Support configuration property file (#295)

Signed-off-by: marsishandsome <marsishandsome@gmail.com>

README.md

@@ -82,6 +82,21 @@ public class Main {
 
 The following includes JVM related parameters.
 
+#### tikv.configuration_file
+- tikv java client configuration file
+- default: null
+
+This parameter can be passed by `-Dtikv.configuration_file=/path/to/tikv_client_config.properties`.
+
+Here is an example of `tikv_client_config.properties`.
+
+```
+tikv.grpc.timeout_in_ms=150ms 
+tikv.grpc.forward_timeout_in_ms=200ms
+tikv.metrics.enable=true
+tikv.metrics.port=3140
+```
+
 #### tikv.pd.addresses
 - pd addresses, separated by comma
 - default: 127.0.0.1:2379

src/main/java/org/tikv/common/ConfigUtils.java

@@ -19,6 +19,8 @@ import org.tikv.common.util.BackOffer;
 import org.tikv.kvproto.Kvrpcpb;
 
 public class ConfigUtils {
+  public static final String TIKV_CONFIGURATION_FILE = "tikv.configuration_file";
+
   public static final String TIKV_PD_ADDRESSES = "tikv.pd.addresses";
   public static final String TIKV_GRPC_TIMEOUT = "tikv.grpc.timeout_in_ms";
   public static final String TIKV_GRPC_INGEST_TIMEOUT = "tikv.grpc.ingest_timeout_in_ms";

src/main/java/org/tikv/common/TiConfiguration.java

@@ -18,6 +18,8 @@ package org.tikv.common;
 import static org.tikv.common.ConfigUtils.*;
 
 import io.grpc.Metadata;
+import java.io.FileInputStream;
+import java.io.IOException;
 import java.io.Serializable;
 import java.net.URI;
 import java.util.*;
@@ -39,8 +41,11 @@ public class TiConfiguration implements Serializable {
       Metadata.Key.of("pd-forwarded-host", Metadata.ASCII_STRING_MARSHALLER);
 
   static {
+    // priority: system environment > config file > default
     loadFromSystemProperties();
+    loadFromConfigurationFile();
     loadFromDefaultProperties();
+    listAll();
   }
 
   private static void loadFromSystemProperties() {
@@ -51,6 +56,24 @@ public class TiConfiguration implements Serializable {
     }
   }
 
+  private static void loadFromConfigurationFile() {
+    Optional<String> file = getOption(TIKV_CONFIGURATION_FILE);
+    if (file.isPresent()) {
+      Properties properties = new Properties();
+      try {
+        properties.load(new FileInputStream(file.get()));
+      } catch (IOException e) {
+        logger.error("load config file error, path = " + file.get(), e);
+      }
+      for (String key : properties.stringPropertyNames()) {
+        if (key.startsWith("tikv.")) {
+          String value = properties.getProperty(key);
+          setIfMissing(key, value);
+        }
+      }
+    }
+  }
+
   private static void loadFromDefaultProperties() {
     setIfMissing(TIKV_PD_ADDRESSES, DEF_PD_ADDRESSES);
     setIfMissing(TIKV_GRPC_TIMEOUT, DEF_TIMEOUT);
@@ -94,7 +117,7 @@ public class TiConfiguration implements Serializable {
   }
 
   public static void listAll() {
-    logger.info(new ArrayList<>(settings.entrySet()).toString());
+    logger.warn("static configurations are:" + new ArrayList<>(settings.entrySet()).toString());
   }
 
   private static void set(String key, String value) {

src/test/java/org/tikv/common/TiConfigurationTest.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2021 PingCAP, Inc.
+ *
+ * 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,
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.tikv.common;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Ignore;
+
+public class TiConfigurationTest {
+
+  // Set `-Dtikv.configuration_file=src/test/resources/tikv_client_config.properties` to test
+  @Ignore
+  public void configFileTest() {
+    TiConfiguration conf = TiConfiguration.createRawDefault();
+    assertEquals("configFileTest", conf.getDBPrefix());
+  }
+}

src/test/resources/tikv_client_config.properties

@@ -0,0 +1 @@
+tikv.db_prefix=configFileTest