Maven surefire插件，在构建生命周期中设置和获取系统属性

Question

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <configuration>
        <forkCount>2</forkCount>
        <reuseForks>true</reuseForks>
        <argLine>-Xmx1024m -XX:MaxPermSize=256m</argLine>
        <systemPropertyVariables>
            <databaseSchema>test_schema_${surefire.forkNumber}</databaseSchema>
        </systemPropertyVariables>
    </configuration>
</plugin>

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>sql-maven-plugin</artifactId>
    <version>1.5</version>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql-connector-java.version}</version>
        </dependency>
    </dependencies>
    <configuration>
        <driver>com.mysql.jdbc.Driver</driver>
        <username>user_with_create_privs</username>
        <password>password</password>
        <url>jdbc:mysql://localhost/dummy_schema</url>
    </configuration>
    <executions>
        <execution>
            <id>create-db</id>
            <phase>process-test-classes</phase>
            <goals>
                <goal>execute</goal>
            </goals>
            <configuration>
                <url>jdbc:mysql://localhost/dummy_schema</url>
                <autocommit>true</autocommit>
                <sqlCommand>create database ${databaseSchema}</sqlCommand>
            </configuration>
        </execution>
    </executions>
</plugin>

mvn test

结果输出：

[DEBUG] SQL:  drop database ${databaseSchema}
[ERROR] Failed to execute:  drop database ${databaseSchema}
[ERROR] Failed to execute goal org.codehaus.mojo:sql-maven-plugin:1.5:execute
(create-db) on project billing-core: You have an error in your SQL syntax; check
the manual that corresponds to your MySQL server version for the right
syntax to use near '{databaseSchema}' at line 1 -> [Help 1]

因此，看起来${databaseSchema}没有被填充，或者是语法问题。我拉过小提琴，但不能让这个工作，尽管它看起来很容易，也应该。

Answer 1

您可能混淆了Maven的属性、Java系统属性和环境变量。您希望使用的变量看起来像Maven属性。

您可以在properties元素中定义POM中的属性。此外，您可以使用${env.PropertyName}表单引用环境变量，并使用${Java.PropertyName}表单引用Java系统属性。

有关更多信息，您可以参考以下内容:https://maven.apache.org/pom.html#properties