1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache license, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the license for the specific language governing permissions and
15 * limitations under the license.
16 */
17 package org.apache.logging.log4j.core.appender.db.jpa.converter;
18
19 import javax.persistence.AttributeConverter;
20 import javax.persistence.Converter;
21
22 import org.apache.logging.log4j.ThreadContext;
23
24 /**
25 * A JPA 2.1 attribute converter for {@link ThreadContext.ContextStack}s in
26 * {@link org.apache.logging.log4j.core.LogEvent}s. This converter is only capable of converting to {@link String}s. The
27 * {@link #convertToEntityAttribute(String)} method throws an {@link UnsupportedOperationException}. If you need to
28 * support converting to an entity attribute, you should use the {@link ContextStackJsonAttributeConverter} for
29 * conversion both ways.
30 */
31 @Converter(autoApply = false)
32 public class ContextStackAttributeConverter implements AttributeConverter<ThreadContext.ContextStack, String> {
33 @Override
34 public String convertToDatabaseColumn(final ThreadContext.ContextStack contextStack) {
35 StringBuilder builder = new StringBuilder();
36 for (String value : contextStack.asList()) {
37 if (builder.length() > 0) {
38 builder.append('\n');
39 }
40 builder.append(value);
41 }
42 return builder.toString();
43 }
44
45 @Override
46 public ThreadContext.ContextStack convertToEntityAttribute(final String s) {
47 throw new UnsupportedOperationException("Log events can only be persisted, not extracted.");
48 }
49 }