意外错误 404 - 对于在嵌套 springboot jar 中注册的资源

Question

StackOverflow 会员大家好，

我已经完成了到 springboot 3.2.3 和 jetty 12.0.6 的迁移，并且在正确注册 DefaultServlet 的 baseResource 时遇到了问题 - 以前我没有遇到此类问题 - springboot 2.7.X 和较旧的 jetty相同的配置。

我自定义 JettyServletWebServerFactory，添加自己的配置，注册 servlet 等，但有一件事停止工作 - 将 baseResource 定义为嵌套 jar 资源，导致 - 意外错误 - 404，用于将服务启动为 java -jar。

有趣的事实是，它适用于作为 intellij idea 启动器调用服务 - 看起来 baseResource 不作为嵌套资源。

源代码下方：

package com.example.demo;

import jakarta.servlet.ServletRegistration;
import org.eclipse.jetty.ee10.servlet.DefaultServlet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.embedded.jetty.JettyServletWebServerFactory;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;

import java.net.URL;

@SpringBootApplication
public class DemoApplication implements WebServerFactoryCustomizer<JettyServletWebServerFactory> {

    private static final Logger LOGGER = LoggerFactory.getLogger(DemoApplication.class);

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

    @Override
    public void customize(JettyServletWebServerFactory factory) {

        DefaultServlet defaultServlet = new DefaultServlet();
        factory.addInitializers(ctx -> {

            ServletRegistration sr = ctx.addServlet("swagger-ui", defaultServlet);
            sr.addMapping("/swagger-ui/*");

            URL externalForm = DemoApplication.class.getResource("/static/swagger-ui/");

            LOGGER.info("### resources: " + externalForm.toExternalForm());
            sr.setInitParameter("baseResource", externalForm.toExternalForm());
            sr.setInitParameter("pathInfoOnly", "true");

        });
        LOGGER.info("WebServer customized with swagger-ui");

    }
}

pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jersey</artifactId>
            <exclusions>
                <!-- Exclude the Tomcat dependency -->
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
                <exclusion>
                    <artifactId>tomcat-embed-el</artifactId>
                    <groupId>org.apache.tomcat.embed</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <!-- Exclude the Tomcat dependency -->
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jetty</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

回购协议中的完整代码： https://github.com/lmetrak/springboot3-jetty12-compilation

你能看一下并解释一下我做错了什么吗？

Answer 1

Jetty 12 无法访问您的基本目录的 URL。

看起来您正在使用带有内部嵌套文件系统支持的 Spring-Boot 版本，酷！但这意味着您需要禁用别名检查。

这是什么意思？

嗯，类加载器查找生成的 URL 具有嵌套引用。

### resources: jar:nested:/home/joakim/code/jetty/github/springboot3-jetty12-compilation/target/demo-0.0.1-SNAPSHOT.jar/!BOOT-INF/classes/!/static/swagger-ui/

注意到双重嵌套资源了吗？特别是两个

!/

部分？

这会混淆 Jetty 中的内部安全机制，该机制会尝试确定您请求的路径是否是真实路径的别名。

不用担心，您只需禁用别名检查器即可。

这是执行此操作的自定义方法的代码。

import org.eclipse.jetty.ee10.servlet.DefaultServlet;
import org.eclipse.jetty.ee10.servlet.ServletContextHandler;
import org.eclipse.jetty.ee10.servlet.ServletHolder;
import org.springframework.core.io.ClassPathResource;

@Override
public void customize(JettyServletWebServerFactory factory) {
    factory.addInitializers(ctx -> {
        ServletContextHandler servletContextHandler = ServletContextHandler.getServletContextHandler(ctx);
        servletContextHandler.clearAliasChecks();
        servletContextHandler.addAliasCheck((pathInContext, resource)-> true); // disable alias checks by returning true always

        ServletHolder holder = new ServletHolder("swatter-ui", new DefaultServlet());
        servletContextHandler.addServlet(holder, "/swagger-ui/*");

        try {
            URL externalForm = new ClassPathResource("/static/swagger-ui/").getURL();
            LOGGER.info("### resources: " + externalForm.toExternalForm());
            holder.setInitParameter("baseResource", externalForm.toExternalForm());
        } catch (IOException e) {
            throw new RuntimeException("Unable to find /static/swagger-ui");
        }
    });
    LOGGER.info("WebServer customized with swagger-ui");
}