From: Mathieu Baudier <mbaudier@argeo.org>
Date: Tue, 7 Jun 2022 10:50:29 +0000 (+0200)
Subject: Fallback mechanism in case System.getLogger is not supported (e.g.
X-Git-Tag: v2.3.10~200
X-Git-Url: https://git.argeo.org/?a=commitdiff_plain;h=2a5c276f3a47d31dfb4d7b247cca58cd317bb128;p=lgpl%2Fargeo-commons.git

Fallback mechanism in case System.getLogger is not supported (e.g.
Android).
---

diff --git a/org.argeo.api.cms/src/org/argeo/api/cms/CmsLog.java b/org.argeo.api.cms/src/org/argeo/api/cms/CmsLog.java
index 3454dfc61..1c88441f7 100644
--- a/org.argeo.api.cms/src/org/argeo/api/cms/CmsLog.java
+++ b/org.argeo.api.cms/src/org/argeo/api/cms/CmsLog.java
@@ -1,16 +1,17 @@
 package org.argeo.api.cms;
 
 import java.lang.System.Logger;
-import java.lang.System.Logger.Level;
 import java.util.Objects;
 import java.util.function.Supplier;
 
+import org.argeo.api.cms.SystemLogger.Level;
+
 /**
  * A Commons Logging / SLF4J style logging utilities wrapping a standard Java
  * platform {@link Logger}.
  */
 public interface CmsLog {
-	Logger getLogger();
+	SystemLogger getLogger();
 
 	default boolean isDebugEnabled() {
 		return getLogger().isLoggable(Level.DEBUG);
@@ -181,23 +182,13 @@ public interface CmsLog {
 	}
 
 	static CmsLog getLog(String name) {
-		Logger logger = System.getLogger(Objects.requireNonNull(name));
-		return new LoggerWrapper(logger);
-	}
-
-	/** A trivial implementation wrapping a platform logger. */
-	static class LoggerWrapper implements CmsLog {
-		private final Logger logger;
-
-		LoggerWrapper(Logger logger) {
-			this.logger = logger;
+		SystemLogger logger;
+		try {
+			logger = new RealSystemLogger(name);
+		} catch (NoSuchMethodError | NoClassDefFoundError e) {// Android
+			logger = new FallBackSystemLogger();
 		}
-
-		@Override
-		public Logger getLogger() {
-			return logger;
-		}
-
+		return new LoggerWrapper(logger);
 	}
 
 }
diff --git a/org.argeo.api.cms/src/org/argeo/api/cms/SystemLogger.java b/org.argeo.api.cms/src/org/argeo/api/cms/SystemLogger.java
new file mode 100644
index 000000000..9d6ca8dc2
--- /dev/null
+++ b/org.argeo.api.cms/src/org/argeo/api/cms/SystemLogger.java
@@ -0,0 +1,128 @@
+package org.argeo.api.cms;
+
+import java.lang.System.Logger;
+import java.util.Objects;
+import java.util.function.Supplier;
+
+/** Workaround because Android does not support {@link Logger}. */
+abstract class SystemLogger {
+	public enum Level {
+		ALL(Integer.MIN_VALUE, java.lang.System.Logger.Level.ALL), //
+		TRACE(400, java.lang.System.Logger.Level.TRACE), //
+		DEBUG(500, java.lang.System.Logger.Level.DEBUG), //
+		INFO(800, java.lang.System.Logger.Level.INFO), //
+		WARNING(900, java.lang.System.Logger.Level.WARNING), //
+		ERROR(1000, java.lang.System.Logger.Level.ERROR), //
+		OFF(Integer.MAX_VALUE, java.lang.System.Logger.Level.OFF); //
+
+		private final int severity;
+		private java.lang.System.Logger.Level systemLevel;
+
+		private Level(int severity, java.lang.System.Logger.Level systemLevel) {
+			this.severity = severity;
+			this.systemLevel = systemLevel;
+		}
+
+		public final int getSeverity() {
+			return severity;
+		}
+
+		public java.lang.System.Logger.Level getSystemLevel() {
+			return systemLevel;
+		}
+	}
+
+	public boolean isLoggable(Level level) {
+		return false;
+	}
+
+	public abstract void log(Level level, Supplier<String> msgSupplier, Throwable thrown);
+
+	public abstract void log(Level level, String msg, Throwable thrown);
+
+	public void log(Level level, String msg) {
+		log(level, msg, (Throwable) null);
+	}
+
+	public void log(Level level, Supplier<String> msgSupplier) {
+		log(level, msgSupplier, (Throwable) null);
+	}
+
+	public void log(Level level, Object obj) {
+		Objects.requireNonNull(obj);
+		log(level, obj.toString());
+	}
+
+	public void log(Level level, String format, Object... params) {
+		// FIXME implement it
+		String msg = null;
+		log(level, msg);
+	}
+
+}
+
+/** A trivial implementation wrapping a platform logger. */
+class LoggerWrapper implements CmsLog {
+	private final SystemLogger logger;
+
+	LoggerWrapper(SystemLogger logger) {
+		this.logger = logger;
+	}
+
+	@Override
+	public SystemLogger getLogger() {
+		return logger;
+	}
+
+}
+
+class RealSystemLogger extends SystemLogger {
+	final Logger logger;
+
+	RealSystemLogger(String name) {
+		logger = System.getLogger(name);
+	}
+
+	@Override
+	public boolean isLoggable(Level level) {
+		return logger.isLoggable(convertSystemLevel(level));
+	}
+
+	@Override
+	public void log(Level level, Supplier<String> msgSupplier, Throwable thrown) {
+		logger.log(convertSystemLevel(level), msgSupplier, thrown);
+	}
+
+	@Override
+	public void log(Level level, String msg, Throwable thrown) {
+		logger.log(convertSystemLevel(level), msg, thrown);
+	}
+
+	System.Logger.Level convertSystemLevel(Level level) {
+		return level.getSystemLevel();
+	}
+};
+
+class FallBackSystemLogger extends SystemLogger {
+	@Override
+	public void log(Level level, Supplier<String> msgSupplier, Throwable thrown) {
+		if (isLoggable(level))
+			if (thrown != null) {
+				System.err.println(msgSupplier.get());
+				thrown.printStackTrace();
+			} else {
+				System.out.println(msgSupplier.get());
+			}
+	}
+
+	@Override
+	public void log(Level level, String msg, Throwable thrown) {
+		if (isLoggable(level))
+			if (thrown != null) {
+				System.err.println(msg);
+				thrown.printStackTrace();
+			} else {
+				System.out.println(msg);
+			}
+	}
+}
\ No newline at end of file