Java 即使JAR包含在类路径中，Eclipse类也未发现异常

从Eclipse在Biginsights服务器上运行java mapreduce程序会导致com.mysql.jdbc.Driver ClassNotFoundException，即使JAR包含在类路径中

错误：

The system encountered the following error while it was submitting the job:
15/03/26 18:59:29 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
15/03/26 18:59:29 INFO mapred.JobClient: Cleaning up the staging area hdfs://biginsights-node:9000/user/biadmin/.staging/job_201503261700_0014
Exception in thread "main" java.lang.RuntimeException: java.lang.RuntimeException: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at org.apache.hadoop.mapreduce.lib.db.DBInputFormat.setConf(DBInputFormat.java:164)
    at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:73)
    at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:133)
    at org.apache.hadoop.mapred.JobClient.writeNewSplits(JobClient.java:1079)
    at org.apache.hadoop.mapred.JobClient.writeSplits(JobClient.java:1099)
    at org.apache.hadoop.mapred.JobClient.access$700(JobClient.java:188)
    at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:1010)
    at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:963)
    at java.security.AccessController.doPrivileged(AccessController.java:366)
    at javax.security.auth.Subject.doAs(Subject.java:572)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1502)
    at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:963)
    at org.apache.hadoop.mapreduce.Job.submit(Job.java:616)
    at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:646)
    at example.DbExportMainClass.main(DbExportMainClass.java:51)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:94)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:55)
    at java.lang.reflect.Method.invoke(Method.java:619)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:212)
Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at org.apache.hadoop.mapreduce.lib.db.DBInputFormat.getConnection(DBInputFormat.java:190)
    at org.apache.hadoop.mapreduce.lib.db.DBInputFormat.setConf(DBInputFormat.java:158)
    ... 19 more
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at java.lang.Class.forNameImpl(Native Method)
    at java.lang.Class.forName(Class.java:199)
    at org.apache.hadoop.mapreduce.lib.db.DBConfiguration.getConnection(DBConfiguration.java:148)
    at org.apache.hadoop.mapreduce.lib.db.DBInputFormat.getConnection(DBInputFormat.java:184)
    ... 20 more

尝试了stackoverflow中针对类似问题的几乎所有建议

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任何建议都会有帮助。

您需要将jar包含在Biginsight lib文件夹中，才能将其作为Biginsight应用程序运行。还将路径添加到biginsights环境文件

默认位置：/opt/ibm/biginsights/IHC/lib

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要作为java应用程序运行，应将其添加到类路径。

类路径上有什么？Biginsights默认jar、JRE系统库、Mysql jar连接器。除了Mysql jar，所有其他jar都在加载。