如何检查freestyle作业的jenkins工作区中是否存在文件

if [ -f example.txt ]; then
    echo "File exists"
else
    echo "File does not exist"
fi

pipeline {
    agent any

    stages {
        stage('Check File') {
            steps {
                script {
                    def fileExists = fileExists('example.txt')
                    if (fileExists) {
                        echo "File exists"
                    } else {
                        echo "File does not exist"
                    }
                }
            }
        }
    }
}

def fileExists(filePath) {
    def file = new File(filePath)
    return file.exists()
}