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 java.io.IOException;
20 import java.util.Map;
21
22 import javax.persistence.AttributeConverter;
23 import javax.persistence.Converter;
24 import javax.persistence.PersistenceException;
25
26 import org.apache.logging.log4j.util.Strings;
27
28 import com.fasterxml.jackson.core.type.TypeReference;
29 import com.fasterxml.jackson.databind.ObjectMapper;
30
31 /**
32 * A JPA 2.1 attribute converter for {@link Map Map<String, String>}s in
33 * {@link org.apache.logging.log4j.core.LogEvent}s. This converter is capable of converting both to and from
34 * {@link String}s.
35 *
36 * In addition to other optional dependencies required by the JPA appender, this converter requires the Jackson Data
37 * Processor.
38 */
39 @Converter(autoApply = false)
40 public class ContextMapJsonAttributeConverter implements AttributeConverter<Map<String, String>, String> {
41 static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
42
43 @Override
44 public String convertToDatabaseColumn(final Map<String, String> contextMap) {
45 if (contextMap == null) {
46 return null;
47 }
48
49 try {
50 return OBJECT_MAPPER.writeValueAsString(contextMap);
51 } catch (final IOException e) {
52 throw new PersistenceException("Failed to convert map to JSON string.", e);
53 }
54 }
55
56 @Override
57 public Map<String, String> convertToEntityAttribute(final String s) {
58 if (Strings.isEmpty(s)) {
59 return null;
60 }
61 try {
62 return OBJECT_MAPPER.readValue(s, new TypeReference<Map<String, String>>() { });
63 } catch (final IOException e) {
64 throw new PersistenceException("Failed to convert JSON string to map.", e);
65 }
66 }
67 }