java - Swagger with Jersey 2 抛出 java.lang.NoClassDefFoundError : javax/servlet/ServletConfig

Question

尝试设置我的第一个 REST API(使用 Jersey 2 和 Gradle)并使用 swagger 添加一些文档。但是当添加 swagger 依赖项并遵循 this 时swagger 文档，“Using a custom Application subclass”方法，当从 Eclipse 执行主要方法时，它抛出这个异常:

Exception in thread "main" java.lang.NoClassDefFoundError: javax/servlet/ServletConfig
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.getDeclaredMethods(Class.java:1975)
    at org.glassfish.jersey.server.model.IntrospectionModeller$2.run(IntrospectionModeller.java:253)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.glassfish.jersey.server.model.IntrospectionModeller.getAllDeclaredMethods(IntrospectionModeller.java:247)
    at org.glassfish.jersey.server.model.IntrospectionModeller.checkForNonPublicMethodIssues(IntrospectionModeller.java:172)
    at org.glassfish.jersey.server.model.IntrospectionModeller.doCreateResourceBuilder(IntrospectionModeller.java:119)
    at org.glassfish.jersey.server.model.IntrospectionModeller.access$000(IntrospectionModeller.java:80)
    at org.glassfish.jersey.server.model.IntrospectionModeller$1.call(IntrospectionModeller.java:112)
    at org.glassfish.jersey.server.model.IntrospectionModeller$1.call(IntrospectionModeller.java:109)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.processWithException(Errors.java:255)
    at org.glassfish.jersey.server.model.IntrospectionModeller.createResourceBuilder(IntrospectionModeller.java:109)
    at org.glassfish.jersey.server.model.Resource.from(Resource.java:797)
    at org.glassfish.jersey.server.ApplicationHandler.initialize(ApplicationHandler.java:465)
    at org.glassfish.jersey.server.ApplicationHandler.access$500(ApplicationHandler.java:184)
    at org.glassfish.jersey.server.ApplicationHandler$3.call(ApplicationHandler.java:350)
    at org.glassfish.jersey.server.ApplicationHandler$3.call(ApplicationHandler.java:347)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.processWithException(Errors.java:255)
    at org.glassfish.jersey.server.ApplicationHandler.<init>(ApplicationHandler.java:347)
    at org.glassfish.jersey.server.ApplicationHandler.<init>(ApplicationHandler.java:299)
    at org.glassfish.jersey.jdkhttp.JdkHttpHandlerContainer.<init>(JdkHttpHandlerContainer.java:98)
    at org.glassfish.jersey.jdkhttp.JdkHttpServerFactory.createHttpServer(JdkHttpServerFactory.java:111)
    at org.glassfish.jersey.jdkhttp.JdkHttpServerFactory.createHttpServer(JdkHttpServerFactory.java:93)
    at example.MyApp.main(MyApp.java:21)
Caused by: java.lang.ClassNotFoundException: javax.servlet.ServletConfig
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 29 more

我的代码是这样的:

package example;
import static org.glassfish.jersey.jdkhttp.JdkHttpServerFactory.createHttpServer;
import java.net.URI;
import javax.ws.rs.core.UriBuilder;
import org.glassfish.jersey.jackson.JacksonFeature;
import org.glassfish.jersey.server.ResourceConfig;
import com.sun.net.httpserver.HttpServer;
import io.swagger.jaxrs.listing.ApiListingResource;
import io.swagger.jaxrs.listing.SwaggerSerializers;

public class MyApp extends ResourceConfig {

    public static void main(String[] args) throws Throwable {
        URI baseUri = UriBuilder.fromUri("http://localhost/").port(9999).build();
        HttpServer server = createHttpServer(baseUri, new MyApp());
        System.out.println("SERVICE started at: " + baseUri);
        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            server.stop(0);
        }));
    }

    public MyApp() {
        packages("example");
        register(SwaggerSerializers.class); // <-- swagger specific
        register(ApiListingResource.class); // <-- swagger specific
        register(JacksonFeature.class);
    }
}

我的gradle依赖

dependencies {
    compile 'com.fasterxml.jackson.jaxrs:jackson-jaxrs-json-provider:+'
    compile 'org.glassfish.jersey.containers:jersey-container-jdk-http:+'
    compile 'org.glassfish.jersey.media:jersey-media-moxy:+'
    compile 'org.glassfish.jersey.media:jersey-media-json-jackson:+'
    compile 'io.swagger:swagger-jersey2-jaxrs:1.5.9'
}

在 Windows 7 上使用 jdk1.8.0_77

但是，如果我在代码中注释掉 swagger 依赖项和 swagger 细节，那么实际的 REST 服务将按预期工作。如何在不使用 servlet 容器的情况下使 swagger 工作？ REST 服务可以在没有它的情况下工作

dependencies {
    compile 'com.fasterxml.jackson.jaxrs:jackson-jaxrs-json-provider:+'
    compile 'org.glassfish.jersey.containers:jersey-container-jdk-http:+'
    compile 'org.glassfish.jersey.media:jersey-media-moxy:+'
    compile 'org.glassfish.jersey.media:jersey-media-json-jackson:+'
//    compile 'io.swagger:swagger-jersey2-jaxrs:1.5.9'
}

代码:

package example;
import static org.glassfish.jersey.jdkhttp.JdkHttpServerFactory.createHttpServer;
import java.net.URI;
import javax.ws.rs.core.UriBuilder;
import org.glassfish.jersey.jackson.JacksonFeature;
import org.glassfish.jersey.server.ResourceConfig;
import com.sun.net.httpserver.HttpServer;
import io.swagger.jaxrs.listing.ApiListingResource;
import io.swagger.jaxrs.listing.SwaggerSerializers;

public class MyApp extends ResourceConfig {

    public static void main(String[] args) throws Throwable {
        URI baseUri = UriBuilder.fromUri("http://localhost/").port(9999).build();
        HttpServer server = createHttpServer(baseUri, new MyApp());
        System.out.println("SERVICE started at: " + baseUri);
        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            server.stop(0);
        }));
    }

    public MyApp() {
        packages("example");
        // register(SwaggerSerializers.class); // <-- swagger specific
        // register(ApiListingResource.class); // <-- swagger specific
        register(JacksonFeature.class);
    }
}

Answer 1

所以看起来问题是由您在非 servlet 环境中运行引起的。虽然 Jersey 支持它，但 swagger-core ......不是那么多。这给特定部署带来了一些问题，尽管它们不太常见。

显然，最简单的解决方案是使用 servlet 容器引擎。像 Jetty 这样的轻量级的东西可以工作。