Feature: custom server file location

apollo-core/src/main/java/com/ctrip/framework/foundation/internals/provider/DefaultServerProvider.java

@@ -1,5 +1,24 @@
+/*
+ * 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 com.ctrip.framework.foundation.internals.provider;
 
+import com.google.common.base.Strings;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.InputStream;
@@ -16,20 +35,47 @@
 
 public class DefaultServerProvider implements ServerProvider {
   private static final Logger logger = LoggerFactory.getLogger(DefaultServerProvider.class);
-  private static final String SERVER_PROPERTIES_LINUX = "/opt/settings/server.properties";
-  private static final String SERVER_PROPERTIES_WINDOWS = "C:/opt/settings/server.properties";
 
+  static final String DEFAULT_SERVER_PROPERTIES_PATH_ON_LINUX = "/opt/settings/server.properties";
+  static final String DEFAULT_SERVER_PROPERTIES_PATH_ON_WINDOWS = "C:/opt/settings/server.properties";
   private String m_env;
   private String m_dc;
 
-  private Properties m_serverProperties = new Properties();
+  private final Properties m_serverProperties = new Properties();
+
+  String getServerPropertiesPath() {
+    final String serverPropertiesPath = getCustomizedServerPropertiesPath();
+
+    if (!Strings.isNullOrEmpty(serverPropertiesPath)) {
+      return serverPropertiesPath;
+    }
+
+    return Utils.isOSWindows() ? DEFAULT_SERVER_PROPERTIES_PATH_ON_WINDOWS : DEFAULT_SERVER_PROPERTIES_PATH_ON_LINUX;
+  }
+
+  private String getCustomizedServerPropertiesPath() {
+    // 1. Get from System Property
+    final String serverPropertiesPathFromSystemProperty = System
+        .getProperty("apollo.path.server.properties");
+    if (!Strings.isNullOrEmpty(serverPropertiesPathFromSystemProperty)) {
+      return serverPropertiesPathFromSystemProperty;
+    }
+
+    // 2. Get from OS environment variable
+    final String serverPropertiesPathFromEnvironment = System
+        .getenv("APOLLO_PATH_SERVER_PROPERTIES");
+    if (!Strings.isNullOrEmpty(serverPropertiesPathFromEnvironment)) {
+      return serverPropertiesPathFromEnvironment;
+    }
+
+    // last, return null if there is no custom value
+    return null;
+  }
 
   @Override
   public void initialize() {
     try {
-      String path = Utils.isOSWindows() ? SERVER_PROPERTIES_WINDOWS : SERVER_PROPERTIES_LINUX;
-
-      File file = new File(path);
+      File file = new File(this.getServerPropertiesPath());
       if (file.exists() && file.canRead()) {
         logger.info("Loading {}", file.getAbsolutePath());
         FileInputStream fis = new FileInputStream(file);

apollo-core/src/test/java/com/ctrip/framework/foundation/internals/provider/DefaultServerProviderTest.java

@@ -1,10 +1,13 @@
 package com.ctrip.framework.foundation.internals.provider;
 
+import static com.ctrip.framework.foundation.internals.provider.DefaultServerProvider.DEFAULT_SERVER_PROPERTIES_PATH_ON_LINUX;
+import static com.ctrip.framework.foundation.internals.provider.DefaultServerProvider.DEFAULT_SERVER_PROPERTIES_PATH_ON_WINDOWS;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
+import com.ctrip.framework.foundation.internals.Utils;
 import java.io.File;
 import java.io.FileInputStream;
 
@@ -31,6 +34,20 @@ public void tearDown() throws Exception {
   private void cleanUp() {
     System.clearProperty("env");
     System.clearProperty("idc");
+    System.clearProperty("apollo.path.server.properties");
+  }
+
+  @Test
+  public void testGetServerPropertiesPathDefault() {
+    assertEquals(Utils.isOSWindows() ? DEFAULT_SERVER_PROPERTIES_PATH_ON_WINDOWS
+        : DEFAULT_SERVER_PROPERTIES_PATH_ON_LINUX, defaultServerProvider.getServerPropertiesPath());
+  }
+
+  @Test
+  public void testGetServerPropertiesPathCustom() {
+    final String customPath = "/simple/custom/path";
+    System.setProperty("apollo.path.server.properties", customPath);
+    assertEquals(customPath, defaultServerProvider.getServerPropertiesPath());
   }
 
   @Test