PHPUnit和Symfony2无法访问全局变量

这是我的phpunit.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!-- http://phpunit.de/manual/4.1/en/appendixes.configuration.html -->
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/4.1/phpunit.xsd"
         backupGlobals="false"
         backupStaticAttributes="false"
         processIsolation="false"
         colors="true"
         stopOnFailure="false"
         syntaxCheck="false"
         bootstrap="bootstrap.php.cache"
         convertErrorsToExceptions="true"
         convertNoticesToExceptions="true"
         convertWarningsToExceptions="true"
>
    <testsuites>
        <testsuite name="Project Test Suite">
            <directory>../src/*/*Bundle/Tests</directory>
            <directory>../src/*/Bundle/*Bundle/Tests</directory>
            <directory>../src/*Bundle/Tests</directory>
        </testsuite>
    </testsuites>
    <php>
        <server name="KERNEL_DIR" value="./" />
        <var name="DB_DSN" value="mysql:dbname=test_xxx;host=localhost" />
        <var name="DB_USER" value="root" />
        <var name="DB_PASSWD" value="" />
        <var name="DB_DBNAME" value="test_xxx" /> 
    </php>

    <logging>
        <log type="coverage-html" target="build/coverage" title="App Code Coverage" charset="UTF-8" yui="true" highlight="true"
        lowUpperBound="35" highLowerBound="70"/>
        <log type="coverage-clover" target="build/logs/clover.xml"/>
        <log type="junit" target="build/logs/junit.xml" logIncompleteSkipped="false"/>
    </logging>
    <filter>
        <whitelist>
            <directory>../src</directory>
            <exclude>
                <directory>../src/*Bundle/Resources</directory>
                <directory>../src/*Bundle/Tests</directory>
                <directory>../src/*/*Bundle/Resources</directory>
                <directory>../src/*/*Bundle/Tests</directory>
                <directory>../src/*/Bundle/*Bundle/Resources</directory>
                <directory>../src/*/Bundle/*Bundle/Tests</directory>
            </exclude>
        </whitelist>
    </filter>
</phpunit>

在我的：

• src
  • AppBundle
    • 测试
      • AbstractDatabaseTestCase.php

AbstractDatabaseTestCase.php：

abstract class AbstractDatabaseTestCase extends 'PHPUnit_Extensions_Database_TestCase{
    /**
     * 
     *@var PDO 
     * 
     */
    static $pdo;
    /**
     * 
     *@var 'Doctrine'DBAL'Connection description 
     * 
     */
    static $dbal;
    private $conn;
    final public function getConnection()
    {
        var_dump($GLOBALS);
 // here my GLOBALS['DB_DSN'], GLOBALS['DB_USER'], GLOBALS['DB_PASSWD'] are not seen.
        if ($this->conn === null) {
            if (self::$pdo == null) {
                self::$pdo = new 'PDO( $GLOBALS['DB_DSN'], $GLOBALS['DB_USER'], $GLOBALS['DB_PASSWD'] );
            }
            $this->conn = $this->createDefaultDBConnection(self::$pdo, $GLOBALS['DB_DBNAME']);
        }
        return $this->conn;
    }

正如您从注释中看到的，考虑到我遵循了文档的事实，我的类似乎没有看到phpunit.xml文件中定义的全局变量。

你有什么想法吗？我错过什么了吗？

谢谢！