add test case. (#440)

build.gradle

@@ -123,7 +123,8 @@ subprojects {
     ]
 
     List junit = [
-            "junit:junit:4.12"
+            "junit:junit:4.12",
+            "com.github.stefanbirkner:system-rules:1.16.1"
     ]
 
     List log = [

eventmesh-common/src/test/java/org/apache/eventmesh/common/IPUtilTest.java

@@ -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.
+ */
+
+package org.apache.eventmesh.common;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.contrib.java.lang.system.EnvironmentVariables;
+
+public class IPUtilTest {
+
+    @Test
+    public void testDockerIP() {
+        EnvironmentVariables environmentVariables = new EnvironmentVariables();
+        environmentVariables.set("docker_host_ip", "dockHostIP");
+        Assert.assertEquals("dockHostIP", IPUtil.getLocalAddress());
+    }
+
+    @Test
+    public void testLocalhostIP() {
+        Assert.assertNotNull(IPUtil.getLocalAddress());
+    }
+
+}

eventmesh-common/src/test/java/org/apache/eventmesh/common/ThreadUtilTest.java

@@ -0,0 +1,59 @@
+/*
+ * 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.
+ */
+
+package org.apache.eventmesh.common;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class ThreadUtilTest {
+
+    @Test
+    public void testRandomSleep() {
+        TestThread testThread = new TestThread();
+        testThread.start();
+        try {
+            Thread.sleep(100L);
+            Assert.assertTrue(testThread.getSleepTime() >= 1);
+            Assert.assertTrue(testThread.getSleepTime() <= 50);
+        } catch (InterruptedException ignore) {
+        }
+    }
+
+    @Test
+    public void testPID() {
+        Assert.assertNotEquals(-1, ThreadUtil.getPID());
+    }
+
+    class TestThread extends Thread {
+
+        private long sleepTime;
+
+        public long getSleepTime() {
+            return sleepTime;
+        }
+
+        public void run() {
+            long startTime = System.currentTimeMillis();
+            try {
+                ThreadUtil.randomSleep(50);
+            } catch (Exception ignore) {
+            }
+            sleepTime = System.currentTimeMillis() - startTime;
+        }
+    }
+}

eventmesh-common/src/test/java/org/apache/eventmesh/common/protocol/tcp/codec/CodecTest.java

@@ -0,0 +1,43 @@
+/*
+ * 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.
+ */
+
+package org.apache.eventmesh.common.protocol.tcp.codec;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.PooledByteBufAllocator;
+import org.apache.eventmesh.common.protocol.tcp.Package;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.ArrayList;
+
+public class CodecTest {
+
+    @Test
+    public void testCodec() throws Exception {
+        Package testP = new Package();
+        Codec.Encoder ce = new Codec.Encoder();
+        ByteBuf buf = PooledByteBufAllocator.DEFAULT.buffer();
+        ce.encode(null, testP, buf);
+        Codec.Decoder cd = new Codec.Decoder();
+        ArrayList<Object> result = new ArrayList<>();
+        cd.decode(null, buf, result);
+        Assert.assertNotNull(result.get(0));
+        Assert.assertEquals(result.get(0).toString(), testP.toString());
+    }
+
+}