Windows 环境下，Netbeans下导入Nutch1.2。
测试环境：
Nutch 1.2
Netbean7.4
Java 1.8.0_20
cygwin
安装步骤:
1.安装：Cygwin
•下载 Nutch1.2 （下载地址：http://archive.apache.org/dist/nutch/）
•按照教程进行安装 (教程地址: http://wiki.apache.org/nutch/NutchTutorial)
环境变量配置如下：
classpath： .;%JAVA_HOME%lib;%JAVA_HOME%lib ools.jar
JAVA_HOME： D:Program FilesJavajdk1.8.0_20
CATALINA_HOME： D: errySoftwareJavaapache-tomcat-7.0.55
ANT_HOME：D: erryWorkJavaapache-ant-1.9.4-binapache-ant-1.9.4
Path: %JAVA_HOME%in;%CATALINA_HOME%in;%CATALINA_HOME%lib;%ANT_HOME%in;%JAVA_HOME%jrein;
系统环境变量部分： Path：C:WindowsSystem32;D:cygwinin;
2.在Netbeans中创建项目
创建项目过程：
启动 Netbeans7.4 文件->新建项目->常规；
•选择“基于现有源代码的Java项目”->下一步，选择项目名称和项目文件夹，可以根据自己的需要自行指定；
•选择下一步，点击“源包文件夹”文本框右边的“添加文件夹”按钮，浏览文件目录选择Nutch安装目录下的src文件夹；
•点击完成，此时工程已经建立，当需要对项目进行配置才能实现代码的调试；
导入文件及Jar包过程：
•在左边的“项目”导航窗口中，选择库包，点击右键，选择属性，此时弹出项目属性配置窗口
•选择配置“库”，点击按钮“添加JAR/文件夹”，添加Nutch安装目录下的 "conf"目录下所有文件；
•继续将Nutch安装目录下“lib”和“plugin”文件夹中的所有JAR包添加进来，此处比较麻烦，因为Netbeans不能自动扫描到文件夹下所有的JAR包，必须手工将其添加进来。
此时，您可以选择左方“项目”导航窗口中的项目图标，点击右键，选择“生成项目”，项目应该能正确通过编译。您还需要对Nutch进行配置以调试Nutch的爬行代码。
配置 Nutch
在Nutch安装目录下，找到文件/conf/nutch-defaul.xml， 将其 "plugin.folders" 属性值改为"Nutch安装目录/src/plugin"
运行
在Nutch中运行Nutch爬虫
•选择左方“项目”导航窗口中的项目图标，点击右键，选择“属性”，在左方类别窗口中选择“运行”，对运行参数进行配置
•主类： 选择 org.apache.nutch.crawl.Crawl
•参数： 填入 urls/microsoft.txt -dir crawl -depth 3 -topN 50
•VM选项：填入 -Dhadoop.log.dir=logs -Dhadoop.log.file=hadoop.log
•点击“确定”按钮退出
•选择左方“项目”导航窗口中的项目图标，点击右键，选择“运行项目”
运行过程中出现的错误及解决办法：
1 mapred.JobClient - No job jar file set. User classes may not be found. See JobConf(Class) or JobConf#setJar(String).
2014-10-17 13:20:45,384 INFO crawl.Crawl - crawl started in: crawl
2014-10-17 13:20:45,384 INFO crawl.Crawl - rootUrlDir = urls/microsoft_de-DE.txt
2014-10-17 13:20:45,384 INFO crawl.Crawl - threads = 10
2014-10-17 13:20:45,384 INFO crawl.Crawl - depth = 3
2014-10-17 13:20:45,384 INFO crawl.Crawl - indexer=lucene
2014-10-17 13:20:45,384 INFO crawl.Crawl - topN = 50
2014-10-17 13:20:59,721 INFO crawl.Injector - Injector: starting at 2014-10-17 13:20:55
2014-10-17 13:21:00,719 INFO crawl.Injector - Injector: crawlDb: crawl/crawldb
2014-10-17 13:21:01,530 INFO crawl.Injector - Injector: urlDir: urls/microsoft_de-DE.txt
2014-10-17 13:21:11,187 INFO crawl.Injector - Injector: Converting injected urls to crawl db entries.
2014-10-17 13:21:45,241 WARN mapred.JobClient - Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
2014-10-17 13:21:45,850 WARN mapred.JobClient - No job jar file set. User classes may not be found. See JobConf(Class) or JobConf#setJar(String).
出错原因：找不到Mapper类和Reduce类。
解决办法：
将本工程导出jar包放到工程根目录下面，并在Crawl.java类中获取到配置文件后重新加载mapred.jar包。
conf.set("mapred.jar", "NutchSource.jar"); NutchSource.jar是Nutch项目编译后的Jar包。
代码如下： public static void main(String args[]) throws Exception {
if (args.length < 1) {
System.out.println
("Usage: Crawl <urlDir> [-dir d] [-threads n] [-depth i] [-topN N]" +
" [-solr solrURL]");
return;
}
Configuration conf = NutchConfiguration.createCrawlConfiguration();
conf.set("mapred.jar", "NutchSource.jar");
JobConf job = new NutchJob(conf);
2. WARN plugin.PluginRepository - Plugins: directory not found: plugins
2014-10-17 13:43:29,729 INFO crawl.Crawl - crawl started in: crawl
2014-10-17 13:43:29,741 INFO crawl.Crawl - rootUrlDir = urls/microsoft_de-DE.txt
2014-10-17 13:43:29,743 INFO crawl.Crawl - threads = 10
2014-10-17 13:43:29,744 INFO crawl.Crawl - depth = 3
2014-10-17 13:43:29,745 INFO crawl.Crawl - indexer=lucene
2014-10-17 13:43:29,747 INFO crawl.Crawl - topN = 50
2014-10-17 13:43:32,080 INFO crawl.Injector - Injector: starting at 2014-10-17 13:43:32
2014-10-17 13:43:32,083 INFO crawl.Injector - Injector: crawlDb: crawl/crawldb
2014-10-17 13:43:32,085 INFO crawl.Injector - Injector: urlDir: urls/microsoft_de-DE.txt
2014-10-17 13:43:32,220 INFO crawl.Injector - Injector: Converting injected urls to crawl db entries.
2014-10-17 13:43:45,367 WARN mapred.JobClient - Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
2014-10-17 13:43:57,923 WARN plugin.PluginRepository - Plugins: directory not found: plugins
2014-10-17 13:43:57,924 INFO plugin.PluginRepository - Plugin Auto-activation mode: [true]
2014-10-17 13:43:57,924 INFO plugin.PluginRepository - Registered Plugins:
2014-10-17 13:43:57,929 INFO plugin.PluginRepository - NONE
2014-10-17 13:43:57,930 INFO plugin.PluginRepository - Registered Extension-Points:
2014-10-17 13:43:57,930 INFO plugin.PluginRepository - NONE
2014-10-17 13:43:58,010 WARN mapred.LocalJobRunner - job_local_0001
java.lang.RuntimeException: Error in configuring object
at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:93)
at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:64)
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:117)
at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:354)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:307)
at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:177)
Caused by: java.lang.reflect.InvocationTargetException
出错原因：找不到plugins此目录。
解决办法:查看conf目录下的nutch-default.xml中的plugin.folders的Value值在项目路径下是否存在。
<property>
<name>plugin.folders</name>
<value>plugins</value>
<description>Directories where nutch plugins are located. Each
element may be a relative or absolute path. If absolute, it is used
as is. If relative, it is searched for on the classpath.</description>
</property>
把此值改为项目下src/plugin.