Added MessageTag. Closes #4

src/main/java/net/thauvin/erik/httpstatus/taglibs/MessageTag.java

@@ -0,0 +1,63 @@
+/*
+ * CauseTag.java
+ *
+ * Copyright (c) 2015-2021, Erik C. Thauvin (erik@thauvin.net)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ *   Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ *   Neither the name of this project nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without
+ *   specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package net.thauvin.erik.httpstatus.taglibs;
+
+import net.thauvin.erik.httpstatus.Utils;
+
+import javax.servlet.jsp.JspWriter;
+import javax.servlet.jsp.PageContext;
+import java.io.IOException;
+
+/**
+ * The <code>&lt;hs:message&gt;</code> tag returns the message (if any) for the current error.
+ *
+ * @author <a href="mailto:erik@thauvin.net" target="_blank">Erik C. Thauvin</a>
+ * @created 2021-03-16
+ * @since 1.0.5
+ */
+public class MessageTag extends XmlSupport {
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void doTag() throws IOException {
+        final PageContext pageContext = (PageContext) getJspContext();
+        @SuppressWarnings("PMD.CloseResource")
+        final JspWriter out = pageContext.getOut();
+
+        final String message = (String) pageContext.getRequest().getAttribute(
+                javax.servlet.RequestDispatcher.ERROR_MESSAGE);
+
+        Utils.outWrite(out, message, defaultValue, escapeXml);
+    }
+}