Maven 运行具有依赖项的项目

Question

我找到了run main class 的问题，但没有找到当项目有多个依赖项时如何运行主类的问题。

我的项目遵循 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.onbrains</groupId>
    <artifactId>ExportQueryResult</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>

        <dependency>
            <groupId>com.oracle</groupId>
            <artifactId>ojdbc6</artifactId>
            <version>11.2.0.1.0</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/ojdbc6.jar</systemPath>
        </dependency>

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.9</version>
        </dependency>

        <dependency>
            <groupId>javax.enterprise</groupId>
            <artifactId>cdi-api</artifactId>
            <version>1.2</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <configuration>
                    <mainClass>Runner</mainClass>
                </configuration>
            </plugin>
            <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>
        </plugins>
    </build>

</project>

但是当我尝试从 maven 运行主类时：

mvn exec:java

我得到以下异常：

[INFO] Scanning for projects...
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for org.onbrains:ExportQueryResult:jar:1.0-SNAPSHOT
[WARNING] 'dependencies.dependency.systemPath' for com.oracle:ojdbc6:jar should not point at files within the project directory, ${basedir}/lib/ojdbc6.jar will be unresolvable by dependent projects @ line 18, column 25
[WARNING] 'build.plugins.plugin.version' for org.codehaus.mojo:exec-maven-plugin is missing. @ line 42, column 21
[WARNING] 
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING] 
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING] 
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building ExportQueryResult 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- exec-maven-plugin:1.4.0:java (default-cli) @ ExportQueryResult ---
oracle.jdbc.OracleDriver
[WARNING] 
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:293)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at query.QueryUtils.executeQuery(QueryUtils.java:41)
    at Runner.main(Runner.java:41)
    ... 6 more
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.008 s
[INFO] Finished at: 2015-12-03T15:15:08+03:00
[INFO] Final Memory: 10M/304M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.4.0:java (default-cli) on project ExportQueryResult: An exception occured while executing the Java class. null: InvocationTargetException: NullPointerException -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

Answer 1

我认为您的本地 maven 存储库中缺少 oracle jdbc jar。直接从 mvn 存储库下载 jar，因为它会将 oracle jar 添加到本地 maven 存储库。

下面是oracle jdbc的依赖sn-p

<dependency>
   <groupId>ojdbc</groupId>
   <artifactId>ojdbc</artifactId>
   <version>14</version>
</dependency>

根据您的需要更改版本。

如果您已经有一个现有的 jar，请添加到本地 maven 存储库。

无论如何，您必须从您的依赖项中删除 <systemPath> 标签。

Answer 2

尝试添加类路径：

 <arguments>
            <argument>-Dmyproperty=myvalue</argument>
            <argument>-classpath</argument>
            <classpath/>
            <argument>Runner</argument>
            ...
 </arguments>