需求：regexp_replace(字段wfss,’\’,’&’)
匹配wfss里数据包含反斜杠’’，然后再给它替换成’&’,
一开始我只给了两个反斜杠，运行会报错，
搜了一圈，需要四个才行：regexp_replace(字段wfss,’\\’,’&’)
后来配调度脚本的时候，加了hive -e"…"
结果报了如下错误：
Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Unable to execute method public org.apache.hadoop.io.Text org.apache.hadoop.hive.ql.udf.UDFRegExpReplace.evaluate(org.apache.hadoop.io.Text,org.apache.hadoop.io.Text,org.apache.hadoop.io.Text):Unexpected internal error near index 1
at org.apache.hadoop.hive.ql.exec.FunctionRegistry.invoke(FunctionRegistry.java:1120)
at org.apache.hadoop.hive.ql.udf.generic.GenericUDFBridge.evaluate(GenericUDFBridge.java:194)
at org.apache.hadoop.hive.ql.exec.vector.udf.VectorUDFAdaptor.setResult(VectorUDFAdaptor.java:190)
at org.apache.hadoop.hive.ql.exec.vector.udf.VectorUDFAdaptor.evaluate(VectorUDFAdaptor.java:150)
at org.apache.hadoop.hive.ql.exec.vector.VectorSelectOperator.process(VectorSelectOperator.java:146)
at org.apache.hadoop.hive.ql.exec.Operator.vectorForward(Operator.java:965)
at org.apache.hadoop.hive.ql.exec.Operator.forward(Operator.java:938)
at org.apache.hadoop.hive.ql.exec.vector.VectorFilterOperator.process(VectorFilterOperator.java:136)
at org.apache.hadoop.hive.ql.exec.Operator.vectorForward(Operator.java:965)
at org.apache.hadoop.hive.ql.exec.Operator.forward(Operator.java:938)
at org.apache.hadoop.hive.ql.exec.TableScanOperator.process(TableScanOperator.java:125)
at org.apache.hadoop.hive.ql.exec.vector.VectorMapOperator.deliverVectorizedRowBatch(VectorMapOperator.java:812)
at org.apache.hadoop.hive.ql.exec.vector.VectorMapOperator.process(VectorMapOperator.java:845)
… 20 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.hive.ql.exec.FunctionRegistry.invoke(FunctionRegistry.java:1096)
… 32 more
Caused by: java.util.regex.PatternSyntaxException: Unexpected internal error near index 1
at java.util.regex.Pattern.error(Pattern.java:1957)
at java.util.regex.Pattern.compile(Pattern.java:1704)
at java.util.regex.Pattern.(Pattern.java:1351)
at java.util.regex.Pattern.compile(Pattern.java:1028)
at org.apache.hadoop.hive.ql.udf.UDFRegExpReplace.evaluate(UDFRegExpReplace.java:57)
… 36 more
也就是说还是反斜杠造成的，
尝试了一根，两根，三根，四根，五根，六根
都TM不行，日乐购
后来想着既然四个才能匹配一根，那我试试八根吧，
结果八根，regexp_replace(字段wfss,’\\\\’,’&’)
就可以运行了！！！！
