelContext - Total 0 routes, of which 0 is started.
2991 [main] INFO org.apache.camel.spring.SpringCamelContext - Apache Camel 2.12.2 (CamelContext: data-feed-camel) started in 0.194 seconds
21055 [RMI TCP Connection(4)-10.88.55.167] INFO org.apache.camel.component.file.FileEndpoint - Endpoint is configured with noop=true so forcing endpoint to be idempotent as well
21588 [RMI TCP Connection(4)-10.88.55.167] INFO org.apache.camel.spring.SpringCamelContext - Route: flt_data_for_0432 started and consuming from: Endpoint[file://src/main/resources/view/flight/following/default/3648/flt_data?idempotentRepository=%23repo-flt_data_for_0432&noop=true&readLock=none]

它卡住了，没有进一步做

路径始终相同：

private static final String DEFAULT_DATA_PATH = "view/flight/following/default/3648/";

有什么问题？ 我怎样才能避免这种情况？

Answer 1

您的 Camel 路由从端点file://src/main/resources/view/flight/following/default/3648/flt_data ，它作为相对路径给出（我猜在您的项目中）。 因此，当您从target目录执行 jar 时，它会有所不同。 这是因为您是直接从文件系统而不是从类路径中读取文件。

为了避免这种情况，有（至少）两种方法：

1. 您将文件视为应用程序使用的提供的数据：然后将文件的路径作为应用程序的参数传递并将其传递给您的路由，您当前使用的文件名常量可能变得无用。

2. 您将文件视为资源（即某种不可变数据）：然后您可以为您的资源创建一个InputStream并从中读取字节。 在你的情况下，你会写这样的东西：

    InputStream resourceStream = getClass().getResourceAsStream(DEFAULT_FLT_DATA_PATH); // Read bytes from resourceStream

有关getResourceAsStream的文档，请参见此处。

如果您必须使用 Camel 路由，则此答案建议您可以使用 Camel 的Stream 组件（它还建议使用InputStream的上述方法，但细节较少）。 但是，它没有提到如何，我也不知道。 我建议要求对该答案进行澄清。