Maven给出错误:-source 1.5不支持try-with-resources

时间:2013-06-25 14:26:42

标签: java maven

尝试使用IntelliJ 12.1.4和Java 7创建一个使用Maven 3.0.5的jar时出错。我能够通过IDE运行项目没有任何问题,但是当我尝试打包它时,我得到了以下错误。

我的POM的相关部分(摘自Maven By Example Sonatype):

<build>
    <plugins>
        <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <configuration>
                <descriptorRefs>jar-with-dependencies</descriptorRefs>
            </configuration>
        </plugin>
    </plugins>
</build>

,错误是:

[ERROR] ...[33,55] error: diamond operator is not supported in -source 1.5
[ERROR] ...[207,7] error: try-with-resources is not supported in -source 1.5
[ERROR] ...[73,52] error: diamond operator is not supported in -source 1.5
[ERROR] ...[129,40] error: multi-catch statement is not supported in -source 1.5
[ERROR] ...[44,6] error: try-with-resources is not supported in -source 1.5
[ERROR] ...[28,39] error: diamond operator is not supported in -source 1.5
[ERROR] ...[31,7] error: try-with-resources is not supported in -source 1.5
[ERROR] ...[38,6] error: try-with-resources is not supported in -source 1.5
[ERROR] ...[34,41] error: diamond operator is not supported in -source 1.5
[ERROR] ...[77,43] error: diamond operator is not supported in -source 1.5
[ERROR] ...[84,6] error: try-with-resources is not supported in -source 1.5
[ERROR] ...[281,38] error: diamond operator is not supported in -source 1.5
[ERROR] ...[13,55] error: diamond operator is not supported in -source 1.5
[ERROR] ...[155,7] error: try-with-resources is not supported in -source 1.5

如何让maven使用source 1.7?

1 个答案:

答案 0 :(得分:43)

要回答第一部分,请将以下行添加到POM以设置语言级别

 <properties>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
</properties>

添加这些行后,您可以成功构建jar,但是当您运行它时,您的jar会出现no main manifest attribute错误。

这可以通过像java -cp app.jar com.somepackage.SomeClass

那样运行来修复

或者纠正这个并制作一个可执行的jar,让你的pom看起来像

 <build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <executions>
                <execution>
                    <id>copy-dependencies</id>
                    <phase>prepare-package</phase>
                    <goals>
                        <goal>copy-dependencies</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>${project.build.directory}/lib</outputDirectory>
                        <overWriteReleases>false</overWriteReleases>
                        <overWriteSnapshots>false</overWriteSnapshots>
                        <overWriteIfNewer>true</overWriteIfNewer>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <configuration>
                <archive>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <classpathPrefix>lib/</classpathPrefix>
                        <mainClass>fully.qualified.main</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>

这个pom通过将依赖项复制到构建目录,然后使用包含的库创建jar来克服jar-with-dependencies descriptorRef的一些问题。

感谢@André Aronsen了解他的pom解决方案。

关于没有主要的清单错误,有很多关于这个问题的帖子,有些解决方案有效,有些则没有。这个解决方案对我有用,所以我已将它包含在这篇文章中以供完成。

使用Java 7,Maven 3.0.5和JetBrains IntelliJ IDEA 12.1.4 Ultimate测试。