当使用DNS记录（SRV和TXT）时，无法在Spring上下文中实例化Mongo相关bean

Question

我在没有任何Mongo bean实例化问题的情况下使用了Java8和Spring Data MongoDb Reactive的Javamaven项目。目前，我正在尝试将同一项目从Java8项目升级到Java11（jvm 11.0.8 10-LTS）。我更新的Spring Boot版本是2.5.6，带有Jetty服务器（9.4.44. v20210927），相应的Mongo反应性版本基于2.5.6。当Spring尝试创建与mongo相关的bean以在上下文中添加它们时，会出现以下错误：

Unable to support mongodb+srv// style connections as the ‘com.sun.jndi.dns.DnsContextFactory’ "
+ "class is not available in this JRE. A JNDI context is required for resolving SRV records

除此之外，我尝试了以下方法：

添加设置属性的jndi.properties文件

<代码>java。命名。供应商。url=dns:

将参数添加到maven编译器插件

 <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                        <release>11</release>
                    <compilerArgs>
                        <arg>--add-exports</arg>
                        <arg>jdk.naming.dns/com.sun.jndi.dns=java.naming</arg>
                    </compilerArgs>
                </configuration>
            </plugin>
        </plugins>
    </build>

升级至与java 11兼容的最新jetty server版本

 <jetty.version>9.4.44.v20210927</jetty.version>

<dependency>
  <groupId>org.eclipse.jetty</groupId>
  <artifactId>jetty-webapp</artifactId>
 <version>${jetty.version}</version>
 <scope>provided</scope>
  </dependency>

你能给我一个解决办法吗？

Answer 1

我认为您实际上不必添加--add-export。如果您查看MongoDBJava驱动程序代码，您会看到它已经在添加dns：

这是公关https://github.com/mongodb/mongo-java-driver/pull/554

这可能与JVM有关，但很难证明这一点。您可以使用OpenJDK 11在docker容器上运行它并查看吗？还是不同的版本？

    /*
      It's unfortunate that we take a runtime dependency on com.sun.jndi.dns.DnsContextFactory.
      This is not guaranteed to work on all JVMs but in practice is expected to work on most.
    */
    private static InitialDirContext createDnsDirContext() {
        Hashtable<String, String> envProps = new Hashtable<String, String>();
        envProps.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.dns.DnsContextFactory");
        envProps.put(Context.PROVIDER_URL, "dns:");
        try {
            return new InitialDirContext(envProps);
        } catch (NamingException e) {
            throw new MongoClientException("Unable to support mongodb+srv// style connections as the 'com.sun.jndi.dns.DnsContextFactory' "
                    + "class is not available in this JRE. A JNDI context is required for resolving SRV records.", e);
        }
    }
}

https://github.com/mongodb/mongo-java-driver/blob/master/driver-core/src/main/com/mongodb/internal/dns/DefaultDnsResolver.java