[SPARK-16816] Modify java example which is also reflect in documentation exmaple

[phalodi]

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.

[phalodi]

@srowen @rxin Hey guyss i make changes as you suggested but yeah it not exactly what you suggested, i change in example which is also reflect in documentation, so please review it and give give your comments i will change them if you guyss think its not look good.

Changes which i made

In currently spark 2.0 example for Json Dataset

In previous version example is as follows.

So i make 2.0 example also same as previous version while user read this, he/she can also know how to create JavaSparkContext by spark session.

[srowen]

OK, it doesn't hurt. OK to merge if this seems to help your case.

[phalodi]

@srowen Yeah i think its look better, complete the example like in earlier versions and also indirectly show how to works with java spark context while we have spark session.

[srowen]

Jenkins test this please

[SparkQA]

Test build #63127 has finished for PR 14436 at commit 3461517.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[srowen]

Merged to master