X-Git-Url: http://git.nikiroo.be/?p=fanfix.git;a=blobdiff_plain;f=src%2Fbe%2Fnikiroo%2Futils%2FTraceHandler.java;fp=src%2Fbe%2Fnikiroo%2Futils%2FTraceHandler.java;h=0a09712d5218013992493838c75ad9aa0ad92527;hp=0000000000000000000000000000000000000000;hb=d46b7b96f94e88a776bcd2dfd756549ffb300cc9;hpb=c9994f27667bc421bcd448d39e55774fddf5c431

diff --git a/src/be/nikiroo/utils/TraceHandler.java b/src/be/nikiroo/utils/TraceHandler.java
new file mode 100644
index 0000000..0a09712
--- /dev/null
+++ b/src/be/nikiroo/utils/TraceHandler.java
@@ -0,0 +1,156 @@
+package be.nikiroo.utils;
+
+/**
+ * A handler when a trace message is sent or when a recoverable exception was
+ * caught by the program.
+ * 
+ * @author niki
+ */
+public class TraceHandler {
+	private final boolean showErrors;
+	private final boolean showErrorDetails;
+	private final int traceLevel;
+	private final int maxPrintSize;
+
+	/**
+	 * Create a default {@link TraceHandler} that will print errors on stderr
+	 * (without details) and no traces.
+	 */
+	public TraceHandler() {
+		this(true, false, false);
+	}
+
+	/**
+	 * Create a default {@link TraceHandler}.
+	 * 
+	 * @param showErrors
+	 *            show errors on stderr
+	 * @param showErrorDetails
+	 *            show more details when printing errors
+	 * @param showTraces
+	 *            show level 1 traces on stderr, or no traces at all
+	 */
+	public TraceHandler(boolean showErrors, boolean showErrorDetails,
+			boolean showTraces) {
+		this(showErrors, showErrorDetails, showTraces ? 1 : 0);
+	}
+
+	/**
+	 * Create a default {@link TraceHandler}.
+	 * 
+	 * @param showErrors
+	 *            show errors on stderr
+	 * @param showErrorDetails
+	 *            show more details when printing errors
+	 * @param traceLevel
+	 *            show traces of this level or lower (0 means "no traces",
+	 *            higher means more traces)
+	 */
+	public TraceHandler(boolean showErrors, boolean showErrorDetails,
+			int traceLevel) {
+		this(showErrors, showErrorDetails, traceLevel, -1);
+	}
+
+	/**
+	 * Create a default {@link TraceHandler}.
+	 * 
+	 * @param showErrors
+	 *            show errors on stderr
+	 * @param showErrorDetails
+	 *            show more details when printing errors
+	 * @param traceLevel
+	 *            show traces of this level or lower (0 means "no traces",
+	 *            higher means more traces)
+	 * @param maxPrintSize
+	 *            the maximum size at which to truncate traces data (or -1 for
+	 *            "no limit")
+	 */
+	public TraceHandler(boolean showErrors, boolean showErrorDetails,
+			int traceLevel, int maxPrintSize) {
+		this.showErrors = showErrors;
+		this.showErrorDetails = showErrorDetails;
+		this.traceLevel = Math.max(traceLevel, 0);
+		this.maxPrintSize = maxPrintSize;
+	}
+
+	/**
+	 * The trace level of this {@link TraceHandler}.
+	 * 
+	 * @return the level
+	 */
+	public int getTraceLevel() {
+		return traceLevel;
+	}
+
+	/**
+	 * An exception happened, log it.
+	 * 
+	 * @param e
+	 *            the exception
+	 */
+	public void error(Exception e) {
+		if (showErrors) {
+			if (showErrorDetails) {
+				long now = System.currentTimeMillis();
+				System.err.print(StringUtils.fromTime(now) + ": ");
+				e.printStackTrace();
+			} else {
+				error(e.toString());
+			}
+		}
+	}
+
+	/**
+	 * An error happened, log it.
+	 * 
+	 * @param message
+	 *            the error message
+	 */
+	public void error(String message) {
+		if (showErrors) {
+			long now = System.currentTimeMillis();
+			System.err.println(StringUtils.fromTime(now) + ": " + message);
+		}
+	}
+
+	/**
+	 * A trace happened, show it.
+	 * <p>
+	 * By default, will only be effective if {@link TraceHandler#traceLevel} is
+	 * not 0.
+	 * <p>
+	 * A call to this method is equivalent to a call to
+	 * {@link TraceHandler#trace(String, int)} with a level of 1.
+	 * 
+	 * @param message
+	 *            the trace message
+	 */
+	public void trace(String message) {
+		trace(message, 1);
+	}
+
+	/**
+	 * A trace happened, show it.
+	 * <p>
+	 * By default, will only be effective if {@link TraceHandler#traceLevel} is
+	 * not 0 and the level is lower or equal to it.
+	 * 
+	 * @param message
+	 *            the trace message
+	 * @param level
+	 *            the trace level
+	 */
+	public void trace(String message, int level) {
+		if (traceLevel > 0 && level <= traceLevel) {
+			long now = System.currentTimeMillis();
+			System.err.print(StringUtils.fromTime(now) + ": ");
+			if (maxPrintSize > 0 && message.length() > maxPrintSize) {
+
+				System.err
+						.println(message.substring(0, maxPrintSize) + "[...]");
+			} else {
+				System.err.println(message);
+			}
+		}
+	}
+}