使用java 9编译lambda表达式时，Maven构建失败

Question

我正在为maven spring boot构建一个示例，使用java 9，在使用maven build插件执行干净包时遇到编译错误。

java build path：选择JRE 9
Java编译器：启用项目特定设置（选为9）
Eclipse首选项：Java - > Installed JRE - > Selected JRE 9
运行配置：Workplace默认JRE（选择java 9）

不知道maven从哪里采摘1.6

pom.hml

<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>com.jaggs.springboot</groupId>
    <artifactId>HelloSpringBoot</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

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

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.ersion>1.9</java.ersion>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <source>1.9</source>
                    <target>1.9</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>