Update resolving logic of project name and polish SentinelConfig (#1437)

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

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

@@ -42,9 +42,13 @@ public final class SentinelConfig {
     public static final int APP_TYPE_COMMON = 0;
 
     private static final Map<String, String> props = new ConcurrentHashMap<>();
+
     private static int appType = APP_TYPE_COMMON;
+    private static String appName = "";
 
-    public static final String APP_TYPE = "csp.sentinel.app.type";
+    public static final String PROJECT_NAME_PROP_KEY = "project.name";
+    public static final String APP_NAME_PROP_KEY = "csp.sentinel.app.name";
+    public static final String APP_TYPE_PROP_KEY = "csp.sentinel.app.type";
     public static final String CHARSET = "csp.sentinel.charset";
     public static final String SINGLE_METRIC_FILE_SIZE = "csp.sentinel.metric.file.single.size";
     public static final String TOTAL_METRIC_FILE_COUNT = "csp.sentinel.metric.file.total.count";
@@ -52,27 +56,19 @@ public final class SentinelConfig {
     public static final String STATISTIC_MAX_RT = "csp.sentinel.statistic.max.rt";
     public static final String SPI_CLASSLOADER = "csp.sentinel.spi.classloader";
 
-    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;
-    static final int DEFAULT_COLD_FACTOR = 3;
-
-    private static String appName = "";
-    public static final String APP_NAME = "project.name";
-    public static final String SUN_JAVA_COMMAND = "sun.java.command";
-    private static final String JAR_SUFFIX_LOWER = ".jar";
-    private static final String JAR_SUFFIX_UPPER = ".JAR";
-
-    public static final int DEFAULT_STATISTIC_MAX_RT = 4900;
+    public static final String DEFAULT_CHARSET = "UTF-8";
+    public static final long DEFAULT_SINGLE_METRIC_FILE_SIZE = 1024 * 1024 * 50;
+    public static final int DEFAULT_TOTAL_METRIC_FILE_COUNT = 6;
+    public static final int DEFAULT_COLD_FACTOR = 3;
+    public static final int DEFAULT_STATISTIC_MAX_RT = 5000;
 
     static {
         try {
             initialize();
             loadProps();
+            resolveAppName();
             resolveAppType();
             RecordLog.info("[SentinelConfig] Application type resolved: " + appType);
-            resolveAppName();
-            RecordLog.info("[SentinelConfig] Application name resolved: " + appName);
         } catch (Throwable ex) {
             RecordLog.warn("[SentinelConfig] Failed to initialize", ex);
             ex.printStackTrace();
@@ -81,7 +77,7 @@ public final class SentinelConfig {
 
     private static void resolveAppType() {
         try {
-            String type = getConfig(APP_TYPE);
+            String type = getConfig(APP_TYPE_PROP_KEY);
             if (type == null) {
                 appType = APP_TYPE_COMMON;
                 return;
@@ -198,9 +194,7 @@ public final class SentinelConfig {
     }
 
     /**
-     * <p>Get the max RT value that Sentinel could accept.</p>
-     * <p>Response time that exceeds {@code statisticMaxRt} will be recorded as this value.
-     * The default value is {@link #DEFAULT_STATISTIC_MAX_RT}.</p>
+     * <p>Get the max RT value that Sentinel could accept for system BBR strategy.</p>
      *
      * @return the max allowed RT value
      * @since 1.4.1
@@ -221,12 +215,13 @@ public final class SentinelConfig {
     }
 
     /**
-     * method for getting application name. This class uses the flowing order to get app's name:
+     * Function for resolving project name. The order is elaborated below:
      *
      * <ol>
-     * <li>get {@code project.name} from System Properties, if not null, use the value as app name;</li>
-     * <li>get {@code project.name} from Properties file, if not null, use the value as app name;</li>
-     * <li>get {@code sun.java.command} from System properties, remove path, arguments and ".jar" or ".JAR"
+     * <li>Resolve the value from {@code CSP_SENTINEL_APP_NAME} system environment;</li>
+     * <li>Resolve the value from {@code csp.sentinel.app.name} system property;</li>
+     * <li>Resolve the value from {@code project.name} system property (for compatibility);</li>
+     * <li>Resolve the value from {@code sun.java.command} system property, then remove path, arguments and ".jar" or ".JAR"
      * suffix, use the result as app name. Note that whitespace in file name or path is not allowed, or a
      * wrong app name may be gotten, For example:
      * <p>
@@ -242,15 +237,31 @@ public final class SentinelConfig {
      * </li>
      * </ol>
      */
-    public static void resolveAppName() {
-
-        if (props.get(APP_NAME) != null) {
-            appName = props.get(APP_NAME);
+    private static void resolveAppName() {
+        // Priority: system env -> csp.sentinel.app.name -> project.name -> main class (or jar) name
+        String envKey = toEnvKey(APP_NAME_PROP_KEY);
+        String n = System.getenv(envKey);
+        if (!StringUtil.isBlank(n)) {
+            appName = n;
+            RecordLog.info("App name resolved from system env {}: {}", envKey, appName);
+            return;
+        }
+        n = props.get(APP_NAME_PROP_KEY);
+        if (!StringUtil.isBlank(n)) {
+            appName = n;
+            RecordLog.info("App name resolved from property {}: {}", APP_NAME_PROP_KEY, appName);
             return;
         }
-        // parse sun.java.command property
-        String command = System.getProperty(SUN_JAVA_COMMAND);
+        n = props.get(PROJECT_NAME_PROP_KEY);
+        if (!StringUtil.isBlank(n)) {
+            appName = n;
+            RecordLog.info("App name resolved from property {}: {}", PROJECT_NAME_PROP_KEY, appName);
+            return;
+        }
+        // Parse sun.java.command property by default.
+        String command = System.getProperty("sun.java.command");
         if (StringUtil.isBlank(command)) {
+            RecordLog.warn("Cannot resolve default appName from property sun.java.command");
             return;
         }
         command = command.split("\\s")[0];
@@ -258,16 +269,22 @@ public final class SentinelConfig {
         if (command.contains(separator)) {
             String[] strs;
             if ("\\".equals(separator)) {
+                // Handle separator in Windows.
                 strs = command.split("\\\\");
             } else {
                 strs = command.split(separator);
             }
             command = strs[strs.length - 1];
         }
-        if (command.endsWith(JAR_SUFFIX_LOWER) || command.endsWith(JAR_SUFFIX_UPPER)) {
+        if (command.toLowerCase().endsWith(".jar")) {
             command = command.substring(0, command.length() - 4);
         }
         appName = command;
+        RecordLog.info("App name resolved from default: {}", appName);
+    }
+
+    private static String toEnvKey(/*@NotBlank*/ String propKey) {
+        return propKey.toUpperCase().replace('.', '_');
     }
 
     private SentinelConfig() {}

sentinel-core/src/test/java/com/alibaba/csp/sentinel/ConfigPropertyHelper.java

@@ -32,11 +32,11 @@ import com.alibaba.csp.sentinel.util.AppNameUtil;
 public final class ConfigPropertyHelper {
 
     public static void setAppNameProperty(String appName) {
-        System.setProperty(SentinelConfig.APP_NAME, appName);
+        System.setProperty(SentinelConfig.APP_NAME_PROP_KEY, appName);
     }
 
     public static void clearAppNameProperty() {
-        System.clearProperty(SentinelConfig.APP_NAME);
+        System.clearProperty(SentinelConfig.APP_NAME_PROP_KEY);
     }
 
     public static void runWithConfig(Properties prop, String appName, Task task) throws Exception {

sentinel-core/src/test/java/com/alibaba/csp/sentinel/config/SentinelConfigTest.java

@@ -93,7 +93,7 @@ public class SentinelConfigTest {
             out.write("\n");
             out.write(buildPropertyStr(STATISTIC_MAX_RT, "6000"));
             out.write("\n");
-            out.write(buildPropertyStr(APP_NAME, "sentinel_test"));
+            out.write(buildPropertyStr(PROJECT_NAME_PROP_KEY, "sentinel_test"));
             out.flush();
             out.close();