本文整理了Java中org.apache.flink.api.java.operators.UnsortedGrouping.maxBy()方法的一些代码示例，展示了UnsortedGrouping.maxBy()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。UnsortedGrouping.maxBy()方法的具体详情如下：
包路径：org.apache.flink.api.java.operators.UnsortedGrouping
类名称：UnsortedGrouping
方法名：maxBy

UnsortedGrouping.maxBy介绍

[英]Applies a special case of a reduce transformation (maxBy) on a grouped DataSet.

The transformation consecutively calls a ReduceFunctionuntil only a single element remains which is the result of the transformation. A ReduceFunction combines two elements into one new element of the same type.
[中]在分组数据集上应用reduce转换（maxBy）的特殊情况。
转换连续调用reduceFunction，直到只剩下一个元素，这是转换的结果。ReduceFunction将两个元素组合成一个相同类型的新元素。

代码示例

代码示例来源：origin: apache/flink

/**
 * This test validates that an InvalidProgramException is thrown when maxBy
 * is used on a custom data type.
 */
@Test(expected = InvalidProgramException.class)
public void testCustomKeyFieldsGrouping() {
  final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
  this.customTypeData.add(new CustomType());
  UnsortedGrouping<CustomType> groupDs = env.fromCollection(customTypeData).groupBy(0);
  // should not work: groups on custom type
  groupDs.maxBy(0);
}

代码示例来源：origin: apache/flink

/**
 * This test validates that an index which is out of bounds throws an
 * IndexOutOfBoundsException.
 */
@Test(expected = IndexOutOfBoundsException.class)
public void testOutOfTupleBoundsGrouping3() {
  final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
  UnsortedGrouping<Tuple5<Integer, Long, String, Long, Integer>> groupDs = env.fromCollection(emptyTupleData, tupleTypeInfo).groupBy(0);
  // should not work, key out of tuple bounds
  groupDs.maxBy(1, 2, 3, 4, -1);
}

代码示例来源：origin: apache/flink

/**
 * This test validates that an index which is out of bounds throws an
 * IndexOutOfBoundsException.
 */
@Test(expected = IndexOutOfBoundsException.class)
public void testOutOfTupleBoundsGrouping2() {
  final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
  UnsortedGrouping<Tuple5<Integer, Long, String, Long, Integer>> groupDs = env.fromCollection(emptyTupleData, tupleTypeInfo).groupBy(0);
  // should not work, key out of tuple bounds
  groupDs.maxBy(-1);
}

代码示例来源：origin: apache/flink

/**
 * This test validates that an index which is out of bounds throws an
 * IndexOutOfBoundsException.
 */
@Test(expected = IndexOutOfBoundsException.class)
public void testOutOfTupleBoundsGrouping1() {
  final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
  UnsortedGrouping<Tuple5<Integer, Long, String, Long, Integer>> groupDs = env.fromCollection(emptyTupleData, tupleTypeInfo).groupBy(0);
  // should not work, key out of tuple bounds
  groupDs.maxBy(5);
}

代码示例来源：origin: apache/flink

/**
 * This test validates that no exceptions is thrown when an empty grouping
 * calls maxBy().
 */
@Test
public void testMaxByKeyFieldsGrouping() {
  final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
  UnsortedGrouping<Tuple5<Integer, Long, String, Long, Integer>> groupDs = env.fromCollection(emptyTupleData, tupleTypeInfo).groupBy(0);
  // should work
  try {
    groupDs.maxBy(4, 0, 1, 2, 3);
  } catch (Exception e) {
    Assert.fail();
  }
}

代码示例来源：origin: seznam/euphoria

trendsParams.getRankThreshold()))
.groupBy(0)
.maxBy(2)
.setParallelism(1);