From dba81e1dcdea1e8bd196c88d4810f9a04312acbf Mon Sep 17 00:00:00 2001
From: adesharatushar <tushar_adeshara@persistent.com>
Date: Thu, 29 Dec 2016 22:03:34 +0000
Subject: [PATCH] [SPARK-19003][DOCS] Add Java example in Spark Streaming
Guide, section Design Patterns for using foreachRDD
## What changes were proposed in this pull request?
Added missing Java example under section "Design Patterns for using foreachRDD". Now this section has examples in all 3 languages, improving consistency of documentation.
## How was this patch tested?
Manual.
Generated docs using command "SKIP_API=1 jekyll build" and verified generated HTML page manually.
The syntax of example has been tested for correctness using sample code on Java1.7 and Spark 2.2.0-SNAPSHOT.
Author: adesharatushar <tushar_adeshara@persistent.com>
Closes #16408 from adesharatushar/streaming-doc-fix.
---
docs/streaming-programming-guide.md | 72 +++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)
diff --git a/docs/streaming-programming-guide.md b/docs/streaming-programming-guide.md
index 1fcd198685..38b4f78177 100644
--- a/docs/streaming-programming-guide.md
+++ b/docs/streaming-programming-guide.md
@@ -1246,6 +1246,22 @@ dstream.foreachRDD { rdd =>
}
{% endhighlight %}
</div>
+<div data-lang="java" markdown="1">
+{% highlight java %}
+dstream.foreachRDD(new VoidFunction<JavaRDD<String>>() {
+ @Override
+ public void call(JavaRDD<String> rdd) {
+ final Connection connection = createNewConnection(); // executed at the driver
+ rdd.foreach(new VoidFunction<String>() {
+ @Override
+ public void call(String record) {
+ connection.send(record); // executed at the worker
+ }
+ });
+ }
+});
+{% endhighlight %}
+</div>
<div data-lang="python" markdown="1">
{% highlight python %}
def sendRecord(rdd):
@@ -1279,6 +1295,23 @@ dstream.foreachRDD { rdd =>
}
{% endhighlight %}
</div>
+<div data-lang="java" markdown="1">
+{% highlight java %}
+dstream.foreachRDD(new VoidFunction<JavaRDD<String>>() {
+ @Override
+ public void call(JavaRDD<String> rdd) {
+ rdd.foreach(new VoidFunction<String>() {
+ @Override
+ public void call(String record) {
+ Connection connection = createNewConnection();
+ connection.send(record);
+ connection.close();
+ }
+ });
+ }
+});
+{% endhighlight %}
+</div>
<div data-lang="python" markdown="1">
{% highlight python %}
def sendRecord(record):
@@ -1309,6 +1342,25 @@ dstream.foreachRDD { rdd =>
}
{% endhighlight %}
</div>
+<div data-lang="java" markdown="1">
+{% highlight java %}
+dstream.foreachRDD(new VoidFunction<JavaRDD<String>>() {
+ @Override
+ public void call(JavaRDD<String> rdd) {
+ rdd.foreachPartition(new VoidFunction<Iterator<String>>() {
+ @Override
+ public void call(Iterator<String> partitionOfRecords) {
+ Connection connection = createNewConnection();
+ while (partitionOfRecords.hasNext()) {
+ connection.send(partitionOfRecords.next());
+ }
+ connection.close();
+ }
+ });
+ }
+});
+{% endhighlight %}
+</div>
<div data-lang="python" markdown="1">
{% highlight python %}
def sendPartition(iter):
@@ -1342,6 +1394,26 @@ dstream.foreachRDD { rdd =>
{% endhighlight %}
</div>
+<div data-lang="java" markdown="1">
+{% highlight java %}
+dstream.foreachRDD(new VoidFunction<JavaRDD<String>>() {
+ @Override
+ public void call(JavaRDD<String> rdd) {
+ rdd.foreachPartition(new VoidFunction<Iterator<String>>() {
+ @Override
+ public void call(Iterator<String> partitionOfRecords) {
+ // ConnectionPool is a static, lazily initialized pool of connections
+ Connection connection = ConnectionPool.getConnection();
+ while (partitionOfRecords.hasNext()) {
+ connection.send(partitionOfRecords.next());
+ }
+ ConnectionPool.returnConnection(connection); // return to the pool for future reuse
+ }
+ });
+ }
+});
+{% endhighlight %}
+</div>
<div data-lang="python" markdown="1">
{% highlight python %}
def sendPartition(iter):
--
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