public void setFileSystemId(String fileSystemId) {
        this.fileSystemId = fileSystemId;
    }
<p>
The ID of the file system that you want to update.
</p>

@param fileSystemId
       The ID of the file system that you want to update.
aws-java-sdk-efs/src/main/java/com/amazonaws/services/elasticfilesystem/model/UpdateFileSystemRequest.java