/*
* 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 java.util.logging;
import java.text.MessageFormat;
import java.util.ResourceBundle;
/**
* {@code Formatter} objects are used to format {@link LogRecord} objects into a
* string representation. Head and tail strings are sometimes used to wrap a set
* of records. The {@code getHead} and {@code getTail} methods are used for this
* purpose.
*/
public abstract class Formatter {
/**
* Constructs a {@code Formatter} object.
*/
protected Formatter() {
}
/**
* Converts a {@link LogRecord} object into a string representation. The
* resulted string is usually localized and includes the message field of
* the record.
*
* @param r
* the log record to be formatted into a string.
* @return the formatted string.
*/
public abstract String format(LogRecord r);
/**
* Formats a {@code LogRecord} object into a localized string
* representation. This is a convenience method for subclasses of {@code
* Formatter}.
* <p>
* The message string is firstly localized using the {@code ResourceBundle}
* object associated with the supplied {@code LogRecord}.
* <p>
* Notice : if message contains "{0", then java.text.MessageFormat is used.
* Otherwise no formatting is performed.
*
* @param r
* the log record to be formatted.
* @return the string resulted from the formatting.
*/
public String formatMessage(LogRecord r) {
String pattern = r.getMessage();
ResourceBundle rb = null;
// try to localize the message string first
if ((rb = r.getResourceBundle()) != null) {
try {
pattern = rb.getString(pattern);
} catch (Exception e) {
pattern = r.getMessage();
}
}
if (pattern != null) {
Object[] params = r.getParameters();
/*
* if the message contains "{0", use java.text.MessageFormat to
* format the string
*/
if (pattern.indexOf("{0") >= 0 && params != null && params.length > 0) {
try {
pattern = MessageFormat.format(pattern, params);
} catch (IllegalArgumentException e) {
pattern = r.getMessage();
}
}
}
return pattern;
}
/**
* Gets the head string used to wrap a set of log records. This base class
* always returns an empty string.
*
* @param h
* the target handler.
* @return the head string used to wrap a set of log records, empty in this
* implementation.
*/
public String getHead(Handler h) {
return "";
}
/**
* Gets the tail string used to wrap a set of log records. This base class
* always returns the empty string.
*
* @param h
* the target handler.
* @return the tail string used to wrap a set of log records, empty in this
* implementation.
*/
public String getTail(Handler h) {
return "";
}
}