java.lang.NoClassDefFoundError :org/springframework/web/util/UriTemplateHandler

Question

我有一个使用 Spring Initializer 创建的基本 SpringBoot 应用程序。当我尝试启动 SpringBoot 服务器(使用 maven 插件 (spring-boot:start) 时，出现以下错误。

java.lang.NoClassDefFoundError: org/springframework/web/util/UriTemplateHandler at java.lang.Class.getDeclaredConstructors0(Native Method) ~[na:1.8.0_60] at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671) ~[na:1.8.0_60] at java.lang.Class.getDeclaredConstructors(Class.java:2020) ~[na:1.8.0_60] at org.springframework.boot.context.properties.ConfigurationPropertiesBindConstructorProvider.findConstructorBindingAnnotatedConstructor(ConfigurationPropertiesBindConstructorProvider.java:62) ~[spring-boot-2.2.4.RELEASE.jar:2.2.4.RELEASE] at org.springframework.boot.context.properties.ConfigurationPropertiesBindConstructorProvider.getBindConstructor(ConfigurationPropertiesBindConstructorProvider.java:48) ~[spring-boot-2.2.4.RELEASE.jar:2.2.4.RELEASE] at org.springframework.boot.context.properties.ConfigurationPropertiesBean$BindMethod.forType(ConfigurationPropertiesBean.java:311) ~[spring-boot-2.2.4.RELEASE.jar:2.2.4.RELEASE] at org.springframework.boot.context.properties.ConfigurationPropertiesBeanDefinitionValidator.validate(ConfigurationPropertiesBeanDefinitionValidator.java:63) ~[spring-boot-2.2.4.RELEASE.jar:2.2.4.RELEASE] at org.springframework.boot.context.properties.ConfigurationPropertiesBeanDefinitionValidator.postProcessBeanFactory(ConfigurationPropertiesBeanDefinitionValidator.java:45) ~[spring-boot-2.2.4.RELEASE.jar:2.2.4.RELEASE] at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:286) ~[spring-context-5.2.3.RELEASE.jar:5.2.3.RELEASE] at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:174) ~[spring-context-5.2.3.RELEASE.jar:5.2.3.RELEASE]

这是我的 pom 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 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>2.2.4.RELEASE</version>
        <relativePath/>
    </parent>
    <groupId>com.cgtm</groupId>
    <artifactId>validator</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>validator</name>
    <description>Validator</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

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

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.1.6.RELEASE</version>
        </dependency>


        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.2</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

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

</project>

Application.java 文件

 package com.cgtm.validator;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class ValidatorApplication {

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

}

Answer 1

Spring boot 的版本为 2.2.4，它需要 Spring 5(基本上它带有预定义版本的 spring

另一方面，您使用的是“硬编码”的 spring web 4.1.4，这是错误的:

 <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>4.1.6.RELEASE</version>
 </dependency>

你应该使用:

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

确保您的路径上没有任何 spring 4.x 依赖项(通过运行 mvn dependency:tree)

此外，您不需要放置:

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

最后一件事，你使用的是 lombok，这当然没问题(我的意思是 spring 可以很好地与 lombok 配合使用)，但是 spring boot maven 插件仍然会将其打包到工件中，尽管提供了 范围。如果您希望将其从最终工件中排除，则必须配置 Spring Boot Maven 插件本身才能执行此操作。

阅读this SO thread了解更多信息