Question

我有一个简单的程序。从头开始，我调用一个URL并将其打开。当我在intellij中运行它时，它可以正常工作，但是命令行不起作用。另外，当我创建另一个Java程序并导入此jar时，也会遇到相同的错误。

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>org.example</groupId>
    <artifactId>XMLConverter</artifactId>
    <version>1.0-SNAPSHOT</version>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>8</source>
                    <target>8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20190722</version>
        </dependency>
    </dependencies>
</project>

缺少依赖项

Exception in thread "main" java.lang.NoClassDefFoundError: org/json/XML
        at xmlconverter.GetXmlData.ReadString(GetXmlData.java:50)
        at xmlconverter.GetXmlData.getJson(GetXmlData.java:24)
        at xmlconverter.XMLConverter.main(XMLConverter.java:13)
Caused by: java.lang.ClassNotFoundException: org.json.XML
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
        ... 3 more

运行此命令时：mvn依赖项：tree我得到了正确的依赖项。

我的假设是因为我有两个.java文件。我有一个主要的，然后是代码。当全部是一个文件XMLConverter时，它运行良好。

Answer 1

https://www.dropwizard.io/en/latest/getting-started.html#building-fat-jars

还将以下插件与您的maven-compiler插件一起添加，以创建jar，在下面的mainclass标记下提及您的主类路径

<plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <version>3.1.0</version>
            <configuration>
                <createDependencyReducedPom>true</createDependencyReducedPom>
                <filters>
                    <filter>
                        <artifact>*:*</artifact>
                        <excludes>
                            <exclude>META-INF/*.SF</exclude>
                            <exclude>META-INF/*.DSA</exclude>
                            <exclude>META-INF/*.RSA</exclude>
                        </excludes>
                    </filter>
                </filters>
            </configuration>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                    <configuration>
                        <transformers>
                            <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
                            <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                <mainClass>com.example. <Path to main class></mainClass>
                            </transformer>
                        </transformers>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins></build>

命令行mvn缺少依赖项

1 个答案: