add java performance worker
diff --git a/tools/run_tests/performance/build_performance.sh b/tools/run_tests/performance/build_performance.sh
index 2c962cb..85769ab 100755
--- a/tools/run_tests/performance/build_performance.sh
+++ b/tools/run_tests/performance/build_performance.sh
@@ -45,8 +45,15 @@
 
 for language in $@
 do
-  if [ "$language" != "c++" ]
-  then
+  case "$language" in
+  "c++")
+    ;;  # C++ has already been built.
+  "java")
+    (cd ../grpc-java/ &&
+      ./gradlew -PskipCodegen=true :grpc-benchmarks:installDist)
+    ;;
+  *)
     tools/run_tests/run_tests.py -l $language -c $CONFIG --build_only -j 8
-  fi
+    ;;
+  esac
 done