perf tunning

src/main/java/com/alibaba/fastjson/parser/JSONScanner.java

@@ -928,8 +928,8 @@ public final class JSONScanner implements JSONLexer {
             return stringDefaultValue();
         }
 
-        String strVal;
-        int start = index;
+        final String strVal;
+        final int start = index;
         for (;;) {
             ch = buf[index++];
             if (ch == '\"') {

vtune.sh

@@ -0,0 +1,2 @@
+export AMPLXE_EXPERIMENTAL=1
+/opt/intel/vtune_amplifier_xe/bin64/amplxe-cl -collect hotspots java -classpath target/classes/:target/test-classes/ com.alibaba.json.test.benchmark.BenchmarkMain