Question

我正在尝试使用Maven在我的服务器（CentOS）中创建.jar文件。它成功编译并生成.jar文件。但是当我执行它时，它显示以下错误。这个问题可能看起来像“之前被问到”但是，我尝试了这里的所有建议。我认为在我的POM.xml中有一些问题，但我无法找到。如果有人可以验证POM.xml，那将会有所帮助。

命令：

$ java -jar target/ListDescCrawler-1.1-SNAPSHOT.jar

错误：

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

我的POM.xml

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>edu.uci.ics.crawler4j</groupId>
  <artifactId>ListDescCrawler</artifactId>
  <packaging>jar</packaging>
  <version>1.1-SNAPSHOT</version>
  <name>SanListDescCrawlerHandu</name>
  <url>http://maven.apache.org</url>
  <build>
      <pluginManagement>
        <plugins>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.3</version>
            <configuration>
              <source>1.7</source>
              <target>1.7</target>            
            </configuration>
          </plugin>
          <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                            <mainClass>edu.uci.ics.crawler4j.example.MainController</mainClass>                         
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
        </plugins>
      </pluginManagement>
  </build>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.james</groupId>
        <artifactId>apache-mime4j-core</artifactId>
        <version>0.7</version>
    </dependency>
    <dependency>
        <groupId>org.apache.james</groupId>
        <artifactId>apache-mime4j-dom</artifactId>
        <version>0.7</version>
    </dependency>
    <dependency>
        <groupId>asm</groupId>
        <artifactId>asm</artifactId>
        <version>3.1</version>
    </dependency>
    <dependency>
        <groupId>de.l3s.boilerpipe</groupId>
        <artifactId>boilerpipe</artifactId>
        <version>1.1.0</version>
    </dependency>
    <dependency>
        <groupId>commons-codec</groupId>
        <artifactId>commons-codec</artifactId>
        <version>1.6</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-compress</artifactId>
        <version>1.3</version>
    </dependency>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.1.3</version>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>fluent-hc</artifactId>
        <version>4.3.6</version>
    </dependency>
    <dependency>
        <groupId>org.apache.geronimo.specs</groupId>
        <artifactId>geronimo-stax-api_1.0_spec</artifactId>
        <version>1.0.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.3.6</version>
    </dependency>   
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpcore</artifactId>
        <version>4.3.3</version>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpmime</artifactId>
        <version>4.3.6</version>
    </dependency>
    <dependency>
        <groupId>com.sleepycat</groupId>
        <artifactId>je</artifactId>
        <version>4.0.92</version>
    </dependency>
    <dependency>
        <groupId>org.jsoup</groupId>
        <artifactId>jsoup</artifactId>
        <version>1.8.1</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
    <dependency>
        <groupId>com.drewnoakes</groupId>
        <artifactId>metadata-extractor</artifactId>
        <version>2.4.0-beta-1</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.34</version>
    </dependency>
    <dependency>
        <groupId>org.ccil.cowan.tagsoup</groupId>
        <artifactId>tagsoup</artifactId>
        <version>1.2.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.tika</groupId>
        <artifactId>tika-app</artifactId>
        <version>1.6</version>
    </dependency>
  </dependencies>
</project>

生成的.jar文件中的MANIFEST.MF文件：

Manifest-Version: 1.0
Archiver-Version: Plexus Archiver
Created-By: Apache Maven
Built-By: root
Build-Jdk: 1.7.0_91
Main-Class: edu.uci.ics.crawler4j.example.MainController
Class-Path: apache-mime4j-core-0.7.jar apache-mime4j-dom-0.7.jar asm-3
 .1.jar boilerpipe-1.1.0.jar commons-codec-1.6.jar commons-compress-1.
 3.jar commons-logging-1.1.3.jar fluent-hc-4.3.6.jar geronimo-stax-api
 _1.0_spec-1.0.1.jar httpclient-4.3.6.jar httpcore-4.3.3.jar httpmime-
 4.3.6.jar je-4.0.92.jar jsoup-1.8.1.jar log4j-1.2.17.jar metadata-ext
 ractor-2.4.0-beta-1.jar tagsoup-1.2.1.jar tika-app-1.6.jar tika-parse
 rs-1.6.jar tika-core-1.6.jar vorbis-java-tika-0.6.jar netcdf-4.2.20.j
 ar unidataCommon-4.2.20.jar jcip-annotations-1.0.jar commons-httpclie
 nt-3.1.jar jmatio-1.0.jar xz-1.5.jar pdfbox-1.8.6.jar fontbox-1.8.6.j
 ar jempbox-1.8.6.jar bcmail-jdk15-1.45.jar bcprov-jdk15-1.45.jar poi-
 3.11-beta2.jar poi-scratchpad-3.11-beta2.jar poi-ooxml-3.11-beta2.jar
  poi-ooxml-schemas-3.11-beta2.jar xmlbeans-2.6.0.jar asm-debug-all-4.
 1.jar isoparser-1.0.2.jar aspectjrt-1.8.0.jar rome-1.0.jar jdom-1.0.j
 ar vorbis-java-core-0.6.jar juniversalchardet-1.0.3.jar jhighlight-1.
 0.jar java-libpst-0.8.1.jar tika-serialization-1.6.jar tika-xmp-1.6.j
 ar xmpcore-5.1.2.jar slf4j-log4j12-1.5.6.jar slf4j-api-1.5.6.jar gson
 -1.7.1.jar

执行的命令：

 mvn clean compile
 mvn clean package
 java -jar target/ListDescCrawler-1.1-SNAPSHOT.jar

项目中添加了许多库文件，包括mysql-connector-java-5.1.34.jar。但仍然出现错误。我检查了SOF的解决方案，并从这里尝试了很多建议，但没有解决我的问题。

我在生成的.jar文件中检查了MANIFEST.MF，看起来很好。

需要注意的其他要点是，Eclipse的工作正常（没有Maven）

我的POM.xml中有错误吗？

我尝试的建议：

依赖/范围我尝试了所有可能的值
在lib文件夹中复制mysql-connector-java-5.1.34.jar并相应地更改了POM.xml

可能还有其他建议，但没有任何帮助。

最后，事情开始使用以下POM.xml

<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>edu.uci.ics.crawler4j</groupId>
    <artifactId>ListDescCrawler</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>SanListDescCrawlerHandu</name>
    <url>http://maven.apache.org</url>

    <properties>
        <jdk.version>1.7</jdk.version>      
        <junit.version>4.11</junit.version>
        <apache-mime4j-core.version>0.7</apache-mime4j-core.version>
        <apache-mime4j-dom.version>0.7</apache-mime4j-dom.version>
        <asm.version>3.1</asm.version>
        <boilerpipe.version>1.1.0</boilerpipe.version>
        <commons-codec.version>1.6</commons-codec.version>
        <commons-compress.version>1.3</commons-compress.version>
        <commons-logging.version>1.1.3</commons-logging.version>
        <fluent-hc.version>4.3.6</fluent-hc.version>
        <geronimo-stax-api_1.0_spec.version>1.0.1</geronimo-stax-api_1.0_spec.version>
        <httpclient.version>4.3.6</httpclient.version>
        <httpcore.version>4.3.3</httpcore.version>
        <httpmime.version>4.3.6</httpmime.version>
        <je.version>4.0.92</je.version>
        <jsoup.version>1.8.1</jsoup.version>
        <log4j.version>1.2.17</log4j.version>
        <metadata-extractor.version>2.4.0-beta-1</metadata-extractor.version>
        <mysql-connector-java.version>5.1.34</mysql-connector-java.version>
        <tagsoup.version>1.2.1</tagsoup.version>
        <tika-app.version>1.6</tika-app.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.james</groupId>
            <artifactId>apache-mime4j-core</artifactId>
            <version>${apache-mime4j-core.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.james</groupId>
            <artifactId>apache-mime4j-dom</artifactId>
            <version>${apache-mime4j-dom.version}</version>
        </dependency>
        <dependency>
            <groupId>asm</groupId>
            <artifactId>asm</artifactId>
            <version>${asm.version}</version>
        </dependency>
        <dependency>
            <groupId>de.l3s.boilerpipe</groupId>
            <artifactId>boilerpipe</artifactId>
            <version>${boilerpipe.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>${commons-codec.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-compress</artifactId>
            <version>${commons-compress.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>${commons-logging.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>fluent-hc</artifactId>
            <version>${fluent-hc.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.geronimo.specs</groupId>
            <artifactId>geronimo-stax-api_1.0_spec</artifactId>
            <version>${geronimo-stax-api_1.0_spec.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>${httpclient.version}</version>
        </dependency>   
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpcore</artifactId>
            <version>${httpcore.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpmime</artifactId>
            <version>${httpmime.version}</version>
        </dependency>
        <dependency>
            <groupId>com.sleepycat</groupId>
            <artifactId>je</artifactId>
            <version>${je.version}</version>
        </dependency>
        <dependency>
            <groupId>org.jsoup</groupId>
            <artifactId>jsoup</artifactId>
            <version>${jsoup.version}</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>
        <dependency>
            <groupId>com.drewnoakes</groupId>
            <artifactId>metadata-extractor</artifactId>
            <version>${metadata-extractor.version}</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql-connector-java.version}</version>
        </dependency>
        <dependency>
            <groupId>org.ccil.cowan.tagsoup</groupId>
            <artifactId>tagsoup</artifactId>
            <version>${tagsoup.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tika</groupId>
            <artifactId>tika-app</artifactId>
            <version>${tika-app.version}</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>ListDescCrawler</finalName>
        <plugins>

            <!-- download source code in Eclipse, best practice -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-eclipse-plugin</artifactId>
                <version>2.9</version>
                <configuration>
                    <downloadSources>true</downloadSources>
                    <downloadJavadocs>false</downloadJavadocs>
                </configuration>
            </plugin>           

            <!-- Set a compiler level -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>${jdk.version}</source>
                    <target>${jdk.version}</target>
                </configuration>
            </plugin>

            <!-- Maven Assembly Plugin -->
            <plugin>
              <artifactId>maven-assembly-plugin</artifactId>
              <configuration>
                <descriptorRefs>
                  <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
                <archive>
                  <manifest>
                    <mainClass>edu.uci.ics.crawler4j.example.MainController</mainClass>
                  </manifest>
                </archive>
              </configuration>
              <executions>
                <execution>
                  <phase>package</phase>
                  <goals>
                    <goal>single</goal>
                  </goals>
                </execution>
              </executions>
            </plugin>

        </plugins>
    </build>

</project>

Answer 1

尽管MANIFEST.MF中的类路径包含您依赖的jar，但这并不意味着它们在您运行项目时实际上在您的类路径上。这里有两个选项，要么将所有依赖的jar放在runnable jar的同一目录中，要么创建一个带阴影的jar。

阴影（胖）jar包含所有依赖项。您可以使用maven创建阴影jar。这是一个例子。

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <version>2.4.1</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                    <configuration>
                        <finalName>${project.build.finalName}-with-dependencies</finalName>
                        <transformers>
                            <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                <mainClass> edu.uci.ics.crawler4j.example.MainController </mainClass>
                            </transformer>
                        </transformers>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

java.lang.ClassNotFoundException：com.mysql.jdbc.Driver for Maven runnable jar

1 个答案: