帮我实现一个flink的hash join 需要有代码
时间: 2023-06-11 15:05:40 浏览: 45
好的,以下是一个简单的 Flink Hash Join 的示例代码:
```
import org.apache.flink.api.common.functions.FlatJoinFunction;
import org.apache.flink.api.common.functions.JoinFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.api.java.operators.FlatJoinOperator;
import org.apache.flink.api.java.operators.JoinOperator;
import org.apache.flink.api.java.tuple.Tuple2;
public class FlinkHashJoinExample {
public static void main(String[] args) throws Exception {
ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
// 生成第一个数据集
DataSet<Tuple2<Integer, String>> data1 = env.fromElements(
new Tuple2<>(1, "A"),
new Tuple2<>(2, "B"),
new Tuple2<>(3, "C")
);
// 生成第二个数据集
DataSet<Tuple2<Integer, String>> data2 = env.fromElements(
new Tuple2<>(1, "X"),
new Tuple2<>(2, "Y"),
new Tuple2<>(4, "Z")
);
// 按照第一个数据集的 key 进行 hash join
JoinOperator.DefaultJoin<Tuple2<Integer, String>, Tuple2<Integer, String>> result = data1
.join(data2)
.where(new KeySelector<Tuple2<Integer, String>, Integer>() {
@Override
public Integer getKey(Tuple2<Integer, String> tuple) throws Exception {
return tuple.f0;
}
})
.equalTo(new KeySelector<Tuple2<Integer, String>, Integer>() {
@Override
public Integer getKey(Tuple2<Integer, String> tuple) throws Exception {
return tuple.f0;
}
});
result.print();
}
}
```
这个代码将两个 `Tuple` 类型的数据集通过 key 进行 join,然后将结果打印出来。您可以根据实际需求进行调整。