| 1 | package be.nikiroo.utils; |
| 2 | |
| 3 | /** |
| 4 | * A handler when a trace message is sent or when a recoverable exception was |
| 5 | * caught by the program. |
| 6 | * |
| 7 | * @author niki |
| 8 | */ |
| 9 | public class TraceHandler { |
| 10 | private final boolean showErrors; |
| 11 | private final boolean showErrorDetails; |
| 12 | private final int traceLevel; |
| 13 | |
| 14 | /** |
| 15 | * Create a default {@link TraceHandler} that will print errors on stderr |
| 16 | * (without details) and no traces. |
| 17 | */ |
| 18 | public TraceHandler() { |
| 19 | this(true, false, false); |
| 20 | } |
| 21 | |
| 22 | /** |
| 23 | * Create a default {@link TraceHandler}. |
| 24 | * |
| 25 | * @param showErrors |
| 26 | * show errors on stderr |
| 27 | * @param showErrorDetails |
| 28 | * show more details when printing errors |
| 29 | * @param showTraces |
| 30 | * show level 1 traces on stdout, or no traces at all |
| 31 | */ |
| 32 | public TraceHandler(boolean showErrors, boolean showErrorDetails, |
| 33 | boolean showTraces) { |
| 34 | this(showErrors, showErrorDetails, showTraces ? 1 : 0); |
| 35 | } |
| 36 | |
| 37 | /** |
| 38 | * Create a default {@link TraceHandler}. |
| 39 | * |
| 40 | * @param showErrors |
| 41 | * show errors on stderr |
| 42 | * @param showErrorDetails |
| 43 | * show more details when printing errors |
| 44 | * @param traceLevel |
| 45 | * show traces of this level or lower (0 means "no traces", |
| 46 | * higher means more traces) |
| 47 | */ |
| 48 | public TraceHandler(boolean showErrors, boolean showErrorDetails, |
| 49 | int traceLevel) { |
| 50 | this.showErrors = showErrors; |
| 51 | this.showErrorDetails = showErrorDetails; |
| 52 | this.traceLevel = Math.max(traceLevel, 0); |
| 53 | } |
| 54 | |
| 55 | /** |
| 56 | * The trace level of this {@link TraceHandler}. |
| 57 | * |
| 58 | * @return the level |
| 59 | */ |
| 60 | public int getTraceLevel() { |
| 61 | return traceLevel; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * An exception happened, log it. |
| 66 | * |
| 67 | * @param e |
| 68 | * the exception |
| 69 | */ |
| 70 | public void error(Exception e) { |
| 71 | if (showErrors) { |
| 72 | if (showErrorDetails) { |
| 73 | e.printStackTrace(); |
| 74 | } else { |
| 75 | error(e.getMessage()); |
| 76 | } |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * An error happened, log it. |
| 82 | * |
| 83 | * @param message |
| 84 | * the error message |
| 85 | */ |
| 86 | public void error(String message) { |
| 87 | if (showErrors) { |
| 88 | System.err.println(message); |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * A trace happened, show it. |
| 94 | * <p> |
| 95 | * By default, will only be effective if {@link TraceHandler#showTraces} is |
| 96 | * true |
| 97 | * <p> |
| 98 | * A call to this method is equivalent to a call to |
| 99 | * {@link TraceHandler#trace(String, int)} with a level of 1. |
| 100 | * |
| 101 | * @param message |
| 102 | * the trace message |
| 103 | */ |
| 104 | public void trace(String message) { |
| 105 | trace(message, 1); |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * A trace happened, show it. |
| 110 | * <p> |
| 111 | * By default, will only be effective if {@link TraceHandler#showTraces} is |
| 112 | * true and the level is lower or equal to {@link TraceHandler#traceLevel}. |
| 113 | * |
| 114 | * @param message |
| 115 | * the trace message |
| 116 | * @param level |
| 117 | * the trace level |
| 118 | */ |
| 119 | public void trace(String message, int level) { |
| 120 | if (traceLevel > 0 && level <= traceLevel) { |
| 121 | System.out.println(message); |
| 122 | } |
| 123 | } |
| 124 | } |