Code refinement for Sentinel config classes

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

sentinel-core/src/main/java/com/alibaba/csp/sentinel/config/SentinelConfig.java

@@ -24,8 +24,8 @@ import java.util.Properties;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
- * The universal local config center of Sentinel. The config is retrieved from command line arguments
- * and {@code ${user.home}/logs/csp/${appName}.properties} file by default.
+ * The universal local configuration center of Sentinel. The config is retrieved from command line arguments
+ * and customized properties file by default.
  *
  * @author leyou
  * @author Eric Zhao
@@ -49,7 +49,6 @@ public class SentinelConfig {
     public static final String COLD_FACTOR = "csp.sentinel.flow.cold.factor";
     public static final String STATISTIC_MAX_RT = "csp.sentinel.statistic.max.rt";
 
-
     static final String DEFAULT_CHARSET = "UTF-8";
     static final long DEFAULT_SINGLE_METRIC_FILE_SIZE = 1024 * 1024 * 50;
     static final int DEFAULT_TOTAL_METRIC_FILE_COUNT = 6;
@@ -98,7 +97,6 @@ public class SentinelConfig {
         for (Object key : properties.keySet()) {
             setConfig((String) key, (String) properties.get(key));
         }
-
     }
 
     /**

sentinel-core/src/main/java/com/alibaba/csp/sentinel/config/SentinelConfigLoader.java

@@ -28,22 +28,19 @@ import java.util.concurrent.CopyOnWriteArraySet;
 import static com.alibaba.csp.sentinel.util.ConfigUtil.addSeparator;
 
 /**
- * <p>
- * class responsible for loading the Sentinel Core configuration
- * </p>
+ * <p>The loader that responsible for loading Sentinel common configurations.</p>
  *
  * @author lianglin
  * @since 1.7.0
  */
-public class SentinelConfigLoader {
+public final class SentinelConfigLoader {
 
+    public static final String SENTINEL_CONFIG = "csp.sentinel.config.file";
 
     private static final String DIR_NAME = "logs" + File.separator + "csp";
     private static final String USER_HOME = "user.home";
 
-    public static final String SENTINEL_CONFIG = "csp.sentinel.config.file";
-    private static String DEFAULT_SENTINEL_CONFIG_FILE = "classpath:sentinel.properties";
-
+    private static final String DEFAULT_SENTINEL_CONFIG_FILE = "classpath:sentinel.properties";
 
     private static Properties properties = new Properties();
 
@@ -51,9 +48,7 @@ public class SentinelConfigLoader {
         load();
     }
 
-
     private static void load() {
-
         String fileName = System.getProperty(SENTINEL_CONFIG);
         if (StringUtil.isBlank(fileName)) {
             fileName = DEFAULT_SENTINEL_CONFIG_FILE;
@@ -61,7 +56,7 @@ public class SentinelConfigLoader {
 
         Properties p = ConfigUtil.loadProperties(fileName);
 
-        //old version config file
+        // Compatible with legacy config file path.
         if (p == null) {
             String path = addSeparator(System.getProperty(USER_HOME)) + DIR_NAME + File.separator;
             fileName = path + AppNameUtil.getAppName() + ".properties";
@@ -72,6 +67,7 @@ public class SentinelConfigLoader {
         }
 
         if (p != null && !p.isEmpty()) {
+            RecordLog.info("[SentinelConfigLoader] Loading Sentinel config from " + fileName);
             properties.putAll(p);
         }
 
@@ -81,7 +77,8 @@ public class SentinelConfigLoader {
             String oldConfigValue = properties.getProperty(configKey);
             properties.put(configKey, newConfigValue);
             if (oldConfigValue != null) {
-                RecordLog.info("[SentinelConfig] JVM parameter overrides {0}: {1} -> {2}", configKey, oldConfigValue, newConfigValue);
+                RecordLog.info("[SentinelConfigLoader] JVM parameter overrides {0}: {1} -> {2}",
+                        configKey, oldConfigValue, newConfigValue);
             }
         }
     }

sentinel-core/src/main/java/com/alibaba/csp/sentinel/log/LogBase.java

@@ -27,39 +27,43 @@ import java.util.logging.Logger;
 import static com.alibaba.csp.sentinel.util.ConfigUtil.addSeparator;
 
 /**
- * Default log base dir is ${user.home}/logs/csp/, we can use {@link #LOG_DIR} System property to override it.
- * Default log file name dose not contain pid, but if multi instances of the same app are running in the same
- * machine, we may want to distinguish the log file by pid number, in this case, {@link #LOG_NAME_USE_PID}
- * System property could be configured as "true" to turn on this switch.
+ * <p>The base class for logging.</p>
+ *
+ * <p>
+ * The default log base directory is {@code ${user.home}/logs/csp/}. We can use the {@link #LOG_DIR}
+ * property to override it. The default log file name dose not contain pid, but if multi-instances of the same service
+ * are running in the same machine, we may want to distinguish the log file by process ID number.
+ * In this case, {@link #LOG_NAME_USE_PID} property could be configured as "true" to turn on this switch.
+ * </p>
  *
  * @author leyou
  */
 public class LogBase {
 
-
-    private static final String DIR_NAME = "logs" + File.separator + "csp";
     public static final String LOG_DIR = "csp.sentinel.log.dir";
     public static final String LOG_NAME_USE_PID = "csp.sentinel.log.use.pid";
     public static final String LOG_OUTPUT_TYPE = "csp.sentinel.log.output.type";
     public static final String LOG_CHARSET = "csp.sentinel.log.charset";
-    public static final String USER_HOME = "user.home";
 
     /**
-     * Output biz log(RecordLog,CommandCenterLog) to file
+     * Output biz log (e.g. RecordLog and CommandCenterLog) to file.
      */
     public static final String LOG_OUTPUT_TYPE_FILE = "file";
     /**
-     * Output biz log(RecordLog,CommandCenterLog) to console
+     * Output biz log (e.g. RecordLog and CommandCenterLog) to console.
      */
     public static final String LOG_OUTPUT_TYPE_CONSOLE = "console";
     public static final String LOG_CHARSET_UTF8 = "utf-8";
 
+    private static final String DIR_NAME = "logs" + File.separator + "csp";
+    private static final String USER_HOME = "user.home";
+
+
     private static boolean logNameUsePid;
     private static String logOutputType;
     private static String logBaseDir;
     private static String logCharSet;
 
-
     static {
         try {
             initialize();
@@ -78,15 +82,13 @@ public class LogBase {
     }
 
     private static void loadProperties() {
-
         Properties properties = LogConfigLoader.getProperties();
 
         logOutputType = properties.get(LOG_OUTPUT_TYPE) == null ? logOutputType : properties.getProperty(LOG_OUTPUT_TYPE);
         if (!LOG_OUTPUT_TYPE_FILE.equalsIgnoreCase(logOutputType) && !LOG_OUTPUT_TYPE_CONSOLE.equalsIgnoreCase(logOutputType)) {
             logOutputType = LOG_OUTPUT_TYPE_FILE;
         }
-        System.out.println("INFO: log out type is: " + logOutputType);
-
+        System.out.println("INFO: log output type is: " + logOutputType);
 
         logCharSet = properties.getProperty(LOG_CHARSET) == null ? logCharSet : properties.getProperty(LOG_CHARSET);
         System.out.println("INFO: log charset is: " + logCharSet);
@@ -106,48 +108,45 @@ public class LogBase {
         String usePid = properties.getProperty(LOG_NAME_USE_PID);
         logNameUsePid = "true".equalsIgnoreCase(usePid);
         System.out.println("INFO: log name use pid is: " + logNameUsePid);
-
-
     }
 
 
     /**
-     * Whether log file name should contain pid. This switch is configured by {@link #LOG_NAME_USE_PID} System property.
+     * Whether log file name should contain pid. This switch is configured by {@link #LOG_NAME_USE_PID} system property.
      *
-     * @return if log file name should contain pid, return true, otherwise return false.
+     * @return true if log file name should contain pid, return true, otherwise false
      */
     public static boolean isLogNameUsePid() {
         return logNameUsePid;
     }
 
     /**
-     * Get log file base directory path, the returned path is guaranteed end with {@link File#separator}
+     * Get the log file base directory path, which is guaranteed ended with {@link File#separator}.
      *
-     * @return log file base directory path.
+     * @return log file base directory path
      */
     public static String getLogBaseDir() {
         return logBaseDir;
     }
 
     /**
-     * Get log file output type the default value is "file"
+     * Get the log file output type.
      *
-     * @return
+     * @return log output type, "file" by default
      */
     public static String getLogOutputType() {
         return logOutputType;
     }
 
     /**
-     * Get log file charSet the default value is utf-8
+     * Get the log file charset.
      *
-     * @return
+     * @return the log file charset, "utf-8" by default
      */
     public static String getLogCharset() {
         return logCharSet;
     }
 
-
     protected static void log(Logger logger, Handler handler, Level level, String detail, Object... params) {
         if (detail == null) {
             return;
@@ -209,5 +208,4 @@ public class LogBase {
         return handler;
     }
 
-
 }

sentinel-core/src/main/java/com/alibaba/csp/sentinel/log/LogConfigLoader.java

@@ -23,21 +23,17 @@ import java.util.Properties;
 import java.util.concurrent.CopyOnWriteArraySet;
 
 /**
- * <p>
- * class responsible for loading the Log configuration.
- * </p>
+ * <p>The loader that responsible for loading Sentinel log configurations.</p>
  *
  * @author lianglin
  * @since 1.7.0
  */
 public class LogConfigLoader {
 
-
     public static final String LOG_CONFIG = "csp.sentinel.config.file";
 
     private static final String DEFAULT_LOG_CONFIG_FILE = "classpath:sentinel.properties";
 
-
     private static final Properties properties = new Properties();
 
     static {
@@ -45,7 +41,6 @@ public class LogConfigLoader {
     }
 
     private static void load() {
-
         String file = System.getProperty(LOG_CONFIG);
         if (StringUtil.isBlank(file)) {
             file = DEFAULT_LOG_CONFIG_FILE;
@@ -60,19 +55,11 @@ public class LogConfigLoader {
         for (Map.Entry<Object, Object> entry : copy) {
             String configKey = entry.getKey().toString();
             String newConfigValue = entry.getValue().toString();
-            String oldConfigValue = properties.getProperty(configKey);
             properties.put(configKey, newConfigValue);
-            if (oldConfigValue != null) {
-                System.out.println("[LogConfig] JVM parameter overrides: " + configKey + " " + oldConfigValue + " -> " + newConfigValue);
-            }
         }
-
-
     }
 
     public static Properties getProperties() {
         return properties;
     }
-
-
 }

sentinel-core/src/main/java/com/alibaba/csp/sentinel/util/ConfigUtil.java

@@ -26,7 +26,7 @@ import java.util.Properties;
 
 /**
  * <p>
- * util for loading config
+ * Util class for loading configuration from file or command arguments.
  * </p>
  *
  * @author lianglin
@@ -34,14 +34,14 @@ import java.util.Properties;
  */
 public final class ConfigUtil {
 
-
     public static final String CLASSPATH_FILE_FLAG = "classpath:";
 
     /**
-     * Return null if the file not exist
+     * <p>Load the properties from provided file.</p>
+     * <p>Currently it supports reading from classpath file or local file.</p>
      *
-     * @param fileName
-     * @return
+     * @param fileName valid file path
+     * @return the retrieved properties from the file; null if the file not exist
      */
     public static Properties loadProperties(String fileName) {
         if (StringUtil.isNotBlank(fileName)) {
@@ -66,12 +66,9 @@ public final class ConfigUtil {
                 return null;
             }
 
-            FileInputStream input = new FileInputStream(file);
-            try {
+            try (FileInputStream input = new FileInputStream(file)) {
                 properties = new Properties();
                 properties.load(input);
-            } finally {
-                input.close();
             }
         } catch (Throwable e) {
             e.printStackTrace();
@@ -81,13 +78,12 @@ public final class ConfigUtil {
 
 
     private static Properties loadPropertiesFromClasspathFile(String fileName) {
-
         fileName = fileName.substring(CLASSPATH_FILE_FLAG.length()).trim();
 
-        List<URL> list = new ArrayList<URL>();
+        List<URL> list = new ArrayList<>();
         try {
             Enumeration<URL> urls = getClassLoader().getResources(fileName);
-            list = new ArrayList<URL>();
+            list = new ArrayList<>();
             while (urls.hasMoreElements()) {
                 list.add(urls.nextElement());
             }
@@ -143,5 +139,5 @@ public final class ConfigUtil {
         return dir;
     }
 
-
+    private ConfigUtil() {}
 }