Java 就术语进行争论。下面的答案大致概括了这一点。要么将所有依赖项都包含到jar中（uber jar或可执行jar），要么在命令行上用-cp指定整个类路径。Maven只在构建过程中解决依赖关系，而不是在终端上运行时。我尝试了您的选项#1（#2不是一个长话短说的选

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就术语进行争论。下面的答案大致概括了这一点。要么将所有依赖项都包含到jar中（uber jar或可执行jar），要么在命令行上用

-cp

指定整个类路径。Maven只在构建过程中解决依赖关系，而不是在终端上运行时。我尝试了您的选项#1（#2不是一个长话短说的选项，现在要避免#3，直到我从根本上理解它是如何工作的）。。。无论如何，我将导入的依赖项像这样放在类路径上，但仍然失败。思想？java-cp/opt/workspace/eclipse/java/quickstart/target/quickstart-0.0.1-SNAPSHOT.jar com.dogzilla.maven.quickstart.App:com.google.code.gson上面包含的命令行看起来不像是正确的方法。听起来你对Java还不熟悉；我建议多读点书（或者使用#2或#3，让Maven帮你解决问题）。与其侮辱你，不如试着帮助你。在op中，我演示了我知道如何使用-cp。如果我使用System.out.println而不是System.out.println（gson.toJson，它与这个命令java-cp/opt/workspace/eclipse/java/quickstart/target/quickstart-0.0.1-SNAPSHOT.jar-com.dogzilla.maven.quickstart.App一起工作。我也“阅读”（感谢阅读BTW的提示；非常有用）为了在类路径中使用多个路径，冒号被用作删除器。我试图提供帮助；很抱歉您没有这样解释它。我不感谢您上次的回答；我在这里完成了。祝您解决问题好运。我尝试了您的选项#1（#2不是一个长话短说的选项，除非我从根本上理解它是如何工作的，否则现在就避免使用#3）…无论如何，我像这样将导入的依赖项放在类路径上，但仍然失败了。想法？java-cp/opt/workspace/eclipse/java/quickstart/target/quickstart-0.0.1-SNAPSHOT.jar.com.dogzilla.maven.quickstart.App:com.google.code.gson上面包含的命令行看起来不像是正确的方法#1。听起来你是新手Java；我建议多读一些书（或者使用#2或#3，让Maven帮你解决问题）。与其说是侮辱，不如说是帮助。在op中，我演示了我知道如何使用-cp。如果我使用System.out.println而不是System.out.println（gson.toJson，它与这个命令java-cp/opt/workspace/eclipse/java/quickstart/target/quickstart-0.0.1-SNAPSHOT.jar com.dogzilla.maven.quickstart.App一起工作。我也“读过”（感谢阅读提示；非常有用）为了在类路径中使用多个路径，冒号被用作除名符。我试图提供帮助；很抱歉您没有这样解释它。我不感谢您上次的回答；我在这里完成了。祝您好运解决您的问题。

1.  File -> New -> Other... Maven -> Maven Project
2.  Used the maven-archetype-quickstart archetype

    Group ID:  com.dogzilla.maven
    Artifact ID:  quickstart

Group ID: com.google.code.gson
Artifact ID: gson
Version: 2.8.6

<?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.dogzilla.maven</groupId>
  <artifactId>quickstart</artifactId>
  <version>0.0.1-SNAPSHOT</version>

  <name>quickstart</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.8.6</version>
    </dependency>
  </dependencies>

  <build>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>3.7.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-project-info-reports-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

package com.dogzilla.maven.quickstart;

import com.google.gson.Gson;

public class App 
{
    public static void main( String[] args )
    {
        Gson gson = new Gson();
        System.out.println(gson.toJson("Hello World!") );
    }
}

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/opt/eclipse/java/plugins/org.eclipse.m2e.maven.runtime.slf4j.simple_1.16.0.20200610-1735/jars/slf4j-simple-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [file:/opt/eclipse/java/configuration/org.eclipse.osgi/5/0/.cp/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.SimpleLoggerFactory]
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/opt/eclipse/java/plugins/org.eclipse.m2e.maven.runtime.slf4j.simple_1.16.0.20200610-1735/jars/slf4j-simple-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [file:/opt/eclipse/java/configuration/org.eclipse.osgi/5/0/.cp/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.SimpleLoggerFactory]
[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------< com.dogzilla.maven:quickstart >--------------------
[INFO] Building quickstart 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:3.1.0:clean (default-clean) @ quickstart ---
[INFO] Deleting /opt/workspace/eclipse/java/quickstart/target
[INFO] 
[INFO] --- maven-resources-plugin:3.0.2:resources (default-resources) @ quickstart ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /opt/workspace/eclipse/java/quickstart/src/main/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ quickstart ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /opt/workspace/eclipse/java/quickstart/target/classes
[INFO] 
[INFO] --- maven-resources-plugin:3.0.2:testResources (default-testResources) @ quickstart ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /opt/workspace/eclipse/java/quickstart/src/test/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ quickstart ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /opt/workspace/eclipse/java/quickstart/target/test-classes
[INFO] 
[INFO] --- maven-surefire-plugin:2.22.1:test (default-test) @ quickstart ---
[INFO] 
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running com.dogzilla.maven.quickstart.AppTest
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.022 s - in com.dogzilla.maven.quickstart.AppTest
[INFO] 
[INFO] Results:
[INFO] 
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO] 
[INFO] 
[INFO] --- maven-jar-plugin:3.0.2:jar (default-jar) @ quickstart ---
[INFO] Building jar: /opt/workspace/eclipse/java/quickstart/target/quickstart-0.0.1-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  1.967 s
[INFO] Finished at: 2020-12-13T20:00:27-07:00
[INFO] ------------------------------------------------------------------------

java -cp /opt/workspace/eclipse/java/quickstart/target/quickstart-0.0.1-SNAPSHOT.jar com.dogzilla.maven.quickstart.App

Exception in thread "main" java.lang.NoClassDefFoundError: com/google/gson/Gson
        at com.dogzilla.maven.quickstart.App.main(App.java:13)
Caused by: java.lang.ClassNotFoundException: com.google.gson.Gson
        at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
        ... 1 more