/*
* Copyright 2011 Google Inc. All Rights Reserved.
*
* Licensed 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 com.google.walkaround.util.client.log;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JsonUtils;
import com.google.gwt.xhr.client.XMLHttpRequest;
import com.google.walkaround.util.client.log.Logs.Handler;
import com.google.walkaround.util.client.log.Logs.Level;
/**
* A log handler that reports fatal logs to the server, and tees off warning
* logs to its subclass.
*
* @author danilatos@google.com (Daniel Danilatos)
*/
public class ErrorReportingLogHandler implements Handler {
private boolean firstReport = true;
private final String errorReportUrl;
public ErrorReportingLogHandler(String errorReportUrl) {
this.errorReportUrl = errorReportUrl;
}
@Override
public boolean canReceive() {
return true;
}
@Override
public void receiveEntry(
int num, double timestamp, String stream, Level level, Object[] objects, Throwable t) {
if (level.compareTo(Level.SEVERE) <= 0) {
onSevere(stream);
report(timestamp, stream, level, objects, t);
}
}
/**
* Notifies a subclass of a severe log event on a stream.
*/
protected void onSevere(String stream) {
}
void report(double timestamp, String streamName, Level level, Object[] objects, Throwable t) {
// TODO(danilatos): Use a JsoView to construct and then serialize, rather
// than string builder, unless it's too slow (might even be faster).
StringBuilder sb = new StringBuilder();
sb.append("{\"strongName\" : ");
sb.append(escape(GWT.getPermutationStrongName()));
sb.append(",\"timestamp\" : ");
sb.append("" + (long) timestamp);
sb.append(",\"stream\" : ");
sb.append(escape(streamName));
sb.append(",\"level\" : ");
sb.append(escape(level.name()));
// Stacktrace info of the first exception found, if any
if (t != null) {
sb.append(",\"exception\" : ");
buildExceptionJson(sb, t);
}
sb.append(",\"objects\" : [");
boolean needsComma = false;
for (Object o : objects) {
if (needsComma) {
sb.append(",");
} else {
needsComma = true;
}
sb.append(escape(o != null ? o.toString() : "(null)"));
}
sb.append("]}");
String jsonData = sb.toString();
XMLHttpRequest xhr = XMLHttpRequest.create();
xhr.open("POST", errorReportUrl + "?firstReport=" + firstReport);
firstReport = false;
xhr.send(jsonData);
}
public void buildExceptionJson(StringBuilder sb, Throwable t) {
sb.append("{\"name\" : ");
sb.append(escape(t.getClass().getName()));
sb.append(",\"message\" : ");
sb.append(escape(t.getMessage()));
sb.append(",\"stackTrace\" : [");
boolean needsComma = false;
for (StackTraceElement e : t.getStackTrace()) {
if (needsComma) {
sb.append(",");
} else {
needsComma = true;
}
sb.append(escape(e.getMethodName()));
}
sb.append("]");
if (t.getCause() != null) {
sb.append(",\"cause\" : ");
buildExceptionJson(sb, t.getCause());
}
sb.append("}");
}
String escape(String unescaped) {
// + "" to avoid null
return JsonUtils.escapeValue(unescaped != null ? unescaped : "(null)");
}
}