行家.-source 1.5不支持lambda表达式

Question

我使用maven来构建我的项目.

我有以下配置:

D:\ freelance\polyndrom> mvn -verion Apache Maven 3.2.3(33f8c3e1027c3ddde99d3cdebad2656a31e8fdf4; 2014-08-12T00:58:1 0 + 04:00)Maven home:C:\ Program Files\apache\apache-maven-3.2. 3 Java版本:1.8.0_25,供应商:Oracle Corporation Java home:C:\ Program Files\Java\jdk1.8.0_25\jre默认语言环境:ru_RU,平台编码:Cp1251操作系统名称:"windows 7",版本:"6.1 ",arch:"amd64",家庭:"dos"

但是当我编译项目时,我看到以下错误:

lambda expressions are not supported in -source 1.5

我很困惑 - 我看到我使用java 8.

pom.xml中:

<?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>polyndrom</groupId>
    <artifactId>polyndrom</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-all</artifactId>
            <version>1.8.4</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                            <mainClass>com.peterservice.polyndrom.Main</mainClass>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>           
        </plugins>
    </build>
</project>

Answer 1

默认情况下,Maven假定您使用JDK 1.5编写代码并且要编译到同一目标.您需要将maven-compiler-plugin添加到构建插件中,以告诉它使用1.8.

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.3</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

查看插件的文档了解更多信息:http://maven.apache.org/plugins/maven-compiler-plugin/compile-mojo.html

Answer 2

您可以在属性中指定语言版本

<properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
</properties>