中间碰到的问题，解决方法参考
http://blog.javachen.com/2014/05/20/nutch-intro/
问题1：
compile-core:
[javac] Compiling 180 source files to /root/nutch/build/classes
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._zipfs.jar; error in opening zip file
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._sunec.jar; error in opening zip file
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._sunjce_provider.jar; error in opening zip file
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._sunpkcs11.jar; error in opening zip file
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._jfxrt.jar; error in opening zip file
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._dnsns.jar; error in opening zip file
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._nashorn.jar; error in opening zip file
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._localedata.jar; error in opening zip file
[javac] error: error reading /usr/lib/jvm/jdk1.8.0_20/jre/lib/ext/._cldrdata.jar; error in opening zip file
[javac] warning: [options] bootstrap class path not set in conjunction with -source 1.6
[javac] 9 errors
[javac] 1 warning
BUILD FAILED
/root/nutch/build.xml:101: Compile failed; see the compiler error output for details.
原ext文件夹没有._这些jar，但是有同名zipfs,直接copy,编译通过;
问题2：
root@iZ280izbfjqZ:~/nutch/runtime/local# bin/nutch crawl urls -depth 3 -topN 5
Exception in thread "main" java.lang.ClassNotFoundException: org.apache.gora.sql.store.SqlStore
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:259)
at org.apache.nutch.storage.StorageUtils.getDataStoreClass(StorageUtils.java:90)
at org.apache.nutch.storage.StorageUtils.createWebStore(StorageUtils.java:74)
at org.apache.nutch.crawl.InjectorJob.run(InjectorJob.java:221)
at org.apache.nutch.crawl.Crawler.runTool(Crawler.java:68)
at org.apache.nutch.crawl.Crawler.run(Crawler.java:136)
at org.apache.nutch.crawl.Crawler.run(Crawler.java:250)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.nutch.crawl.Crawler.main(Crawler.java:257)
参考以下文章：
问题三：
root@iZ280izbfjqZ:~/nutch/runtime/local# bin/nutch crawl urls -depth 3 -topN 5
InjectorJob: Using class org.apache.gora.sql.store.SqlStore as the Gora storage class.
InjectorJob: total number of urls rejected by filters: 0
InjectorJob: total number of urls injected after normalization and filtering: 1
Exception in thread "main" java.lang.RuntimeException: job failed: name=generate: *, jobid=job_local1888916405_0002
at org.apache.nutch.util.NutchJob.waitForCompletion(NutchJob.java:55)
at org.apache.nutch.crawl.GeneratorJob.run(GeneratorJob.java:199)
at org.apache.nutch.crawl.Crawler.runTool(Crawler.java:68)
at org.apache.nutch.crawl.Crawler.run(Crawler.java:152)
at org.apache.nutch.crawl.Crawler.run(Crawler.java:250)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.nutch.crawl.Crawler.main(Crawler.java:257)
nutch/src/java/org/apache/nutch/crawl/GeneratorReducer.java，然后看其100行左右
batchId=new Utf8(conf.get(GeneratorJob.BATCH_ID));
改为：
int randomSeed = Math.abs(new Random().nextInt());
String batchIdStr = (System.currentTimeMillis()/1000)+"-"+randomSeed;
batchId = new Utf8( batchIdStr );
问题4.
解决
alter table webpage add batchId varchar(767) DEFAULT NULL;
然后就成功了，庆祝一下