Question

尝试使用maven从命令行运行Java7 Hello World Project。如果我在eclipse中运行代码，我的项目运行正常，但如果我尝试执行“mvn packege”包，我会收到以下错误..

这是我的来源：

public class App 
{
    public static void main( String[] args )
    {
        System.out.println( "Hello World!, Tesing Java 7" );
        printDay("Wednesday");
    }

    public static void printDay(String dayOfWeek) {
        switch (dayOfWeek) 
        {
            case "Sunday": System.out.println("Dimanche"); break;
            case "Monday": System.out.println("Lundi"); break;
            case "Tuesday": System.out.println("Mardi"); break;
            case "Wednesday": System.out.println("Mercredi"); break;
            case "Thursday": System.out.println("Jeudi"); break;
            case "Friday": System.out.println("Vendredi"); break;
            case "Saturday": System.out.println("Samedi"); break;

            default: System.out.println("Error: '"+ dayOfWeek +"' is not a day of the week"); break;
        }
    }
}

这是我的pom.xml文件：

<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.smith</groupId>
  <artifactId>TestJava7</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>TestJava7</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

这是错误：

[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /home/jsmith/Documents/workspace-juno/TestJava7/src/main/java/org/smith/TestJava7/App.java:[16,13] error: strings in switch are not supported in -source 1.5
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.169s
[INFO] Finished at: Wed Jan 16 09:48:26 EST 2013
[INFO] Final Memory: 10M/100M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project TestJava7: Compilation failure
[ERROR] /home/jsmith/Documents/workspace-juno/TestJava7/src/main/java/org/smith/TestJava7/App.java:[16,13] error: strings in switch are not supported in -source 1.5
[ERROR] -> [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/MojoFailureException

Answer 1

设置编译器插件的源和目标版本：

http://maven.apache.org/plugins/maven-compiler-plugin/

<project>
  [...]
  <build>
    [...]
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.0</version>
        <configuration>
          <source>1.7</source>
          <target>1.7</target>
        </configuration>
      </plugin>
    </plugins>
    [...]
  </build>
  [...]
</project>

Answer 2

错误显然是在说：

strings in switch are not supported in -source 1.5

您需要将maven-compiler-plugin配置为指向JDK 7，默认情况下它将指向1.5或1.6

尝试Here for more information了解如何配置相同内容。

Answer 3

将maven插件添加到POM.xml中，清理并重新运行..

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>3.0</version>
  <configuration>
    <source>1.7</source>
    <target>1.7</target>
  </configuration>
</plugin>

尝试使用maven从命令行运行Java7 Hello World Project

3 个答案: