001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017package org.apache.logging.log4j.core.appender.db.jpa.converter; 018 019import java.io.IOException; 020import java.util.List; 021 022import javax.persistence.AttributeConverter; 023import javax.persistence.Converter; 024import javax.persistence.PersistenceException; 025 026import org.apache.logging.log4j.ThreadContext; 027import org.apache.logging.log4j.spi.DefaultThreadContextStack; 028import org.apache.logging.log4j.util.Strings; 029 030import com.fasterxml.jackson.core.type.TypeReference; 031 032/** 033 * A JPA 2.1 attribute converter for 034 * {@link org.apache.logging.log4j.ThreadContext.ContextStack ThreadContext.ContextStack}s in 035 * {@link org.apache.logging.log4j.core.LogEvent}s. This converter is capable of converting both to and from 036 * {@link String}s. 037 * 038 * In addition to other optional dependencies required by the JPA appender, this converter requires the Jackson Data 039 * Processor. 040 */ 041@Converter(autoApply = false) 042public class ContextStackJsonAttributeConverter implements AttributeConverter<ThreadContext.ContextStack, String> { 043 @Override 044 public String convertToDatabaseColumn(final ThreadContext.ContextStack contextStack) { 045 if (contextStack == null) { 046 return null; 047 } 048 049 try { 050 return ContextMapJsonAttributeConverter.OBJECT_MAPPER.writeValueAsString(contextStack.asList()); 051 } catch (final IOException e) { 052 throw new PersistenceException("Failed to convert stack list to JSON string.", e); 053 } 054 } 055 056 @Override 057 public ThreadContext.ContextStack convertToEntityAttribute(final String s) { 058 if (Strings.isEmpty(s)) { 059 return null; 060 } 061 062 List<String> list; 063 try { 064 list = ContextMapJsonAttributeConverter.OBJECT_MAPPER.readValue(s, new TypeReference<List<String>>() { }); 065 } catch (final IOException e) { 066 throw new PersistenceException("Failed to convert JSON string to list for stack.", e); 067 } 068 069 final DefaultThreadContextStack result = new DefaultThreadContextStack(true); 070 result.addAll(list); 071 return result; 072 } 073}