diff --git a/ql/src/java/org/apache/hadoop/hive/ql/exec/UDAF.java b/ql/src/java/org/apache/hadoop/hive/ql/exec/UDAF.java index 8d3c942..39f83a1 100755 --- a/ql/src/java/org/apache/hadoop/hive/ql/exec/UDAF.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/exec/UDAF.java @@ -19,35 +19,58 @@ package org.apache.hadoop.hive.ql.exec; /** + * Please see the deprecation notice + *

* Base class for all User-defined Aggregation Function (UDAF) classes. - * + *

* UDAF classes are REQUIRED to inherit from this class. - * - * Required for a UDAF class: 1. Implement the init() method, which reset the - * status of the aggregation function. 2. Implement a single method called - * "aggregate" that returns boolean. The method should always return "true" on - * valid inputs, or the framework will throw an Exception. Following are some - * examples: public boolean aggregate(double a); public boolean aggregate(int - * b); public boolean aggregate(double c, double d); 3. Implement a single - * method called "evaluate" that returns the FINAL aggregation result. - * "evaluate" should never return "null" or an Exception will be thrown. - * Following are some examples. public int evaluate(); public long evaluate(); - * public double evaluate(); public Double evaluate(); public String evaluate(); - * - * Optional for a UDAF class (by implementing these 2 methods, the user declares - * that the UDAF support partial aggregations): 1. Implement a single method - * called "evaluatePartial" that returns the PARTIAL aggregation result. - * "evaluatePartial" should never return "null" or an Exception will be thrown. - * 2. Implement a single method called "aggregatePartial" that takes a PARTIAL - * aggregation result and returns a boolean. The method should always return - * "true" on valid inputs, or the framework will throw an Exception. - * - * Following are some examples: public int evaluatePartial(); public boolean - * aggregatePartial(int partial); - * - * public String evaluatePartial(); public boolean aggregatePartial(String - * partial); - * + *

+ * Required for a UDAF class: + *

    + *
  1. Implement the {@code init()} method, which resets the status of the aggregation function.
  2. + *
  3. Implement a single method called {@code aggregate} that returns {@code boolean}. + * The method should always return {@code true} on valid inputs, or the framework will throw an Exception. + * Following are some examples: + * + *
  4. + *
  5. Implement a single method called {@code evaluate} that returns the FINAL aggregation result. + * {@code evaluate} should never return {@code null} or an Exception will be thrown. + * Following are some examples: + * + *
  6. + *
+ * + * Optional for a UDAF class (by implementing these two methods, the user declares + * that the UDAF supports partial aggregations): + *
    + *
  1. Implement a single method called {@code evaluatePartial} that returns the PARTIAL aggregation result. + * {@code evaluatePartial} should never return {@code null} or an Exception will be thrown.
  2. + *
  3. Implement a single method called {@code aggregatePartial} that takes a PARTIAL + * aggregation result and returns a boolean. The method should always return + * {@code true} on valid inputs, or the framework will throw an Exception.
  4. + *
+ *

+ * Following are some examples: + *

+ *

+ * + * @deprecated Either implement {@link org.apache.hadoop.hive.ql.udf.generic.GenericUDAFResolver2} or extend + * {@link org.apache.hadoop.hive.ql.udf.generic.AbstractGenericUDAFResolver} instead. */ @Deprecated public class UDAF {