/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package freemarker.template;
import java.io.
PrintWriter;
import java.io.
StringWriter;
import java.io.
Writer;
import freemarker.core.
Configurable;
import freemarker.core.
Environment;
import freemarker.core.
StopException;
import freemarker.template.utility.
StringUtil;
/**
* Used for the {@link Configurable#setTemplateExceptionHandler(TemplateExceptionHandler) template_exception_handler}
* configuration setting.
*/
public interface
TemplateExceptionHandler {
/**
* Method called after a {@link TemplateException} was raised inside a template. The exception should be re-thrown
* unless you want to suppress the exception.
*
* <p>Note that you can check with {@link Environment#isInAttemptBlock()} if you are inside a {@code #attempt}
* block, which then will handle this exception and roll back the output generated inside it.
*
* <p>Note that {@link StopException}-s (raised by {@code #stop}) won't be captured here.
*
* <p>Note that you shouldn't log the exception in this method unless you suppress it. If there's a concern that the
* exception might won't be logged after it bubbles up from {@link Template#process(Object, Writer)}, simply
* ensure that {@link Configuration#getLogTemplateExceptions()} is {@code true}.
*
* @param te The exception that occurred; don't forget to re-throw it unless you want to suppress it
* @param env The runtime environment of the template
* @param out This is where the output of the template is written
*/
void
handleTemplateException(
TemplateException te,
Environment env,
Writer out) throws
TemplateException;
/**
* {@link TemplateExceptionHandler} that simply skips the failing instructions, letting the template continue
* executing. It does nothing to handle the event. Note that the exception is still logged, as with all
* other {@link TemplateExceptionHandler}-s.
*/
TemplateExceptionHandler IGNORE_HANDLER = new
TemplateExceptionHandler() {
public void
handleTemplateException(
TemplateException te,
Environment env,
Writer out) {
// Do nothing
}
};
/**
* {@link TemplateExceptionHandler} that simply re-throws the exception; this should be used in most production
* systems.
*/
TemplateExceptionHandler RETHROW_HANDLER = new
TemplateExceptionHandler() {
public void
handleTemplateException(
TemplateException te,
Environment env,
Writer out)
throws
TemplateException {
throw
te;
}
};
/**
* {@link TemplateExceptionHandler} useful when you developing non-HTML templates. This handler
* outputs the stack trace information to the client and then re-throws the exception.
*/
TemplateExceptionHandler DEBUG_HANDLER = new
TemplateExceptionHandler() {
public void
handleTemplateException(
TemplateException te,
Environment env,
Writer out)
throws
TemplateException {
if (!
env.
isInAttemptBlock()) {
PrintWriter pw = (
out instanceof
PrintWriter) ? (
PrintWriter)
out : new
PrintWriter(
out);
pw.
print("FreeMarker template error (DEBUG mode; use RETHROW in production!):\n");
te.
printStackTrace(
pw, false, true, true);
pw.
flush(); // To commit the HTTP response
}
throw
te;
}
};
/**
* {@link TemplateExceptionHandler} useful when you developing HTML templates. This handler
* outputs the stack trace information to the client, formatting it so that it will be usually well readable
* in the browser, and then re-throws the exception.
*/
TemplateExceptionHandler HTML_DEBUG_HANDLER = new
TemplateExceptionHandler() {
public void
handleTemplateException(
TemplateException te,
Environment env,
Writer out)
throws
TemplateException {
if (!
env.
isInAttemptBlock()) {
boolean
externalPw =
out instanceof
PrintWriter;
PrintWriter pw =
externalPw ? (
PrintWriter)
out : new
PrintWriter(
out);
try {
pw.
print("<!-- FREEMARKER ERROR MESSAGE STARTS HERE -->"
+ "<!-- ]]> -->"
+ "<script language=javascript>//\"></script>"
+ "<script language=javascript>//'></script>"
+ "<script language=javascript>//\"></script>"
+ "<script language=javascript>//'></script>"
+ "</title></xmp></script></noscript></style></object>"
+ "</head></pre></table>"
+ "</form></table></table></table></a></u></i></b>"
+ "<div align='left' "
+ "style='background-color:#FFFF7C; "
+ "display:block; border-top:double; padding:4px; margin:0; "
+ "font-family:Arial,sans-serif; ");
pw.
print(
FONT_RESET_CSS);
pw.
print("'>"
+ "<b style='font-size:12px; font-style:normal; font-weight:bold; "
+ "text-decoration:none; text-transform: none;'>FreeMarker template error "
+ " (HTML_DEBUG mode; use RETHROW in production!)</b>"
+ "<pre style='display:block; background: none; border: 0; margin:0; padding: 0;"
+ "font-family:monospace; ");
pw.
print(
FONT_RESET_CSS);
pw.
println("; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; "
+ "white-space: -o-pre-wrap; word-wrap: break-word;'>");
StringWriter stackTraceSW = new
StringWriter();
PrintWriter stackPW = new
PrintWriter(
stackTraceSW);
te.
printStackTrace(
stackPW, false, true, true);
stackPW.
close();
pw.
println();
pw.
println(
StringUtil.
XMLEncNQG(
stackTraceSW.
toString()));
pw.
println("</pre></div></html>");
pw.
flush(); // To commit the HTTP response
} finally {
if (!
externalPw)
pw.
close();
}
} // if (!env.isInAttemptBlock())
throw
te;
}
private static final
String FONT_RESET_CSS =
"color:#A80000; font-size:12px; font-style:normal; font-variant:normal; "
+ "font-weight:normal; text-decoration:none; text-transform: none";
};
}