我正在尝试开始我的第一次爬网，我已经配置了数据库设置，并执行了以下命令:< code>bin/nutch inject urls

错误结果如下:

InjectorJob: starting at 2014-07-18 08:13:34
InjectorJob: Injecting urlDir: urls
InjectorJob: Using class org.apache.gora.sql.store.SqlStore as the Gora storage class.
InjectorJob: java.lang.RuntimeException: job failed: name=inject urls, jobid=job_local1172062909_0001
        at org.apache.nutch.util.NutchJob.waitForCompletion(NutchJob.java:54)
        at org.apache.nutch.crawl.InjectorJob.run(InjectorJob.java:233)
        at org.apache.nutch.crawl.InjectorJob.inject(InjectorJob.java:251)
        at org.apache.nutch.crawl.InjectorJob.run(InjectorJob.java:273)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
        at org.apache.nutch.crawl.InjectorJob.main(InjectorJob.java:282)

有人可以帮助我吗？