NoClassDefFoundError的com/快速xml/杰克逊/数据库/ObjectMapper与Maven

Question

这是一个与这里的问题类似的问题，不幸的是，这个问题尚未解决。

如果您想调试代码，下面是GitHub repo。

虽然我已将相关依赖项添加到Mavepom，但我为ObjectMapper获得了以下NoClassDefFoundError。xml。

Exception in thread "main" java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/ObjectMapper
    at demo.DemoMain.main(DemoMain.java:10)
Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.databind.ObjectMapper
    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)
    ... 1 more

下面是源代码演示。java

package demo;

import com.fasterxml.jackson.databind.ObjectMapper;

public class DemoMain {
    public static void main(String[] args) {
        System.out.println("Start");
        ObjectMapper mapper = new ObjectMapper();
        System.out.println("End");
    }
}

这是我的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>com.example</groupId>
<artifactId>Demo</artifactId>
<version>1.0-SNAPSHOT</version>

<dependencies>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.8.3</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.8.3</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.8.3</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>3.0.0</version>
            <configuration>
                <archive>
                    <index>true</index>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <mainClass>demo.DemoMain</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>

我编译并运行应用程序

mvn clean install
java -jar target/Demo-1.0-SNAPSHOT.jar

Answer 1

<dependency>
<groupId>com.fasterxml.jackson.dataformat</groupId>
<artifactId>jackson-dataformat-xml</artifactId>
<version>2.8.5</version>
</dependency>

Answer 2

正如我在这里回答的

默认的maven插件不会构建具有依赖项的胖jar。

为了构建一个与依赖项捆绑在一起的jar，以便我们可以使用java-jar执行它，我们可以使用maven assembly插件，该插件将jar打包为具有依赖项的名称xxx jar。jar。

这是一个pom示例。xml

<build>
    <plugins>
        <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>3.0.0</version>
            <configuration>
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
                <archive>
                    <manifest>
                        <mainClass>com.example.yourMain</mainClass>
                    </manifest>
                </archive>
            </configuration>
            <executions>
                <execution>
                    <id>make-assembly</id> <!-- this is used for inheritance merges -->
                    <phase>package</phase> <!-- bind to the packaging phase -->
                    <goals>
                        <goal>single</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

现在你应该可以用它来运行你的罐子了

java -jar xxx-jar-with-dependencies.jar