Java tutorial
package org.marketcetera.util.test; import java.util.NoSuchElementException; import org.apache.commons.lang.SystemUtils; import org.apache.log4j.Level; import org.apache.log4j.Logger; import org.apache.log4j.spi.LoggingEvent; import static org.junit.Assert.*; /** * A log message test helper. * * @author tlerios@marketcetera.com * @author anshul@marketcetera.com * @since 2.0.0 * @version $Id$ */ /* $License$ */ public class LogTestAssist { // INSTANCE DATA. private final MemoryAppender mAppender = new MemoryAppender(); // CONSTRUCTORS. /** * Creates a new helper which tracks the log events sent out to * the logger with the given name at the given optional threshold * level. * * @param name The logger name. * @param level The level. It may be null, in which case logger's * threshold level is not altered. */ public LogTestAssist(String name, Level level) { trackLogger(name, level); } /** * Creates a new helper which tracks the log events sent out to * the logger with the given name. * * @param name The logger name. */ public LogTestAssist(String name) { this(name, null); } /** * Creates a new helper which doesn't track any logger output. The * helper can be configured to track logger output using {@link * #trackLogger(String,org.apache.log4j.Level)}. */ public LogTestAssist() { } // CLASS METHODS. /** * Sets the level of the root logger to the given level. * * @param level The level. */ public static void setDefaultLevel(Level level) { Logger.getRootLogger().setLevel(level); } /** * Sets the level of the logger with the given name to the given * level. * * @param name The logger name. * @param level The level. */ public static void setLevel(String name, Level level) { Logger.getLogger(name).setLevel(level); } /** * Asserts that the contents of the given event match the given * expected level, logger name, message, and location. * * @param event The event. * @param level The expected level. Use null to indicate "don't * care". * @param logger The expected logger name. Use null to indicate * "don't care". * @param message The expected message. Use null to indicate * "don't care". * @param location The expected location. Use null to indicate * "don't care". */ public static void assertEvent(LoggingEvent event, Level level, String logger, String message, String location) { if (level != null) { assertEquals(level, event.getLevel()); } if (logger != null) { assertEquals(logger, event.getLoggerName()); } if (message != null) { assertEquals(message, event.getMessage()); } if (location != null) { assertEquals(location, event.getLocationInformation().getClassName()); } } // INSTANCE METHODS. /** * Starts tracking log events sent out to the logger with the * given name at the given optional threshold level. * * @param name The logger name. * @param level The level. It may be null, in which case logger's * threshold level is not altered. */ public void trackLogger(String name, Level level) { Logger logger = Logger.getLogger(name); logger.addAppender(getAppender()); if (level != null) { logger.setLevel(level); } } /** * Starts tracking log events sent out to the logger with the * given name. * * @param name The logger name. */ public void trackLogger(String name) { trackLogger(name, null); } /** * Clears the contents of the receiver's collector. */ public void resetAppender() { getAppender().clear(); } /** * Returns a string with all the events of the receiver's * collector. * * @return The string. */ public String getEventsAsString() { StringBuilder builder = new StringBuilder(); builder.append("Event count: "); //$NON-NLS-1$ builder.append(getAppender().getEvents().size()); int i = 0; for (LoggingEvent event : getAppender().getEvents()) { builder.append(SystemUtils.LINE_SEPARATOR); builder.append("Event "); //$NON-NLS-1$ builder.append(i++); builder.append(": level: "); //$NON-NLS-1$ builder.append(event.getLevel()); builder.append("; logger: "); //$NON-NLS-1$ builder.append(event.getLoggerName()); builder.append("; message: "); //$NON-NLS-1$ builder.append(event.getMessage()); builder.append("; location: "); //$NON-NLS-1$ builder.append(event.getLocationInformation().getClassName()); } return builder.toString(); } /** * Returns the receiver's collector (appender) of retained events. * * @return The appender. */ public MemoryAppender getAppender() { return mAppender; } /** * Asserts that the receiver's collector contains the given number * of events. * * @param count The number of events. */ public void assertEventCount(int count) { if (getAppender().getEvents().size() == count) { return; } StringBuilder builder = new StringBuilder(); builder.append("Incorrect event count; expected "); //$NON-NLS-1$ builder.append(count); builder.append(" actual "); //$NON-NLS-1$ builder.append(SystemUtils.LINE_SEPARATOR); builder.append(getEventsAsString()); fail(builder.toString()); } /** * Asserts that the receiver's collector contains no events. */ public void assertNoEvents() { assertEventCount(0); } /** * Asserts that the contents of the receiver's collector's most * recent event match the given expected level, logger name, * message, and location. The assertion fails if the receiver has * no events. * * @param level The expected level. Use null to indicate "don't * care". * @param logger The expected logger name. Use null to indicate * "don't care". * @param message The expected message. Use null to indicate * "don't care". * @param location The expected location. Use null to indicate * "don't care". */ public void assertLastEvent(Level level, String logger, String message, String location) { LoggingEvent event = null; try { event = getAppender().getEvents().getLast(); } catch (NoSuchElementException ex) { fail("List is empty"); //$NON-NLS-1$ } assertEvent(event, level, logger, message, location); } /** * Asserts that at least one of the receiver's collector's events * matches the given expected level, logger name, message, and * location. If the collector has no events, the assertion fails. * * @param level The expected level. Use null to indicate "don't * care". * @param logger The expected logger name. Use null to indicate * "don't care". * @param message The expected message. Use null to indicate * "don't care". * @param location The expected location. Use null to indicate * "don't care". */ public void assertSomeEvent(Level level, String logger, String message, String location) { for (LoggingEvent event : getAppender().getEvents()) { if (((level == null) || level.equals(event.getLevel())) && ((logger == null) || logger.equals(event.getLoggerName())) && ((message == null) || message.equals(event.getMessage())) && ((location == null) || location.equals(event.getLocationInformation().getClassName()))) { return; } } fail("No matches against given event. Events are:" + //$NON-NLS-1$ SystemUtils.LINE_SEPARATOR + getEventsAsString()); } /** * Asserts that the receiver's collector contains a single event, * and that its contents match the given expected level, logger * name, message, and location. The collector's list of retained * events is cleared upon success. * * @param level The expected level. Use null to indicate "don't * care". * @param logger The expected logger name. Use null to indicate * "don't care". * @param message The expected message. Use null to indicate * "don't care". * @param location The expected location. Use null to indicate * "don't care". */ public void assertSingleEvent(Level level, String logger, String message, String location) { assertEventCount(1); assertLastEvent(level, logger, message, location); resetAppender(); } }