java - 创建新的 ClassPathXmlApplicationContext 时出现 ClassNotFoundException

Question

这个问题已经有答案了:

What causes and what are the differences between NoClassDefFoundError and ClassNotFoundException? (15 个回答)

已关闭 7 年前。

我正在调用this Spring bean 范围教程。我手动设置了所有内容，然后使用 Maven 进行打包。这是我的项目结构:

.
├── pom.xml
├── src
│   └── main
│       ├── java
│       │   └── hello
│       │       ├── HelloWorld.java
│       │       └── MainApp.java
│       └── resources
│           └── Beans.xml

HelloWorld.java:

package hello;

public class HelloWorld {

    private String message;

    public void setMessage(String message) {
        this.message = message;
    }

    public String getMessage() {
        return message;
    }
}

MainApp.java:

package hello;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {

    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");

        HelloWorld objA = (HelloWorld) context.getBean("helloWorld");

        objA.setMessage("I'm object A");
        System.out.println("Your Message: " + objA.getMessage());

        HelloWorld objB = (HelloWorld) context.getBean("helloWorld");
        System.out.println("Your Message: " + objB.getMessage());
    }
}

Beans.xml:

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="helloWorld" class="hello.HelloWorld" scope="singleton">
    </bean>

</beans>

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

    <groupId>hello</groupId>
    <artifactId>hello</artifactId>
    <version>0.0.1</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.3.0.RELEASE</version>
    </parent>

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

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
        </dependency>
    </dependencies>

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

</project>

然后我像这样运行 jar:

java -jar target/hello-0.0.1.jar 

并获取此日志:

java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:53)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
    at org.springframework.context.support.AbstractApplicationContext.<init>(AbstractApplicationContext.java:158)
    at org.springframework.context.support.AbstractApplicationContext.<init>(AbstractApplicationContext.java:222)
    at org.springframework.context.support.AbstractRefreshableApplicationContext.<init>(AbstractRefreshableApplicationContext.java:88)
    at org.springframework.context.support.AbstractRefreshableConfigApplicationContext.<init>(AbstractRefreshableConfigApplicationContext.java:58)
    at org.springframework.context.support.AbstractXmlApplicationContext.<init>(AbstractXmlApplicationContext.java:61)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:136)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
    at hello.MainApp.main(MainApp.java:9)
    ... 6 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at org.springframework.boot.loader.LaunchedURLClassLoader.doLoadClass(LaunchedURLClassLoader.java:166)
    at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:130)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 14 more

你能告诉我，我做错了什么吗？

Answer 1

您有ClassNotFoundException:org.apache.commons.logging.LogFactory。
将此依赖项添加到文件 pom.xml 以修复错误。

<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.1.1</version>
</dependency>