[SPARK-19550][BUILD][CORE][WIP] Remove Java 7 support

- Move external/java8-tests tests into core, streaming, sql and remove
- Remove MaxPermGen and related options
- Fix some reflection / TODOs around Java 8+ methods
- Update doc references to 1.7/1.8 differences
- Remove Java 7/8 related build profiles
- Update some plugins for better Java 8 compatibility
- Fix a few Java-related warnings

For the future:

- Update Java 8 examples to fully use Java 8
- Update Java tests to use lambdas for simplicity
- Update Java internal implementations to use lambdas

## How was this patch tested?

Existing tests

Author: Sean Owen <sowen@cloudera.com>

Closes #16871 from srowen/SPARK-19493.

1 files changed, 2 insertions, 7 deletions

diff --git a/docs/quick-start.md b/docs/quick-start.md
index 0836c602fe..04ac278762 100644
--- a/docs/quick-start.md
+++ b/docs/quick-start.md
@@ -320,13 +320,8 @@ public class SimpleApp {
     JavaSparkContext sc = new JavaSparkContext(conf);
     JavaRDD<String> logData = sc.textFile(logFile).cache();
 
-    long numAs = logData.filter(new Function<String, Boolean>() {
-      public Boolean call(String s) { return s.contains("a"); }
-    }).count();
-
-    long numBs = logData.filter(new Function<String, Boolean>() {
-      public Boolean call(String s) { return s.contains("b"); }
-    }).count();
+    long numAs = logData.filter(s -> s.contains("a")).count();
+    long numBs = logData.filter(s -> s.contains("b")).count();
 
     System.out.println("Lines with a: " + numAs + ", lines with b: " + numBs);