Spring 微服務：servlet [jsp] 的 Servlet.service() 拋出異常

Question

我使用 Spring 微服務並收到以下錯誤，

2020-01-20 09:58:22.504 ERROR 13758 --- [nio-8080-exec-1] o.a.c.c.C.[.[localhost].[/].[jsp]        : Servlet.service() for servlet [jsp] threw exception

java.lang.ClassNotFoundException: org.apache.tomcat.util.security.Escape
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[na:1.8.0_211]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_211]
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) ~[na:1.8.0_211]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_211]
    at org.apache.jasper.compiler.JspUtil.getExprInXml(JspUtil.java:85) ~[tomcat-embed-jasper-9.0.29.jar:9.0.29]
    at org.apache.jasper.compiler.PageDataImpl$SecondPassVisitor.printAttributes(PageDataImpl.java:736) ~[tomcat-embed-jasper-9.0.29.jar:9.0.29]

在瀏覽器中，它提供了錯誤，

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Mon Jan 20 09:58:22 BDT 2020
There was an unexpected error (type=Internal Server Error, status=500).
org/apache/tomcat/util/security/Escape

我提供了來自相應微服務的一些代碼片段，

@SpringBootApplication
@EnableCircuitBreaker
@EnableDiscoveryClient
@EnableFeignClients

public class Application {

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

    @Bean
    public RestTemplate restTemplate(RestTemplateBuilder builder) {
        return builder.build();
    }
}

控制器類，

@Controller
@Transactional
@RequestMapping("/website/vehicles")
public class VehicleController {


    @Autowired
    private VehicleRepository data;

    @Autowired
    private PositionTrackingExternalService externalService;

    @PostMapping(value = "/newVehicle.html")
    public String newVehicle(Vehicle vehicle) {

        data.save(vehicle);
        return "redirect:/website/vehicles/list.html";
    }

    @PostMapping(value = "/deleteVehicle.html")
    public String deleteVehicle(@RequestParam Long id) {

        data.delete(id);
        return "redirect:/website/vehicles/list.html";
    }

    @GetMapping(value = "/newVehicle.html")
    public ModelAndView renderNewVehicleForm() {

        Vehicle newVehicle = new Vehicle();
        return new ModelAndView("newVehicle", "form", newVehicle);
    }

    @GetMapping(value = "/list.html")
    public ModelAndView vehicles() {

        List<Vehicle> allVehicles = data.findAll();
        return new ModelAndView("allVehicles", "vehicles", allVehicles);
    }


    ......  .....   ......  .....  ......  .....
    ......  .....   ......  .....  ......  .....

}

假客戶，

@FeignClient(name = "fleetman-position-tracker")
public interface RemotePositionMicroserviceCalls {

    @GetMapping(value = "/vehicles/{name}")
    public Position getLatestPositionForVehicle(@PathVariable(value = "name") String name);
}

服務類，

@Service
public class PositionTrackingExternalService {


    @Autowired
    private ObjectProvider<RemotePositionMicroserviceCalls> remoteService;

    @Autowired
    private VehicleRepository repository;

    @HystrixCommand(fallbackMethod = "handleExternalServiceDown")
    public Position getLatestPositionForVehicleFromRemoteMicroservice(String name) {

        Position response = remoteService.getObject().getLatestPositionForVehicle(name);

        response.setUpToDate(true);
        return response;
    }

    public Position handleExternalServiceDown(String name) {

        // Read the last known position for this vehicle
        Position position = new Position();
        Vehicle vehicle = repository.findByName(name);

        position.setLat(vehicle.getLat());
        position.setLongitude(vehicle.getLongitude());
        position.setTimestamp(vehicle.getLastRecordedPosition());
        position.setUpToDate(false);

        return position;
    }

}

項目結構，

根據要求，下面提供了pom.xml文件，

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.transport.visualizer</groupId>
    <artifactId>transport-visualizer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>TransportVisualizer</name>
    <description>Vehicle Transport Visualizer</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.3.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
        </dependency>

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

        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>    

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
        </dependency>       

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
        </dependency>           

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
        </dependency>   

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency> 
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Camden.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

        <resources>
            <resource>
                <filtering>true</filtering>
                <directory>src/main/resources</directory>
                <includes>
                    <include>application.properties</include>
                </includes>
            </resource>     
        </resources>

    </build>        
</project>

這里有什么問題，我該如何解決？

Answer 1

將您的 jasper 依賴項更改為

<dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <scope>provided</scope>
</dependency>

Answer 2

依賴項應該配置為提供的范圍：

<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-jasper</artifactId>
    <scope>provided</scope>
</dependency>