diff --git a/cpc/test/CMakeLists.txt b/cpc/test/CMakeLists.txt
index 2d3af9bb..645ce12f 100644
--- a/cpc/test/CMakeLists.txt
+++ b/cpc/test/CMakeLists.txt
@@ -49,3 +49,10 @@ target_sources(cpc_test
     cpc_sketch_deserialize_from_java_test.cpp
 )
 endif()
+
+if (GENERATE)
+target_sources(cpc_test
+  PRIVATE
+    cpc_sketch_serialize_for_java.cpp
+)
+endif()
diff --git a/cpc/test/cpc_sketch_deserialize_from_java_test.cpp b/cpc/test/cpc_sketch_deserialize_from_java_test.cpp
index deaff5e1..70027e37 100644
--- a/cpc/test/cpc_sketch_deserialize_from_java_test.cpp
+++ b/cpc/test/cpc_sketch_deserialize_from_java_test.cpp
@@ -39,4 +39,22 @@ TEST_CASE("cpc sketch", "[serde_compat]") {
   }
 }
 
+TEST_CASE("cpc sketch negative one", "[serde_compat]") {
+  std::ifstream is;
+  is.exceptions(std::ios::failbit | std::ios::badbit);
+  is.open(testBinaryInputPath + "cpc_negative_one_java.sk", std::ios::binary);
+  auto sketch = cpc_sketch::deserialize(is);
+  REQUIRE_FALSE(sketch.is_empty());
+  REQUIRE(sketch.get_estimate() == Approx(1).margin(0.01));
+  sketch.update((uint64_t) -1);
+  sketch.update((int64_t) -1);
+  sketch.update((uint32_t) -1);
+  sketch.update((int32_t) -1);
+  sketch.update((uint16_t) -1);
+  sketch.update((int16_t) -1);
+  sketch.update((uint8_t) -1);
+  sketch.update((int8_t) -1);
+  REQUIRE(sketch.get_estimate() == Approx(1).margin(0.01));
+}
+
 } /* namespace datasketches */
diff --git a/cpc/test/cpc_sketch_serialize_for_java.cpp b/cpc/test/cpc_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..d46fa047
--- /dev/null
+++ b/cpc/test/cpc_sketch_serialize_for_java.cpp
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <cpc_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("cpc sketch generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 100, 200, 2000, 20000};
+  for (const unsigned n: n_arr) {
+    cpc_sketch sketch;
+    for (unsigned i = 1; i <= n; ++i) sketch.update(i);
+    REQUIRE(sketch.is_empty() == (n == 0));
+    REQUIRE(sketch.get_estimate() == Approx(n).margin(n * 0.02));
+    std::ofstream os("cpc_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+} /* namespace datasketches */
diff --git a/cpc/test/cpc_sketch_test.cpp b/cpc/test/cpc_sketch_test.cpp
index f45cbc15..fd9bcf37 100644
--- a/cpc/test/cpc_sketch_test.cpp
+++ b/cpc/test/cpc_sketch_test.cpp
@@ -88,9 +88,6 @@ TEST_CASE("cpc sketch: serialize deserialize empty", "[cpc_sketch]") {
   REQUIRE(deserialized.is_empty() == sketch.is_empty());
   REQUIRE(deserialized.get_estimate() == sketch.get_estimate());
   REQUIRE(deserialized.validate());
-
-  std::ofstream os("cpc-empty.bin");
-  sketch.serialize(os);
 }
 
 TEST_CASE("cpc sketch: serialize deserialize sparse", "[cpc_sketch]") {
@@ -108,9 +105,6 @@ TEST_CASE("cpc sketch: serialize deserialize sparse", "[cpc_sketch]") {
   for (int i = 0; i < n; i++) deserialized.update(i);
   REQUIRE(deserialized.get_estimate() == sketch.get_estimate());
   REQUIRE(deserialized.validate());
-
-  std::ofstream os("cpc-sparse.bin");
-  sketch.serialize(os);
 }
 
 TEST_CASE("cpc sketch: serialize deserialize hybrid", "[cpc_sketch]") {
@@ -128,9 +122,6 @@ TEST_CASE("cpc sketch: serialize deserialize hybrid", "[cpc_sketch]") {
   for (int i = 0; i < n; i++) deserialized.update(i);
   REQUIRE(deserialized.get_estimate() == sketch.get_estimate());
   REQUIRE(deserialized.validate());
-
-  std::ofstream os("cpc-hybrid.bin");
-  sketch.serialize(os);
 }
 
 TEST_CASE("cpc sketch: serialize deserialize pinned", "[cpc_sketch]") {
@@ -148,9 +139,6 @@ TEST_CASE("cpc sketch: serialize deserialize pinned", "[cpc_sketch]") {
   for (int i = 0; i < n; i++) deserialized.update(i);
   REQUIRE(deserialized.get_estimate() == sketch.get_estimate());
   REQUIRE(deserialized.validate());
-
-  std::ofstream os("cpc-pinned.bin");
-  sketch.serialize(os);
 }
 
 TEST_CASE("cpc sketch: serialize deserialize sliding", "[cpc_sketch]") {
@@ -168,9 +156,6 @@ TEST_CASE("cpc sketch: serialize deserialize sliding", "[cpc_sketch]") {
   for (int i = 0; i < n; i++) deserialized.update(i);
   REQUIRE(deserialized.get_estimate() == sketch.get_estimate());
   REQUIRE(deserialized.validate());
-
-  std::ofstream os("cpc-sliding.bin");
-  sketch.serialize(os);
 }
 
 TEST_CASE("cpc sketch: serializing deserialize sliding large", "[cpc_sketch]") {
@@ -188,9 +173,6 @@ TEST_CASE("cpc sketch: serializing deserialize sliding large", "[cpc_sketch]") {
   for (int i = 0; i < n; i++) deserialized.update(i);
   REQUIRE(deserialized.get_estimate() == sketch.get_estimate());
   REQUIRE(deserialized.validate());
-
-  std::ofstream os("cpc-sliding-large.bin");
-  sketch.serialize(os);
 }
 
 TEST_CASE("cpc sketch: serialize deserialize empty, bytes", "[cpc_sketch]") {
@@ -201,9 +183,6 @@ TEST_CASE("cpc sketch: serialize deserialize empty, bytes", "[cpc_sketch]") {
   REQUIRE(deserialized.get_estimate() == sketch.get_estimate());
   REQUIRE(deserialized.validate());
   REQUIRE_THROWS_AS(cpc_sketch::deserialize(bytes.data(), bytes.size() - 1), std::out_of_range);
-
-  std::ofstream os("cpc-empty.bin");
-  sketch.serialize(os);
 }
 
 TEST_CASE("cpc sketch: serialize deserialize sparse, bytes", "[cpc_sketch]") {
@@ -261,8 +240,6 @@ TEST_CASE("cpc sketch: serialize deserialize pinned, bytes", "[cpc_sketch]") {
   for (int i = 0; i < n; i++) deserialized.update(i);
   REQUIRE(deserialized.get_estimate() == sketch.get_estimate());
   REQUIRE(deserialized.validate());
-
-  std::cout << sketch.to_string();
 }
 
 TEST_CASE("cpc sketch: serialize deserialize sliding, bytes", "[cpc_sketch]") {
@@ -380,8 +357,6 @@ TEST_CASE("cpc sketch: update int equivalence", "[cpc_sketch]") {
   sketch.update((uint8_t) -1);
   sketch.update((int8_t) -1);
   REQUIRE(sketch.get_estimate() == Approx(1).margin(RELATIVE_ERROR_FOR_LG_K_11));
-  std::ofstream os("cpc-negative-one.bin"); // to compare with Java
-  sketch.serialize(os);
 }
 
 TEST_CASE("cpc sketch: update float equivalence", "[cpc_sketch]") {
diff --git a/fi/test/CMakeLists.txt b/fi/test/CMakeLists.txt
index fc8780d2..0279b03f 100644
--- a/fi/test/CMakeLists.txt
+++ b/fi/test/CMakeLists.txt
@@ -48,3 +48,10 @@ target_sources(fi_test
    frequent_items_sketch_deserialize_from_java_test.cpp
 )
 endif()
+
+if (GENERATE)
+target_sources(fi_test
+  PRIVATE
+   frequent_items_sketch_serialize_for_java.cpp
+)
+endif()
diff --git a/fi/test/frequent_items_sketch_serialize_for_java.cpp b/fi/test/frequent_items_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..4b99b309
--- /dev/null
+++ b/fi/test/frequent_items_sketch_serialize_for_java.cpp
@@ -0,0 +1,83 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <frequent_items_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("frequent longs sketch generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    frequent_items_sketch<long> sketch(6);
+    for (unsigned i = 1; i <= n; ++i) sketch.update(i);
+    REQUIRE(sketch.is_empty() == (n == 0));
+    if (n > 10) {
+      REQUIRE(sketch.get_maximum_error() > 0);
+    } else {
+      REQUIRE(sketch.get_maximum_error() == 0);
+    }
+    REQUIRE(sketch.get_total_weight() == n);
+    std::ofstream os("frequent_long_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+TEST_CASE("frequent strings sketch generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    frequent_items_sketch<std::string> sketch(6);
+    for (unsigned i = 1; i <= n; ++i) sketch.update(std::to_string(i));
+    REQUIRE(sketch.is_empty() == (n == 0));
+    if (n > 10) {
+      REQUIRE(sketch.get_maximum_error() > 0);
+    } else {
+      REQUIRE(sketch.get_maximum_error() == 0);
+    }
+    REQUIRE(sketch.get_total_weight() == n);
+    std::ofstream os("frequent_string_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+TEST_CASE("frequent strings sketch ascii", "[serialize_for_java]") {
+  frequent_items_sketch<std::string> sketch(6);
+  sketch.update("aaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 1);
+  sketch.update("bbbbbbbbbbbbbbbbbbbbbbbbbbbbb", 2);
+  sketch.update("ccccccccccccccccccccccccccccc", 3);
+  sketch.update("ddddddddddddddddddddddddddddd", 4);
+  std::ofstream os("frequent_string_ascii_cpp.sk", std::ios::binary);
+  sketch.serialize(os);
+}
+
+TEST_CASE("frequent strings sketch utf8", "[serialize_for_java]") {
+  frequent_items_sketch<std::string> sketch(6);
+  sketch.update("абвгд", 1);
+  sketch.update("еёжзи", 2);
+  sketch.update("йклмн", 3);
+  sketch.update("опрст", 4);
+  sketch.update("уфхцч", 5);
+  sketch.update("шщъыь", 6);
+  sketch.update("эюя", 7);
+  std::ofstream os("frequent_string_utf8_cpp.sk", std::ios::binary);
+  sketch.serialize(os);
+}
+
+} /* namespace datasketches */
diff --git a/hll/test/CMakeLists.txt b/hll/test/CMakeLists.txt
index 202560fc..efdc5215 100644
--- a/hll/test/CMakeLists.txt
+++ b/hll/test/CMakeLists.txt
@@ -55,3 +55,10 @@ target_sources(hll_test
    hll_sketch_deserialize_from_java_test.cpp
 )
 endif()
+
+if (GENERATE)
+target_sources(hll_test
+  PRIVATE
+   hll_sketch_serialize_for_java.cpp
+)
+endif()
diff --git a/hll/test/hll_sketch_serialize_for_java.cpp b/hll/test/hll_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..e329c58f
--- /dev/null
+++ b/hll/test/hll_sketch_serialize_for_java.cpp
@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <hll.hpp>
+
+namespace datasketches {
+
+TEST_CASE("hll sketch generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    hll_sketch hll4(12, HLL_4);
+    hll_sketch hll6(12, HLL_6);
+    hll_sketch hll8(12, HLL_8);
+    for (unsigned i = 0; i < n; ++i) {
+      hll4.update(i);
+      hll6.update(i);
+      hll8.update(i);
+    }
+    {
+      std::ofstream os("hll4_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+      hll4.serialize_compact(os);
+    }
+    {
+      std::ofstream os("hll6_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+      hll6.serialize_compact(os);
+    }
+    {
+      std::ofstream os("hll8_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+      hll8.serialize_compact(os);
+    }
+  }
+}
+
+} /* namespace datasketches */
diff --git a/kll/test/CMakeLists.txt b/kll/test/CMakeLists.txt
index 17018531..1e6f6f9f 100644
--- a/kll/test/CMakeLists.txt
+++ b/kll/test/CMakeLists.txt
@@ -49,3 +49,10 @@ target_sources(kll_test
     kll_sketch_deserialize_from_java_test.cpp
 )
 endif()
+
+if (GENERATE)
+target_sources(kll_test
+  PRIVATE
+    kll_sketch_serialize_for_java.cpp
+)
+endif()
diff --git a/kll/test/kll_sketch_serialize_for_java.cpp b/kll/test/kll_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..00b8913d
--- /dev/null
+++ b/kll/test/kll_sketch_serialize_for_java.cpp
@@ -0,0 +1,62 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <kll_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("kll sketch float generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    kll_sketch<float> sketch;
+    for (unsigned i = 1; i <= n; ++i) sketch.update(i);
+    std::ofstream os("kll_float_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+TEST_CASE("kll sketch double generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    kll_sketch<double> sketch;
+    for (unsigned i = 1; i <= n; ++i) sketch.update(i);
+    std::ofstream os("kll_double_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+struct compare_as_number {
+  bool operator()(const std::string& a, const std::string& b) const {
+    return std::stoi(a) < std::stoi(b);
+  }
+};
+
+TEST_CASE("kll sketch string generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    kll_sketch<std::string, compare_as_number> sketch;
+    for (unsigned i = 1; i <= n; ++i) sketch.update(std::to_string(i));
+    std::ofstream os("kll_string_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+} /* namespace datasketches */
diff --git a/quantiles/test/CMakeLists.txt b/quantiles/test/CMakeLists.txt
index 1831900d..dd999b8c 100644
--- a/quantiles/test/CMakeLists.txt
+++ b/quantiles/test/CMakeLists.txt
@@ -48,3 +48,10 @@ target_sources(quantiles_test
     quantiles_sketch_deserialize_from_java_test.cpp
 )
 endif()
+
+if (GENERATE)
+target_sources(quantiles_test
+  PRIVATE
+    quantiles_sketch_serialize_for_java.cpp
+)
+endif()
diff --git a/quantiles/test/quantiles_sketch_serialize_for_java.cpp b/quantiles/test/quantiles_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..d762d7c4
--- /dev/null
+++ b/quantiles/test/quantiles_sketch_serialize_for_java.cpp
@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <quantiles_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("quantiles sketch double generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    quantiles_sketch<double> sketch;
+    for (unsigned i = 1; i <= n; ++i) sketch.update(i);
+    std::ofstream os("quantiles_double_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+struct compare_as_number {
+  bool operator()(const std::string& a, const std::string& b) const {
+    return std::stoi(a) < std::stoi(b);
+  }
+};
+
+TEST_CASE("quantiles sketch string generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    quantiles_sketch<std::string, compare_as_number> sketch;
+    for (unsigned i = 1; i <= n; ++i) sketch.update(std::to_string(i));
+    std::ofstream os("quantiles_string_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+} /* namespace datasketches */
diff --git a/req/test/CMakeLists.txt b/req/test/CMakeLists.txt
index 72fb39b2..8ebaadb0 100755
--- a/req/test/CMakeLists.txt
+++ b/req/test/CMakeLists.txt
@@ -47,3 +47,10 @@ target_sources(req_test
     req_sketch_deserialize_from_java_test.cpp
 )
 endif()
+
+if (GENERATE)
+target_sources(req_test
+  PRIVATE
+    req_sketch_serialize_for_java.cpp
+)
+endif()
diff --git a/req/test/req_sketch_serialize_for_java.cpp b/req/test/req_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..d244cb70
--- /dev/null
+++ b/req/test/req_sketch_serialize_for_java.cpp
@@ -0,0 +1,36 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <req_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("req sketch float generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    req_sketch<float> sketch(12);
+    for (unsigned i = 1; i <= n; ++i) sketch.update(i);
+    std::ofstream os("req_float_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+} /* namespace datasketches */
diff --git a/sampling/test/CMakeLists.txt b/sampling/test/CMakeLists.txt
index f62a1442..8264f9c6 100644
--- a/sampling/test/CMakeLists.txt
+++ b/sampling/test/CMakeLists.txt
@@ -49,3 +49,11 @@ target_sources(sampling_test
    var_opt_union_deserialize_from_java_test.cpp
 )
 endif()
+
+if (GENERATE)
+target_sources(sampling_test
+  PRIVATE
+   var_opt_sketch_serialize_for_java.cpp
+   var_opt_union_serialize_for_java.cpp
+)
+endif()
diff --git a/sampling/test/var_opt_sketch_serialize_for_java.cpp b/sampling/test/var_opt_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..225b4db9
--- /dev/null
+++ b/sampling/test/var_opt_sketch_serialize_for_java.cpp
@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <var_opt_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("varopt sketch long generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    var_opt_sketch<long> sketch(32);
+    for (unsigned i = 1; i <= n; ++i) sketch.update(i);
+    std::ofstream os("varopt_sketch_long_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.serialize(os);
+  }
+}
+
+TEST_CASE("varopt sketch string exact", "[serialize_for_java]") {
+  var_opt_sketch<std::string> sketch(1024);
+  for (unsigned i = 1; i <= 200; ++i) sketch.update(std::to_string(i), 1000.0 / i);
+  std::ofstream os("varopt_sketch_string_exact_cpp.sk", std::ios::binary);
+  sketch.serialize(os);
+}
+
+TEST_CASE("varopt sketch long sampling", "[serialize_for_java]") {
+  var_opt_sketch<long> sketch(1024);
+  for (unsigned i = 0; i < 2000; ++i) sketch.update(i);
+  // negative heavy items to allow a simple predicate to filter
+  sketch.update(-1L, 100000.0);
+  sketch.update(-2L, 110000.0);
+  sketch.update(-3L, 120000.0);
+  std::ofstream os("varopt_sketch_long_sampling_cpp.sk", std::ios::binary);
+  sketch.serialize(os);
+}
+
+} /* namespace datasketches */
diff --git a/sampling/test/var_opt_union_serialize_for_java.cpp b/sampling/test/var_opt_union_serialize_for_java.cpp
new file mode 100644
index 00000000..e45fc1c4
--- /dev/null
+++ b/sampling/test/var_opt_union_serialize_for_java.cpp
@@ -0,0 +1,56 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <var_opt_union.hpp>
+
+namespace datasketches {
+
+TEST_CASE("var opt union double sampling", "[serialize_for_java]") {
+  const unsigned k_small = 16;
+  const unsigned k_max = 128;
+  const unsigned n1 = 32;
+  const unsigned n2 = 64;
+
+  // small k sketch, but sampling
+  var_opt_sketch<double> sketch1(k_small);
+  for (unsigned i = 0; i < n1; ++i) sketch1.update(i);
+  // negative heavy item to allow a simple predicate to filter
+  sketch1.update(-1, n1 * n1);
+
+  // another one, but different n to get a different per-item weight
+  var_opt_sketch<double> sketch2(k_small);
+  for (unsigned i = 0; i < n2; ++i) sketch2.update(i);
+
+  var_opt_union<double> u(k_max);
+  u.update(sketch1);
+  u.update(sketch2);
+
+  // must reduce k in the process
+  auto result = u.get_result();
+  REQUIRE(result.get_k() < k_max);
+  REQUIRE(result.get_k() >= k_small);
+  REQUIRE(result.get_n() == 97);
+
+  std::ofstream os("varopt_union_double_sampling_cpp.sk", std::ios::binary);
+  u.serialize(os);
+}
+
+} /* namespace datasketches */
diff --git a/theta/test/CMakeLists.txt b/theta/test/CMakeLists.txt
index 48998310..24b22fe1 100644
--- a/theta/test/CMakeLists.txt
+++ b/theta/test/CMakeLists.txt
@@ -52,3 +52,10 @@ target_sources(theta_test
     theta_sketch_deserialize_from_java_test.cpp
 )
 endif()
+
+if (GENERATE)
+target_sources(theta_test
+  PRIVATE
+    theta_sketch_serialize_for_java.cpp
+)
+endif()
diff --git a/theta/test/theta_sketch_serialize_for_java.cpp b/theta/test/theta_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..487553f0
--- /dev/null
+++ b/theta/test/theta_sketch_serialize_for_java.cpp
@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <theta_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("theta sketch generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    auto sketch = update_theta_sketch::builder().build();
+    for (unsigned i = 0; i < n; ++i) sketch.update(i);
+    REQUIRE(sketch.is_empty() == (n == 0));
+    REQUIRE(sketch.get_estimate() == Approx(n).margin(n * 0.03));
+    std::ofstream os("theta_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.compact().serialize(os);
+  }
+}
+
+TEST_CASE("theta sketch generate compressed", "[serialize_for_java]") {
+  const unsigned n_arr[] = {10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    auto sketch = update_theta_sketch::builder().build();
+    for (unsigned i = 0; i < n; ++i) sketch.update(i);
+    REQUIRE_FALSE(sketch.is_empty());
+    REQUIRE(sketch.get_estimate() == Approx(n).margin(n * 0.03));
+    std::ofstream os("theta_compressed_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.compact().serialize(os);
+  }
+}
+
+TEST_CASE("theta sketch generate non-empty no entries", "[serialize_for_java]") {
+  auto sketch = update_theta_sketch::builder().set_p(0.01).build();
+  // here we rely on the fact that hash of 1 happens to be greater than 0.01 (when normalized)
+  // and therefore gets rejected
+  sketch.update(1);
+  REQUIRE_FALSE(sketch.is_empty());
+  REQUIRE(sketch.get_num_retained() == 0);
+  std::ofstream os("theta_non_empty_no_entries_cpp.sk", std::ios::binary);
+  sketch.compact().serialize(os);
+}
+
+} /* namespace datasketches */
diff --git a/tuple/test/CMakeLists.txt b/tuple/test/CMakeLists.txt
index 003c02ca..4ca6a503 100644
--- a/tuple/test/CMakeLists.txt
+++ b/tuple/test/CMakeLists.txt
@@ -51,5 +51,14 @@ if (SERDE_COMPAT)
 target_sources(tuple_test
   PRIVATE
     aod_sketch_deserialize_from_java_test.cpp
+    tuple_sketch_deserialize_from_java_test.cpp
+)
+endif()
+
+if (GENERATE)
+target_sources(tuple_test
+  PRIVATE
+    aod_sketch_serialize_for_java.cpp
+    tuple_sketch_serialize_for_java.cpp
 )
 endif()
diff --git a/tuple/test/aod_sketch_serialize_for_java.cpp b/tuple/test/aod_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..4ca978a3
--- /dev/null
+++ b/tuple/test/aod_sketch_serialize_for_java.cpp
@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <array_of_doubles_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("aod sketch generate one value", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    auto sketch = update_array_of_doubles_sketch::builder().build();
+    for (unsigned i = 0; i < n; ++i) sketch.update(i, std::vector<double>(1, i));
+    REQUIRE(sketch.is_empty() == (n == 0));
+    REQUIRE(sketch.get_estimate() == Approx(n).margin(n * 0.03));
+    std::ofstream os("aod_1_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.compact().serialize(os);
+  }
+}
+
+TEST_CASE("aod sketch generate three values", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    auto sketch = update_array_of_doubles_sketch::builder(3).build();
+    for (unsigned i = 0; i < n; ++i) sketch.update(i, std::vector<double>(3, i));
+    REQUIRE(sketch.is_empty() == (n == 0));
+    REQUIRE(sketch.get_estimate() == Approx(n).margin(n * 0.03));
+    std::ofstream os("aod_3_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.compact().serialize(os);
+  }
+}
+
+TEST_CASE("aod sketch generate non-empty no entries", "[serialize_for_java]") {
+  auto sketch = update_array_of_doubles_sketch::builder().set_p(0.01).build();
+  // here we rely on the fact that hash of 1 happens to be greater than 0.01 (when normalized)
+  // and therefore gets rejected
+  sketch.update(1, std::vector<double>({1}));
+  REQUIRE_FALSE(sketch.is_empty());
+  REQUIRE(sketch.get_num_retained() == 0);
+  std::ofstream os("aod_1_non_empty_no_entries_cpp.sk", std::ios::binary);
+  sketch.compact().serialize(os);
+}
+
+} /* namespace datasketches */
diff --git a/tuple/test/tuple_sketch_deserialize_from_java_test.cpp b/tuple/test/tuple_sketch_deserialize_from_java_test.cpp
new file mode 100644
index 00000000..408223f9
--- /dev/null
+++ b/tuple/test/tuple_sketch_deserialize_from_java_test.cpp
@@ -0,0 +1,47 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <tuple_sketch.hpp>
+
+namespace datasketches {
+
+// assume the binary sketches for this test have been generated by datasketches-java code
+// in the subdirectory called "java" in the root directory of this project
+static std::string testBinaryInputPath = std::string(TEST_BINARY_INPUT_PATH) + "../../java/";
+
+TEST_CASE("tuple sketch int", "[serde_compat]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    std::ifstream is;
+    is.exceptions(std::ios::failbit | std::ios::badbit);
+    is.open(testBinaryInputPath + "tuple_int_n" + std::to_string(n) + "_java.sk", std::ios::binary);
+    const auto sketch = compact_tuple_sketch<int>::deserialize(is);
+    REQUIRE(sketch.is_empty() == (n == 0));
+    REQUIRE(sketch.is_estimation_mode() == (n > 1000));
+    REQUIRE(sketch.get_estimate() == Approx(n).margin(n * 0.03));
+    for (const auto& entry: sketch) {
+      REQUIRE(entry.first < sketch.get_theta64());
+      REQUIRE(entry.second < static_cast<int>(n));
+    }
+  }
+}
+
+} /* namespace datasketches */
diff --git a/tuple/test/tuple_sketch_serialize_for_java.cpp b/tuple/test/tuple_sketch_serialize_for_java.cpp
new file mode 100644
index 00000000..6f2bf502
--- /dev/null
+++ b/tuple/test/tuple_sketch_serialize_for_java.cpp
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <catch2/catch.hpp>
+#include <fstream>
+#include <tuple_sketch.hpp>
+
+namespace datasketches {
+
+TEST_CASE("tuple sketch int generate", "[serialize_for_java]") {
+  const unsigned n_arr[] = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
+  for (const unsigned n: n_arr) {
+    auto sketch = update_tuple_sketch<int>::builder().build();
+    for (unsigned i = 0; i < n; ++i) sketch.update(i, i);
+    REQUIRE(sketch.is_empty() == (n == 0));
+    REQUIRE(sketch.get_estimate() == Approx(n).margin(n * 0.03));
+    std::ofstream os("tuple_int_n" + std::to_string(n) + "_cpp.sk", std::ios::binary);
+    sketch.compact().serialize(os);
+  }
+}
+
+} /* namespace datasketches */