Create a "deep print" utility routine for logging.

webapp/src/edu/cornell/mannlib/vitro/webapp/utils/log/LogUtils.java

@@ -0,0 +1,127 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.mannlib.vitro.webapp.utils.log;
+
+import java.lang.reflect.TypeVariable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.commons.lang.StringUtils;
+import org.apache.commons.logging.Log;
+
+/**
+ * Some static methods that might help with logging for debug purposes.
+ */
+public class LogUtils {
+	public static String deepFormatForLog(Log log, String level, Object o) {
+		if (!isLevelEnabled(log, level)) {
+			return "";
+		}
+		return new LogUtils(log).deepFormat(o);
+	}
+
+	private static boolean isLevelEnabled(Log log, String level) {
+		if ("fatal".equalsIgnoreCase(level)) {
+			return log.isFatalEnabled();
+		} else if ("error".equalsIgnoreCase(level)) {
+			return log.isErrorEnabled();
+		} else if ("warn".equalsIgnoreCase(level)) {
+			return log.isWarnEnabled();
+		} else if ("info".equalsIgnoreCase(level)) {
+			return log.isInfoEnabled();
+		} else if ("debug".equalsIgnoreCase(level)) {
+			return log.isDebugEnabled();
+		} else {
+			return log.isTraceEnabled();
+		}
+	}
+
+	private final Log log;
+	private final List<Object> dontFormatAgain = new ArrayList<Object>();
+
+	private LogUtils(Log log) {
+		this.log = log;
+	}
+
+	public String deepFormat(Object o) {
+		if (o == null) {
+			return "null";
+		}
+		if (o instanceof String) {
+			return "\"" + o + "\"";
+		}
+		if (dontFormatAgain.contains(o)) {
+			return "...";
+		}
+
+		dontFormatAgain.add(o);
+
+		if (o instanceof Collection<?>) {
+			return formatCollection((Collection<?>) o);
+		}
+		if (o instanceof Map<?, ?>) {
+			return formatMap((Map<?, ?>) (o));
+		}
+		if (o.getClass().isArray()
+				&& (!o.getClass().getComponentType().isPrimitive())) {
+			return formatClass(o) + ": " + Arrays.deepToString((Object[]) o);
+		}
+		return formatClass(o) + ": " + String.valueOf(o);
+	}
+
+	private String formatClass(Object o) {
+		if (o == null) {
+			return "";
+		}
+
+		Class<?> clazz = o.getClass();
+		TypeVariable<?>[] generics = clazz.getTypeParameters();
+
+		if (generics.length == 0) {
+			return clazz.getName();
+		} else {
+			return clazz.getName() + '<' + StringUtils.join(generics, ", ")
+					+ '>';
+		}
+	}
+
+	private String formatCollection(Collection<?> collection) {
+		StringBuilder result = new StringBuilder(formatClass(collection));
+		result.append(": ");
+
+		result.append('{');
+		for (Iterator<?> it = collection.iterator(); it.hasNext();) {
+			result.append(deepFormat(it.next()));
+			if (it.hasNext()) {
+				result.append(", ");
+			}
+		}
+		result.append('}');
+
+		return result.toString();
+	}
+
+	private String formatMap(Map<?, ?> map) {
+		StringBuilder result = new StringBuilder(formatClass(map));
+		result.append(": ");
+
+		result.append('{');
+		for (Iterator<?> it = map.keySet().iterator(); it.hasNext();) {
+			Object key = it.next();
+			result.append(deepFormat(key));
+			result.append('=');
+			result.append(deepFormat(map.get(key)));
+			if (it.hasNext()) {
+				result.append(", ");
+			}
+		}
+		result.append('}');
+
+		return result.toString();
+	}
+
+}