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 javax.persistence.AttributeConverter; 020import javax.persistence.Converter; 021 022import org.apache.logging.log4j.ThreadContext; 023 024/** 025 * A JPA 2.1 attribute converter for 026 * {@link org.apache.logging.log4j.ThreadContext.ContextStack ThreadContext.ContextStack}s in 027 * {@link org.apache.logging.log4j.core.LogEvent}s. This converter is only capable of converting to {@link String}s. The 028 * {@link #convertToEntityAttribute(String)} method throws an {@link UnsupportedOperationException}. If you need to 029 * support converting to an entity attribute, you should use the {@link ContextStackJsonAttributeConverter} for 030 * conversion both ways. 031 */ 032@Converter(autoApply = false) 033public class ContextStackAttributeConverter implements AttributeConverter<ThreadContext.ContextStack, String> { 034 @Override 035 public String convertToDatabaseColumn(final ThreadContext.ContextStack contextStack) { 036 if (contextStack == null) { 037 return null; 038 } 039 040 final StringBuilder builder = new StringBuilder(); 041 for (final String value : contextStack.asList()) { 042 if (builder.length() > 0) { 043 builder.append('\n'); 044 } 045 builder.append(value); 046 } 047 return builder.toString(); 048 } 049 050 @Override 051 public ThreadContext.ContextStack convertToEntityAttribute(final String s) { 052 throw new UnsupportedOperationException("Log events can only be persisted, not extracted."); 053 } 054}