Merge some java gen fixes from Johan Oskarsson

Summary: Making Isset inner classes static because they don't need to reference their owner, and killing some unused variables.

Reviewed By: dreiss


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665244 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/compiler/cpp/src/generate/t_java_generator.cc b/compiler/cpp/src/generate/t_java_generator.cc
index 90b9328..f82d930 100644
--- a/compiler/cpp/src/generate/t_java_generator.cc
+++ b/compiler/cpp/src/generate/t_java_generator.cc
@@ -380,7 +380,7 @@
     out <<
       endl <<
       indent() << "public final Isset __isset = new Isset();" << endl <<
-      indent() << "public final class Isset {" << endl;
+      indent() << "public static final class Isset {" << endl;
     indent_up();
       for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
         indent(out) <<
@@ -461,10 +461,10 @@
   const vector<t_field*>& fields = tstruct->get_members();
   vector<t_field*>::const_iterator f_iter;
 
-  // Declare stack tmp variables
+  // Declare stack tmp variables and read struct header
   out <<
     indent() << "TField field;" << endl <<
-    indent() << "TStruct struct = iprot.readStructBegin();" << endl;
+    indent() << "iprot.readStructBegin();" << endl;
   
   // Loop over reading in fields
   indent(out) <<
@@ -550,11 +550,12 @@
   const vector<t_field*>& fields = tstruct->get_members();
   vector<t_field*>::const_iterator f_iter;
 
-  out <<
-    indent() << "TStruct struct = new TStruct(\"" << name << "\");" << endl <<
-    indent() << "TField field = new TField();" << endl <<
-    indent() << "oprot.writeStructBegin(struct);" << endl;
+  indent(out) << "TStruct struct = new TStruct(\"" << name << "\");" << endl;
+  indent(out) << "oprot.writeStructBegin(struct);" << endl;
 
+  if (!fields.empty()) {
+    indent(out) << "TField field = new TField();" << endl;
+  }
   for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
     bool null_allowed = type_can_be_null((*f_iter)->get_type());
     if (null_allowed) {
@@ -610,11 +611,12 @@
   const vector<t_field*>& fields = tstruct->get_members();
   vector<t_field*>::const_iterator f_iter;
 
-  out <<
-    indent() << "TStruct struct = new TStruct(\"" << name << "\");" << endl <<
-    indent() << "TField field = new TField();" << endl <<
-    indent() << "oprot.writeStructBegin(struct);" << endl;
+  indent(out) << "TStruct struct = new TStruct(\"" << name << "\");" << endl;
+  indent(out) << "oprot.writeStructBegin(struct);" << endl;
 
+  if (!fields.empty()) {
+    indent(out) << "TField field = new TField();" << endl;
+  }
   bool first = true;
   for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
     if (first) {