diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/data/AbstractHashMessageTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/data/AbstractHashMessageTest.java
new file mode 100644
index 000000000..41e645d76
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/data/AbstractHashMessageTest.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.data;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class AbstractHashMessageTest {
+    public class NewMessage extends AbstractHashMessage {
+        public NewMessage() {
+            super("key");
+        }
+    }
+
+    @Test
+    public void testHash() {
+        NewMessage message = new NewMessage();
+        Assert.assertEquals("key".hashCode(), message.getHashCode());
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/DefinitionLoaderTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/DefinitionLoaderTest.java
new file mode 100644
index 000000000..a3c44cc0a
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/DefinitionLoaderTest.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.define;
+
+import java.util.Iterator;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class DefinitionLoaderTest {
+    @Test
+    public void testLoad() {
+        TestDefineFile define = new TestDefineFile();
+        DefinitionLoader<ServiceInterface> definitionLoader = new DefinitionLoader<>(ServiceInterface.class, define);
+        Iterator<ServiceInterface> iterator = definitionLoader.iterator();
+        if (iterator.hasNext()) {
+            ServiceInterface service = iterator.next();
+            Assert.assertTrue(service instanceof ServiceInterface);
+            Assert.assertTrue(service instanceof ServiceImpl);
+        }
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/ServiceImpl.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/ServiceImpl.java
new file mode 100644
index 000000000..8978b3cc7
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/ServiceImpl.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.define;
+
+/**
+ * @author wu-sheng
+ */
+public class ServiceImpl implements ServiceInterface {
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/ServiceInterface.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/ServiceInterface.java
new file mode 100644
index 000000000..d47d4dbe0
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/ServiceInterface.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.define;
+
+/**
+ * @author wu-sheng
+ */
+public interface ServiceInterface {
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/TestDefineFile.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/TestDefineFile.java
new file mode 100644
index 000000000..5206e8052
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/define/TestDefineFile.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.define;
+
+/**
+ * @author wu-sheng
+ */
+public class TestDefineFile extends DefinitionFile {
+    @Override protected String fileName() {
+        return "test_define.define";
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/BytesUtilsTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/BytesUtilsTest.java
new file mode 100644
index 000000000..9e0e11476
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/BytesUtilsTest.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class BytesUtilsTest {
+    @Test
+    public void testLong2Bytes() {
+        Assert.assertEquals(655390L, BytesUtils.bytes2Long(BytesUtils.long2Bytes(655390L)));
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/CollectionUtilsTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/CollectionUtilsTest.java
new file mode 100644
index 000000000..9b10c4eee
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/CollectionUtilsTest.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.util;
+
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class CollectionUtilsTest {
+    @Test
+    public void testList() {
+        List<String> list = new LinkedList<>();
+        Assert.assertTrue(CollectionUtils.isEmpty(list));
+        Assert.assertFalse(CollectionUtils.isNotEmpty(list));
+    }
+
+    @Test
+    public void testMap() {
+        Map<String, String> map = new HashMap<>();
+        Assert.assertTrue(CollectionUtils.isEmpty(map));
+        Assert.assertFalse(CollectionUtils.isNotEmpty(map));
+    }
+
+    @Test
+    public void testArray() {
+        String[] array = new String[] {"abc"};
+        Assert.assertTrue(CollectionUtils.isNotEmpty(array));
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ColumnNameUtilsTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ColumnNameUtilsTest.java
new file mode 100644
index 000000000..263724d0e
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ColumnNameUtilsTest.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class ColumnNameUtilsTest {
+    @Test
+    public void testRename() {
+        Assert.assertEquals("newAttributeNameFromColumnName",
+            ColumnNameUtils.INSTANCE.rename("new_attribute_name_from_column_name"));
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ObjectUtilsTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ObjectUtilsTest.java
new file mode 100644
index 000000000..374e586db
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ObjectUtilsTest.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class ObjectUtilsTest {
+    @Test
+    public void testNullObject() {
+        Object o = new Object();
+        Assert.assertTrue(ObjectUtils.isNotEmpty(o));
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ResourceUtilsTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ResourceUtilsTest.java
new file mode 100644
index 000000000..643542da8
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/ResourceUtilsTest.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.util;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.Reader;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class ResourceUtilsTest {
+    @Test
+    public void testGetResource() throws IOException {
+        Reader read = ResourceUtils.read("TestResourceFile.txt");
+        try {
+            BufferedReader reader = new BufferedReader(read);
+            String line1 = reader.readLine();
+            Assert.assertEquals("skywalking", line1);
+        } finally {
+            read.close();
+        }
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/StringUtilsTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/StringUtilsTest.java
new file mode 100644
index 000000000..31130a81b
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/StringUtilsTest.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class StringUtilsTest {
+    @Test
+    public void testEmptyString() {
+        Assert.assertTrue(StringUtils.isEmpty(null));
+        Assert.assertTrue(StringUtils.isEmpty(""));
+
+        Assert.assertTrue(StringUtils.isNotEmpty("abc"));
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/TimeBucketUtilsTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/TimeBucketUtilsTest.java
new file mode 100644
index 000000000..ffaf530ce
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/util/TimeBucketUtilsTest.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed 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.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+
+package org.skywalking.apm.collector.core.util;
+
+import java.util.TimeZone;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * @author wu-sheng
+ */
+public class TimeBucketUtilsTest {
+    @Before
+    public void setup() {
+        TimeZone.setDefault(TimeZone.getTimeZone("Asia/Shanghai"));
+    }
+
+    @After
+    public void teardown() {
+
+    }
+
+    @Test
+    public void testGetInfoFromATimestamp() {
+        long timeMillis = 1509521745220L;
+        Assert.assertArrayEquals(new long[] {
+            20171101153545L,
+            20171101153544L,
+            20171101153543L,
+            20171101153542L,
+            20171101153541L
+        }, TimeBucketUtils.INSTANCE.getFiveSecondTimeBuckets(TimeBucketUtils.INSTANCE.getSecondTimeBucket(timeMillis)));
+        Assert.assertEquals(20171101153545L, TimeBucketUtils.INSTANCE.getSecondTimeBucket(timeMillis));
+        Assert.assertEquals(201711011535L, TimeBucketUtils.INSTANCE.getMinuteTimeBucket(timeMillis));
+        Assert.assertEquals(201711011500L, TimeBucketUtils.INSTANCE.getHourTimeBucket(timeMillis));
+        Assert.assertEquals(201711010000L, TimeBucketUtils.INSTANCE.getDayTimeBucket(timeMillis));
+    }
+}
diff --git a/apm-collector/apm-collector-core/src/test/resources/META-INF/defines/test_define.define b/apm-collector/apm-collector-core/src/test/resources/META-INF/defines/test_define.define
new file mode 100644
index 000000000..d44e660dd
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/resources/META-INF/defines/test_define.define
@@ -0,0 +1 @@
+org.skywalking.apm.collector.core.define.ServiceImpl
\ No newline at end of file
diff --git a/apm-collector/apm-collector-core/src/test/resources/TestResourceFile.txt b/apm-collector/apm-collector-core/src/test/resources/TestResourceFile.txt
new file mode 100644
index 000000000..d967dd633
--- /dev/null
+++ b/apm-collector/apm-collector-core/src/test/resources/TestResourceFile.txt
@@ -0,0 +1 @@
+skywalking
\ No newline at end of file