java - 如何修复 "Exception in thread "main"java.lang.NoClassDefFoundError : org/springframework/core/io/support/SpringFactoriesLoader"in Spring Tool Suite

Question

Spring Tool Suite 编辑器在我的代码中没有给出任何错误，但是当我尝试作为 Spring Boot 应用程序运行时，它给了我一个未找到类 def 的异常。我在这里想做的就是运行 Spring Boot 应用程序，它会在控制台中显示 Spring Boot Logo

我已经检查了 xml 文件中的所有依赖项，它们看起来没问题，但并不完全确定。

Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/core/io/support/SpringFactoriesLoader
    at org.springframework.boot.SpringApplication.getSpringFactoriesInstances(SpringApplication.java:428)
    at org.springframework.boot.SpringApplication.getSpringFactoriesInstances(SpringApplication.java:420)
    at org.springframework.boot.SpringApplication.<init>(SpringApplication.java:268)
    at org.springframework.boot.SpringApplication.<init>(SpringApplication.java:249)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248)
    at com.example.ToDoAppApplication.main(ToDoAppApplication.java:10)


Caused by: java.lang.ClassNotFoundException: org.springframework.core.io.support.SpringFactoriesLoader
    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)
    ... 7 more

应该只看到 Spring Boot 应用程序在控制台中成功运行，没有任何错误。

这是我的 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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>ToDoApp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>ToDoApp</name>
    <description>ToDoApp for Spring Boot</description>

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

    <dependencies>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>3.1.3.RELEASE</version><!--$NO-MVN-MAN-VER$-->
    </dependency>

<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-jpa -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>2.1.4.RELEASE</version><!--$NO-MVN-MAN-VER$-->
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.15</version><!--$NO-MVN-MAN-VER$-->
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.security/spring-security-core -->
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-core</artifactId>
        <version>5.1.5.RELEASE</version><!--$NO-MVN-MAN-VER$-->
    </dependency>

<!-- https://mvnrepository.com/artifact/org.springframework.security/spring-security-web -->
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-web</artifactId>
        <version>5.1.5.RELEASE</version><!--$NO-MVN-MAN-VER$-->
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.security/org.springframework.security.config -->
<!--    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>org.springframework.security.config</artifactId>
        <version>3.1.3.RELEASE</version>
    </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>

Answer 1

你的依赖关系一团糟。您正在混合不兼容的版本，因此会出现错误。清理 pom.xml 中的依赖项.

<dependencies>

    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-jpa -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

删除spring-core依赖关系，这可能是罪魁祸首。不要使用<version />包含起始符时的标签，这些标签是通过父级管理的。使用 spring-boot-starter-security 而不是单独的 Spring Security 依赖项反而。您还有重复的mysql-connector-java依赖关系。