## What changes were proposed in this pull request?

This change modifies the implementation of DataFrameWriter.save such that it works with jdbc, and the call to jdbc merely delegates to save.

## How was this patch tested?

This was tested via unit tests in the JDBCWriteSuite, of which I added one new test to cover this scenario.

## Additional details

rxin This seems to have been most recently touched by you and was also commented on in the JIRA.

This contribution is my original work and I license the work to the project under the project's open source license.

Author: Justin Pihony <justin.pihony@gmail.com>
Author: Justin Pihony <justin.pihony@typesafe.com>

Closes #12601 from JustinPihony/jdbc_reconciliation.

Code is equivalent, but map comprehency is most of the time faster than a map.

Author: Gaetan Semet <gaetan@xeberon.net>

Closes #14863 from Stibbons/map_comprehension.

## What changes were proposed in this pull request?

We propose to fix the Encoder type in the Dataset example

## How was this patch tested?

The PR will be tested with the current unit test cases

Author: CodingCat <zhunansjtu@gmail.com>

Closes #14901 from CodingCat/SPARK-17347.

## What changes were proposed in this pull request?

Allow centering / mean scaling of sparse vectors in StandardScaler, if requested. This is for compatibility with `VectorAssembler` in common usages.

## How was this patch tested?

Jenkins tests, including new caes to reflect the new behavior.

Author: Sean Owen <sowen@cloudera.com>

Closes #14663 from srowen/SPARK-17001.

## What changes were proposed in this pull request?
As Spark 2.0.1 will be released soon (mentioned in the spark dev mailing list), besides the critical bugs, it's better to fix the code style errors before the release.

Before:
```
./dev/lint-java
Checkstyle checks failed at following occurrences:
[ERROR] src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java:[525] (sizes) LineLength: Line is longer than 100 characters (found 119).
[ERROR] src/main/java/org/apache/spark/examples/sql/streaming/JavaStructuredNetworkWordCount.java:[64] (sizes) LineLength: Line is longer than 100 characters (found 103).
```
After:
```
./dev/lint-java
Using `mvn` from path: /usr/local/bin/mvn
Checkstyle checks passed.
```
## How was this patch tested?
Manual.

Author: Weiqing Yang <yangweiqing001@gmail.com>

Closes #14768 from Sherry302/fixjavastyle.

## What changes were proposed in this pull request?

(Please fill in changes proposed in this fix)

For R SQL example, appname is "MyApp". While examples in scala, Java and python, the appName is "x Spark SQL basic example".

I made the R example consistent with other examples.

## How was this patch tested?

(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)

Manual test
(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Author: wm624@hotmail.com <wm624@hotmail.com>

Closes #14703 from wangmiao1981/example.

## What changes were proposed in this pull request?

Originally this PR was based on #14491 but I realised that fixing examples are more sensible rather than comments.

This PR fixes three things below:

 - Fix two wrong examples in `structured-streaming-programming-guide.md`. Loading via `read.load(..)` without `as` will be `Dataset<Row>` not `Dataset<String>` in Java.

- Fix indentation across `structured-streaming-programming-guide.md`. Python has 4 spaces and Scala and Java have double spaces. These are inconsistent across the examples.

- Fix `StructuredNetworkWordCountWindowed` and  `StructuredNetworkWordCount` in Java and Scala to initially load `DataFrame` and `Dataset<Row>` to be consistent with the comments and some examples in `structured-streaming-programming-guide.md` and to match Scala and Java to Python one (Python one loads it as `DataFrame` initially).

## How was this patch tested?

N/A

Closes https://github.com/apache/spark/pull/14491

Author: hyukjinkwon <gurwls223@gmail.com>
Author: Ganesh Chand <ganeshchand@Ganeshs-MacBook-Pro-2.local>

Closes #14564 from HyukjinKwon/SPARK-16886.

## What changes were proposed in this pull request?
This PR is to fix the minor Java linter errors as following:
[ERROR] src/main/java/org/apache/spark/sql/catalyst/expressions/VariableLengthRowBasedKeyValueBatch.java:[42,10] (modifier) RedundantModifier: Redundant 'final' modifier.
[ERROR] src/main/java/org/apache/spark/sql/catalyst/expressions/VariableLengthRowBasedKeyValueBatch.java:[97,10] (modifier) RedundantModifier: Redundant 'final' modifier.

## How was this patch tested?
Manual test.
dev/lint-java
Using `mvn` from path: /usr/local/bin/mvn
Checkstyle checks passed.

Author: Weiqing Yang <yangweiqing001@gmail.com>

Closes #14532 from Sherry302/master.

## What changes were proposed in this pull request?
Improve example outputs to better reflect the functionality that is being presented.  This mostly consisted of modifying what was printed at the end of the example, such as calling show() with truncate=False, but sometimes required minor tweaks in the example data to get relevant output.  Explicitly set parameters when they are used as part of the example.  Fixed Java examples that failed to run because of using old-style MLlib Vectors or problem with schema.  Synced examples between different APIs.

## How was this patch tested?
Ran each example for Scala, Python, and Java and made sure output was legible on a terminal of width 100.

Author: Bryan Cutler <cutlerb@gmail.com>

Closes #14308 from BryanCutler/ml-examples-improve-output-SPARK-16260.

## What changes were proposed in this pull request?

Modify java example which is also reflect in document.

## How was this patch tested?

run test cases.

Author: sandy <phalodi@gmail.com>

Closes #14436 from phalodi/SPARK-16816.

[SPARK-16558][EXAMPLES][MLLIB] examples/mllib/LDAExample should use MLVector instead of MLlib Vector

## What changes were proposed in this pull request?

mllib.LDAExample uses ML pipeline and MLlib LDA algorithm. The former transforms original data into MLVector format, while the latter uses MLlibVector format.

## How was this patch tested?

Test manually.

Author: Xusen Yin <yinxusen@gmail.com>

Closes #14212 from yinxusen/SPARK-16558.

## What changes were proposed in this pull request?

This PR makes various minor updates to examples of all language bindings to make sure they are consistent with each other. Some typos and missing parts (JDBC example in Scala/Java/Python) are also fixed.

## How was this patch tested?

Manually tested.

Author: Cheng Lian <lian@databricks.com>

Closes #14368 from liancheng/revise-examples.

## What changes were proposed in this pull request?
Some Java examples are using mllib.linalg.Vectors instead of ml.linalg.Vectors and causes an exception when run.  Also there are some Java examples that incorrectly specify data types in the schema, also causing an exception.

## How was this patch tested?
Ran corrected examples locally

Author: Bryan Cutler <cutlerb@gmail.com>

Closes #14405 from BryanCutler/java-examples-ml.Vectors-fix-SPARK-16800.

[SPARK-16694][CORE] Use for/foreach rather than map for Unit expressions whose side effects are required

## What changes were proposed in this pull request?

Use foreach/for instead of map where operation requires execution of body, not actually defining a transformation

## How was this patch tested?

Jenkins

Author: Sean Owen <sowen@cloudera.com>

Closes #14332 from srowen/SPARK-16694.

This PR is based on PR #14098 authored by wangmiao1981.

## What changes were proposed in this pull request?

This PR replaces the original Python Spark SQL example file with the following three files:

- `sql/basic.py`

  Demonstrates basic Spark SQL features.

- `sql/datasource.py`

  Demonstrates various Spark SQL data sources.

- `sql/hive.py`

  Demonstrates Spark SQL Hive interaction.

This PR also removes hard-coded Python example snippets in the SQL programming guide by extracting snippets from the above files using the `include_example` Liquid template tag.

## How was this patch tested?

Manually tested.

Author: wm624@hotmail.com <wm624@hotmail.com>
Author: Cheng Lian <lian@databricks.com>

Closes #14317 from liancheng/py-examples-update.

[SPARK-16535][BUILD] In pom.xml, remove groupId which is redundant definition and inherited from the parent

https://issues.apache.org/jira/browse/SPARK-16535

## What changes were proposed in this pull request?

When I scan through the pom.xml of sub projects, I found this warning as below and attached screenshot
```
Definition of groupId is redundant, because it's inherited from the parent
```
![screen shot 2016-07-13 at 3 13 11 pm](https://cloud.githubusercontent.com/assets/3925641/16823121/744f893e-4916-11e6-8a52-042f83b9db4e.png)

I've tried to remove some of the lines with groupId definition, and the build on my local machine is still ok.
```
<groupId>org.apache.spark</groupId>
```
As I just find now `<maven.version>3.3.9</maven.version>` is being used in Spark 2.x, and Maven-3 supports versionless parent elements: Maven 3 will remove the need to specify the parent version in sub modules. THIS is great (in Maven 3.1).

ref: http://stackoverflow.com/questions/3157240/maven-3-worth-it/3166762#3166762

## How was this patch tested?

I've tested by re-building the project, and build succeeded.

Author: Xin Ren <iamshrek@126.com>

Closes #14189 from keypointt/SPARK-16535.

## What changes were proposed in this pull request?

This PR fixes four java linter `LineLength` errors. Those are all `LineLength` errors, but we had better remove all java linter errors before release.

## How was this patch tested?

After pass the Jenkins, `./dev/lint-java`.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #14255 from dongjoon-hyun/minor_java_linter.

## What changes were proposed in this pull request?

This PR moves one and the last hard-coded Scala example snippet from the SQL programming guide into `SparkSqlExample.scala`. It also renames all Scala/Java example files so that all "Sql" in the file names are updated to "SQL".

## How was this patch tested?

Manually verified the generated HTML page.

Author: Cheng Lian <lian@databricks.com>

Closes #14245 from liancheng/minor-scala-example-update.

## What changes were proposed in this pull request?
The second arg in method `update()` is never used. So I delete it.

## How was this patch tested?
local run with `./bin/spark-submit examples/src/main/python/als.py`

Author: Zheng RuiFeng <ruifengz@foxmail.com>

Closes #14247 from zhengruifeng/als_refine.

## What changes were proposed in this pull request?

Fix code style from ad hoc review of RC4 doc

## How was this patch tested?

manual

shivaram

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #14250 from felixcheung/rdocs2rc4.

## What changes were proposed in this pull request?

Cleanup of examples, mostly from PySpark-ML to fix minor issues:  unused imports, style consistency, pipeline_example is a duplicate, use future print funciton, and a spelling error.

* The "Pipeline Example" is duplicated by "Simple Text Classification Pipeline" in Scala, Python, and Java.

* "Estimator Transformer Param Example" is duplicated by "Simple Params Example" in Scala, Python and Java

* Synced random_forest_classifier_example.py with Scala by adding IndexToString label converted

* Synced train_validation_split.py (in Scala ModelSelectionViaTrainValidationExample) by adjusting data split, adding grid for intercept.

* RegexTokenizer was doing nothing in tokenizer_example.py and JavaTokenizerExample.java, synced with Scala version

## How was this patch tested?
local tests and run modified examples

Author: Bryan Cutler <cutlerb@gmail.com>

Closes #14081 from BryanCutler/examples-cleanup-SPARK-16403.

## What changes were proposed in this pull request?

Minor example updates

## How was this patch tested?

manual

shivaram

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #14171 from felixcheung/rexample.

- Hard-coded Spark SQL sample snippets were moved into source files under examples sub-project.
- Removed the inconsistency between Scala and Java Spark SQL examples
- Scala and Java Spark SQL examples were updated

The work is still in progress. All involved examples were tested manually. An additional round of testing will be done after the code review.

![image](https://cloud.githubusercontent.com/assets/6235869/16710314/51851606-462a-11e6-9fbe-0818daef65e4.png)

Author: aokolnychyi <okolnychyyanton@gmail.com>

Closes #14119 from aokolnychyi/spark_16303.

## What changes were proposed in this pull request?

A structured streaming example with event time windowing.

## How was this patch tested?

Run locally

Author: James Thomas <jamesjoethomas@gmail.com>

Closes #13957 from jjthomas/current.

## What changes were proposed in this pull request?
* Update SparkR ML section to make them consistent with SparkR API docs.
* Since #13972 adds labelling support for the ```include_example``` Jekyll plugin, so that we can split the single ```ml.R``` example file into multiple line blocks with different labels, and include them in different algorithms/models in the generated HTML page.

## How was this patch tested?
Only docs update, manually check the generated docs.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #14011 from yanboliang/r-user-guide-update.

## What changes were proposed in this pull request?
After SPARK-16476 (committed earlier today as #14128), we can finally bump the version number.

## How was this patch tested?
N/A

Author: Reynold Xin <rxin@databricks.com>

Closes #14130 from rxin/SPARK-16477.

https://issues.apache.org/jira/browse/SPARK-16381

## What changes were proposed in this pull request?

Update SQL examples and programming guide for R language binding.

Here I just follow example https://github.com/apache/spark/compare/master...liancheng:example-snippet-extraction, created a separate R file to store all the example code.

## How was this patch tested?

Manual test on my local machine.
Screenshot as below:

![screen shot 2016-07-06 at 4 52 25 pm](https://cloud.githubusercontent.com/assets/3925641/16638180/13925a58-439a-11e6-8d57-8451a63dcae9.png)

Author: Xin Ren <iamshrek@126.com>

Closes #14082 from keypointt/SPARK-16381.

## What changes were proposed in this pull request?
1). Remove unused import in Scala example;

2). Move spark session import outside example off;

3). Change parameter setting the same as Scala;

4). Change comment to be consistent;

5). Make sure that Scala and python using the same data set;

I did one pass and fixed the above issues. There are missing examples in python, which might be added later.

TODO: For some examples, there are comments on how to run examples; But there are many missing. We can add them later.

## How was this patch tested?

(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)

Manually test them

Author: wm624@hotmail.com <wm624@hotmail.com>

Closes #14021 from wangmiao1981/ann.

[SPARK-16345][DOCUMENTATION][EXAMPLES][GRAPHX] Extract graphx programming guide example snippets from source files instead of hard code them

## What changes were proposed in this pull request?

I extract 6 example programs from GraphX programming guide and replace them with
`include_example` label.

The 6 example programs are:
- AggregateMessagesExample.scala
- SSSPExample.scala
- TriangleCountingExample.scala
- ConnectedComponentsExample.scala
- ComprehensiveExample.scala
- PageRankExample.scala

All the example code can run using
`bin/run-example graphx.EXAMPLE_NAME`

## How was this patch tested?

Manual.

Author: WeichenXu <WeichenXu123@outlook.com>

Closes #14015 from WeichenXu123/graphx_example_plugin.

## What changes were proposed in this pull request?

This PR adds labelling support for the `include_example` Jekyll plugin, so that we may split a single source file into multiple line blocks with different labels, and include them in multiple code snippets in the generated HTML page.

## How was this patch tested?

Manually tested.

<img width="923" alt="screenshot at jun 29 19-53-21" src="https://cloud.githubusercontent.com/assets/230655/16451099/66a76db2-3e33-11e6-84fb-63104c2f0688.png">

Author: Cheng Lian <lian@databricks.com>

Closes #13972 from liancheng/include-example-with-labels.

## What changes were proposed in this pull request?

Some appNames in ML examples are incorrect, mostly in PySpark but one in Scala.  This corrects the names.

## How was this patch tested?
Style, local tests

Author: Bryan Cutler <cutlerb@gmail.com>

Closes #13949 from BryanCutler/pyspark-example-appNames-fix-SPARK-16261.

## What changes were proposed in this pull request?

Network word count example for structured streaming

## How was this patch tested?

Run locally

Author: James Thomas <jamesjoethomas@gmail.com>
Author: James Thomas <jamesthomas@Jamess-MacBook-Pro.local>

Closes #13816 from jjthomas/master.

## What changes were proposed in this pull request?
Need to convert ML Vectors to the old MLlib style before doing Statistics.colStats operations on the DataFrame

## How was this patch tested?
Ran example, local tests

Author: Bryan Cutler <cutlerb@gmail.com>

Closes #13928 from BryanCutler/pyspark-ml-example-vector-conv-SPARK-16231.

## What changes were proposed in this pull request?

reduce the denominator of SparkPi by 1

## How was this patch tested?

  integration tests

Author: 杨浩 <yanghaogn@163.com>

Closes #13910 from yanghaogn/patch-1.

## What changes were proposed in this pull request?

Made changes to HashingTF,QuantileVectorizer and CountVectorizer

Author: GayathriMurali <gayathri.m@intel.com>

Closes #13745 from GayathriMurali/SPARK-15997.

## What changes were proposed in this pull request?

roxygen2 doc, programming guide, example updates

## How was this patch tested?

manual checks
shivaram

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #13751 from felixcheung/rsparksessiondoc.

## What changes were proposed in this pull request?

Make user guide changes to SparkR documentation for all changes that happened in 2.0 to Machine Learning APIs

Author: GayathriMurali <gayathri.m@intel.com>

Closes #13285 from GayathriMurali/SPARK-15129.

## What changes were proposed in this pull request?

add ml doc for ml isotonic regression
add scala example for ml isotonic regression
add java example for ml isotonic regression
add python example for ml isotonic regression

modify scala example for mllib isotonic regression
modify java example for mllib isotonic regression
modify python example for mllib isotonic regression

add data/mllib/sample_isotonic_regression_libsvm_data.txt
delete data/mllib/sample_isotonic_regression_data.txt
## How was this patch tested?

N/A

Author: WeichenXu <WeichenXu123@outlook.com>

Closes #13381 from WeichenXu123/add_isotonic_regression_doc.

## What changes were proposed in this pull request?

Currently, R examples(`dataframe.R` and `data-manipulation.R`) fail like the following. We had better update them before releasing 2.0 RC. This PR updates them to use up-to-date APIs.

```bash
$ bin/spark-submit examples/src/main/r/dataframe.R
...
Warning message:
'createDataFrame(sqlContext...)' is deprecated.
Use 'createDataFrame(data, schema = NULL, samplingRatio = 1.0)' instead.
See help("Deprecated")
...
Warning message:
'read.json(sqlContext...)' is deprecated.
Use 'read.json(path)' instead.
See help("Deprecated")
...
Error: could not find function "registerTempTable"
Execution halted
```

## How was this patch tested?

Manual.
```
curl -LO http://s3-us-west-2.amazonaws.com/sparkr-data/flights.csv
bin/spark-submit examples/src/main/r/dataframe.R
bin/spark-submit examples/src/main/r/data-manipulation.R flights.csv
```

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #13714 from dongjoon-hyun/SPARK-15996.

## What changes were proposed in this pull request?

We want to maintain API compatibility for DataFrameReader.text, and will introduce a new API called DataFrameReader.textFile which returns Dataset[String].

affected PRs:
https://github.com/apache/spark/pull/11731
https://github.com/apache/spark/pull/13104
https://github.com/apache/spark/pull/13184

## How was this patch tested?

N/A

Author: Wenchen Fan <wenchen@databricks.com>

Closes #13604 from cloud-fan/revert.