1 files changed, 122 insertions, 0 deletions
diff --git a/javaparser-core/src/main/java/com/github/javaparser/utils/Log.java b/javaparser-core/src/main/java/com/github/javaparser/utils/Log.java
new file mode 100644
index 000000000..12a9cdc85
--- /dev/null
+++ b/javaparser-core/src/main/java/com/github/javaparser/utils/Log.java
@@ -0,0 +1,122 @@
+package com.github.javaparser.utils;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+import static com.github.javaparser.utils.CodeGenerationUtils.f;
+
+/**
+ * To avoid dependencies on logging frameworks, we have invented yet another logging framework :-)
+ */
+public class Log {
+    /**
+     * This adapter logs to standard out and standard error.
+     */
+    public static class StandardOutStandardErrorAdapter implements Adapter {
+        @Override
+        public void info(String message) {
+            System.out.println(message);
+        }
+
+        @Override
+        public void trace(String message) {
+            System.out.println(message);
+        }
+
+        @Override
+        public void error(Throwable throwable, String message) {
+            if (message == null) {
+                System.err.println(throwable.getMessage());
+                printStackTrace(throwable);
+            } else if (throwable == null) {
+                System.err.println(message);
+            } else {
+                System.err.println(message + ":" + throwable.getMessage());
+                printStackTrace(throwable);
+            }
+        }
+
+        private void printStackTrace(Throwable throwable) {
+            try (StringWriter sw = new StringWriter(); PrintWriter pw = new PrintWriter(sw)) {
+                throwable.printStackTrace(pw);
+                trace(sw.toString());
+            } catch (IOException e) {
+                throw new AssertionError("Error in logging library");
+            }
+        }
+    }
+
+    /**
+     * This adapter logs nothing.
+     */
+    public static class SilentAdapter implements Adapter {
+        @Override
+        public void info(String message) {
+        }
+
+        @Override
+        public void trace(String message) {
+        }
+
+        @Override
+        public void error(Throwable throwable, String f) {
+        }
+    }
+
+    public interface Adapter {
+
+        void info(String message);
+
+        void trace(String message);
+
+        /**
+         * Both can be null.
+         */
+        void error(Throwable throwable, String f);
+    }
+
+    private static Adapter CURRENT_ADAPTER = new SilentAdapter();
+
+    /**
+     * Change how logging is handled. You can set your own implementation that forwards to your logging library.
+     */
+    public static void setAdapter(Adapter adapter) {
+        CURRENT_ADAPTER = adapter;
+    }
+
+    /**
+     * For logging information that may help solving a problem.
+     */
+    public static void trace(String format, Object... args) {
+        CURRENT_ADAPTER.trace(f(format, args));
+    }
+
+    /**
+     * For logging things that are nice to see scrolling by.
+     */
+    public static void info(String format, Object... args) {
+        CURRENT_ADAPTER.info(f(format, args));
+    }
+
+    /**
+     * For drawing attention to an error.
+     */
+    public static void error(Throwable throwable) {
+        CURRENT_ADAPTER.error(throwable, null);
+    }
+
+    /**
+     * For drawing attention to an error that you don't have an exception for.
+     */
+    public static void error(Throwable throwable, String format, Object... args) {
+        CURRENT_ADAPTER.error(throwable, f(format, args));
+    }
+
+    /**
+     * For drawing attention to an error that you don't have an exception for.
+     */
+    public static void error(String format, Object... args) {
+        CURRENT_ADAPTER.error(null, f(format, args));
+    }
+}