#70 Added more defensive null/empty checks to Fail Fast (http://wiki.c2.com/?FailFast)

Author: bbottema

src/main/java/org/simplejavamail/converter/internal/mimemessage/MimeMessageException.java

@@ -2,6 +2,11 @@
 
 import org.simplejavamail.MailException;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import static org.simplejavamail.internal.util.Preconditions.checkNonEmptyArgument;
+
 /**
  * This exception is used to communicate errors during parsing of a {@link javax.mail.internet.MimeMessage}.
  *
@@ -12,7 +17,7 @@ class MimeMessageException extends MailException {
 
 	static final String INVALID_DOMAINKEY = "Error signing MimeMessage with DKIM";
 
-	MimeMessageException(final String message, final Exception cause) {
-		super(message, cause);
+	MimeMessageException(@Nonnull final String message, @Nullable final Exception cause) {
+		super(checkNonEmptyArgument(message, "message"), cause);
 	}
 }

src/main/java/org/simplejavamail/converter/internal/msgparser/OutlookMessageException.java

@@ -2,6 +2,11 @@
 
 import org.simplejavamail.MailException;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import static org.simplejavamail.internal.util.Preconditions.checkNonEmptyArgument;
+
 /**
  * This exception is used to communicate errors during parsing of a MsgParser {@link org.simplejavamail.outlookmessageparser.model.OutlookMessage} of Outlook
  * .msg data.
@@ -13,7 +18,7 @@ class OutlookMessageException extends MailException {
 
 	static final String ERROR_PARSING_OUTLOOK_MSG = "Unable to parse Outlook message";
 
-	OutlookMessageException(@SuppressWarnings("SameParameterValue") final String message, final Exception cause) {
-		super(message, cause);
+	OutlookMessageException(@SuppressWarnings("SameParameterValue") @Nonnull final String message, @Nullable final Exception cause) {
+		super(checkNonEmptyArgument(message, "message"), cause);
 	}
 }

src/main/java/org/simplejavamail/converter/internal/msgparser/OutlookMessageParser.java

@@ -2,32 +2,45 @@
 
 import org.simplejavamail.outlookmessageparser.model.OutlookMessage;
 
+import javax.annotation.Nonnull;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 
+import static org.simplejavamail.internal.util.Preconditions.checkNonEmptyArgument;
+
 /**
  * Helper class that parses {@link OutlookMessage} instances from the {@link org.simplejavamail.outlookmessageparser.OutlookMessageParser} library.
  */
 public final class OutlookMessageParser {
 
-	public static OutlookMessage parseOutlookMsg(final File msgFile) {
+	private OutlookMessageParser() {
+		// util / helper class
+	}
+
+	@Nonnull
+	public static OutlookMessage parseOutlookMsg(@Nonnull final File msgFile) {
+		checkNonEmptyArgument(msgFile, "msgFile");
 		try {
 			return new org.simplejavamail.outlookmessageparser.OutlookMessageParser().parseMsg(msgFile);
 		} catch (final IOException e) {
 			throw new OutlookMessageException(OutlookMessageException.ERROR_PARSING_OUTLOOK_MSG, e);
 		}
 	}
 
-	public static OutlookMessage parseOutlookMsg(final InputStream msgInputStream) {
+	@Nonnull
+	public static OutlookMessage parseOutlookMsg(@Nonnull final InputStream msgInputStream) {
+		checkNonEmptyArgument(msgInputStream, "msgInputStream");
 		try {
 			return new org.simplejavamail.outlookmessageparser.OutlookMessageParser().parseMsg(msgInputStream);
 		} catch (final IOException e) {
 			throw new OutlookMessageException(OutlookMessageException.ERROR_PARSING_OUTLOOK_MSG, e);
 		}
 	}
 
-	public static OutlookMessage parseOutlookMsg(final String msgData) {
+	@Nonnull
+	public static OutlookMessage parseOutlookMsg(@Nonnull final String msgData) {
+		checkNonEmptyArgument(msgData, "msgData");
 		try {
 			return new org.simplejavamail.outlookmessageparser.OutlookMessageParser().parseMsg(msgData);
 		} catch (final IOException e) {