java - 在 Spring 中继续获取 java.lang.NoClassDefFoundError

Question

我真的不知道我的Spring配置有什么问题。你能 Handlebars 给我吗？

我的代码(简化版):

应用程序.java:

public class App {
public static void main(String[] args) {
    AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);
    ctx.close();
}

配置.java:

@Configuration
@ComponentScan
public class Config {
    @Bean
    public JdbcOperations jdbcTemplate(DataSource ds) {
        return new JdbcTemplate(ds);
    }
}

pom文件:

 <properties>

    <!-- Generic properties -->
    <java.version>1.6</java.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

    <!-- Spring -->
    <spring-framework.version>4.2.5.RELEASE</spring-framework.version>

    <!-- Hibernate / JPA -->
    <hibernate.version>4.2.1.Final</hibernate.version>

    <!-- Logging -->
    <logback.version>1.0.13</logback.version>
    <slf4j.version>1.7.5</slf4j.version>

    <!-- Test -->
    <junit.version>4.11</junit.version>

</properties>

<dependencies>
    <!-- Spring and Transactions -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${spring-framework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>${spring-framework.version}</version>
    </dependency>

    <!-- Logging with SLF4J & LogBack -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>${slf4j.version}</version>
        <scope>compile</scope>
    </dependency>
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>${logback.version}</version>
        <scope>runtime</scope>
    </dependency>

    <!-- Hibernate -->
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>${hibernate.version}</version>
    </dependency>


    <!-- Test Artifacts -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>${spring-framework.version}</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>${junit.version}</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.2.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <version>1.4.185</version>
    </dependency>
</dependencies>
<build>
    <plugins>
        <plugin>
            <!-- Build an executable JAR -->
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.4</version>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>App</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>

我的文件夹结构:

在我用 maven 打包之后，当我运行我得到的 jar 时:

    Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/context/annotation/AnnotationConfigApplicationContext
        at App.main(App.java:10)
Caused by: java.lang.ClassNotFoundException: org.springframework.context.annotation.AnnotationConfigApplicationContext
        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)

其中，第10行是AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);

另外: 我在观看 Spring 教程时正在编写代码:Spring Framework Tutorial 4: Database programming with JdbcTemplate

他的源代码位于:github 与源代码的唯一区别是我在 pom 文件中添加了 MainClass。

非常感谢!
此致

Answer 1

这样做的原因是，在您的 jar 中，您只有您的类，没有任何依赖项。要在 jar 中包含所有依赖项，您需要创建一个 fat jar。

在 pom.xml 中用以下内容替换您的构建 block :

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.4.1</version>
                <configuration>
                    <!-- get all project dependencies -->
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                    <!-- MainClass in mainfest make a executable jar -->
                    <archive>
                        <manifest>
                            <mainClass>App</mainClass>
                        </manifest>
                    </archive>

                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <!-- bind to the packaging phase -->
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

运行 mvn clean package 后，您将在目标目录中获得两个 jar，第一个没有依赖关系，第二个有依赖关系。运行第二个 jar。

1. CustomerJdbc-0.0.1-SNAPSHOT.jar
2. CustomerJdbc-0.0.1-SNAPSHOT-jar-with-dependencies.jar