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INT-2068 fixed shouldSkipNulls logic

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This commit is contained in:
David Turanski
2011-08-19 18:14:42 -04:00
committed by Mark Fisher
parent c035ce8b03
commit 7921d3f7e6
4 changed files with 114 additions and 43 deletions
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107
spring-integration-core/src/main/java/org/springframework/integration/transformer/HeaderEnricher.java
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@@ -1,5 +1,5 @@
/*
* Copyright 2002-2010 the original author or authors.
* Copyright 2002-2011 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -23,6 +23,8 @@ import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.expression.Expression;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.SpelParserConfiguration;
@@ -36,17 +38,17 @@ import org.springframework.integration.support.MessageBuilder;
/**
* A Transformer that adds statically configured header values to a Message.
* Accepts the boolean 'overwrite' property that specifies whether values
* should be overwritten. By default, any existing header values for
* a given key, will <em>not</em> be replaced.
* Accepts the boolean 'overwrite' property that specifies whether values should
* be overwritten. By default, any existing header values for a given key, will
* <em>not</em> be replaced.
*
* @author Mark Fisher
* @author David Turanski
*/
public class HeaderEnricher implements Transformer {
public class HeaderEnricher implements Transformer, BeanNameAware, InitializingBean {
private static final Log logger = LogFactory.getLog(HeaderEnricher.class);
private final Map<String, ? extends HeaderValueMessageProcessor<?>> headersToAdd;
private volatile MessageProcessor<?> messageProcessor;
@@ -55,6 +57,7 @@ public class HeaderEnricher implements Transformer {
private volatile boolean shouldSkipNulls = true;
private Object beanName;
public HeaderEnricher() {
this(null);
@@ -64,10 +67,10 @@ public class HeaderEnricher implements Transformer {
* Create a HeaderEnricher with the given map of headers.
*/
public HeaderEnricher(Map<String, ? extends HeaderValueMessageProcessor<?>> headersToAdd) {
this.headersToAdd = (headersToAdd != null) ? headersToAdd : new HashMap<String, HeaderValueMessageProcessor<Object>>();
this.headersToAdd = (headersToAdd != null) ? headersToAdd
: new HashMap<String, HeaderValueMessageProcessor<Object>>();
}
public <T> void setMessageProcessor(MessageProcessor<T> messageProcessor) {
this.messageProcessor = messageProcessor;
}
@@ -77,9 +80,11 @@ public class HeaderEnricher implements Transformer {
}
/**
* Specify whether <code>null</code> values, such as might be returned from an expression evaluation,
* should be skipped. The default value is <code>true</code>. Set this to <code>false</false> if a
* <code>null</code> value should trigger <i>removal</i> of the corresponding header instead.
* Specify whether <code>null</code> values, such as might be returned from
* an expression evaluation, should be skipped. The default value is
* <code>true</code>. Set this to <code>false</false> if a
* <code>null</code> value should trigger <i>removal</i> of the
* corresponding header instead.
*/
public void setShouldSkipNulls(boolean shouldSkipNulls) {
this.shouldSkipNulls = shouldSkipNulls;
@@ -92,27 +97,29 @@ public class HeaderEnricher implements Transformer {
for (Map.Entry<String, ? extends HeaderValueMessageProcessor<?>> entry : this.headersToAdd.entrySet()) {
String key = entry.getKey();
HeaderValueMessageProcessor<?> valueProcessor = entry.getValue();
Boolean shouldOverwrite = valueProcessor.isOverwrite();
if (shouldOverwrite == null) {
shouldOverwrite = this.defaultOverwrite;
}
boolean headerDoesNotExist = headerMap.get(key) == null;
/**
* Only evaluate value if necessary
* Only evaluate value expression if necessary
*/
Object value = null;
if (headerMap.get(key) == null || shouldOverwrite || !this.shouldSkipNulls){
value = valueProcessor.processMessage(message);
}
if ((value != null && shouldOverwrite) || headerMap.get(key) == null || (value == null && !this.shouldSkipNulls)) {
headerMap.put(key, value);
if (headerDoesNotExist || shouldOverwrite) {
Object value = valueProcessor.processMessage(message);
if (value != null || !this.shouldSkipNulls) {
headerMap.put(key, value);
}
}
}
return MessageBuilder.withPayload(message.getPayload()).copyHeaders(headerMap).build();
}
return MessageBuilder.withPayload(message.getPayload()).copyHeaders(headerMap).build();
}
catch (Exception e) {
throw new MessagingException(message, "failed to transform message headers", e);
}
throw new MessagingException(message, "failed to transform message headers", e);
}
}
@SuppressWarnings("rawtypes")
@@ -138,17 +145,16 @@ public class HeaderEnricher implements Transformer {
}
}
public static interface HeaderValueMessageProcessor<T> extends MessageProcessor<T> {
Boolean isOverwrite();
}
static abstract class AbstractHeaderValueMessageProcessor<T> implements HeaderValueMessageProcessor<T> {
// null indicates no explicit setting; use header-enricher's 'default-overwrite' value
// null indicates no explicit setting; use header-enricher's
// 'default-overwrite' value
private volatile Boolean overwrite = null;
public void setOverwrite(Boolean overwrite) {
@@ -161,7 +167,6 @@ public class HeaderEnricher implements Transformer {
}
static class StaticHeaderValueMessageProcessor<T> extends AbstractHeaderValueMessageProcessor<T> {
private final T value;
@@ -175,24 +180,27 @@ public class HeaderEnricher implements Transformer {
}
}
static class ExpressionEvaluatingHeaderValueMessageProcessor<T> extends AbstractHeaderValueMessageProcessor<T>
implements BeanFactoryAware {
static class ExpressionEvaluatingHeaderValueMessageProcessor<T> extends AbstractHeaderValueMessageProcessor<T> implements BeanFactoryAware {
private static final ExpressionParser expressionParser = new SpelExpressionParser(new SpelParserConfiguration(true, true));
private static final ExpressionParser expressionParser = new SpelExpressionParser(new SpelParserConfiguration(
true, true));
private final ExpressionEvaluatingMessageProcessor<T> targetProcessor;
/**
* Create a header value processor for the given Expression and the expected type
* of the expression evaluation result. The expectedType may be null if unknown.
* Create a header value processor for the given Expression and the
* expected type of the expression evaluation result. The expectedType
* may be null if unknown.
*/
public ExpressionEvaluatingHeaderValueMessageProcessor(Expression expression, Class<T> expectedType) {
this.targetProcessor = new ExpressionEvaluatingMessageProcessor<T>(expression, expectedType);
}
/**
* Create a header value processor for the given expression string and the expected type
* of the expression evaluation result. The expectedType may be null if unknown.
* Create a header value processor for the given expression string and
* the expected type of the expression evaluation result. The
* expectedType may be null if unknown.
*/
public ExpressionEvaluatingHeaderValueMessageProcessor(String expressionString, Class<T> expectedType) {
Expression expression = expressionParser.parseExpression(expressionString);
@@ -209,6 +217,37 @@ public class HeaderEnricher implements Transformer {
}
/*
* (non-Javadoc)
*
* @see
* org.springframework.beans.factory.BeanNameAware#setBeanName(java.lang
* .String)
*/
public void setBeanName(String beanName) {
this.beanName = beanName;
}
/*
* (non-Javadoc)
*
* @see
* org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
*/
public void afterPropertiesSet() throws Exception {
boolean shouldOverwrite = this.defaultOverwrite;
for (HeaderValueMessageProcessor<?> processor : this.headersToAdd.values()) {
Boolean processerOverwrite = processor.isOverwrite();
if (processerOverwrite != null) {
shouldOverwrite |= processerOverwrite.booleanValue();
}
}
if (!shouldOverwrite && !this.shouldSkipNulls) {
logger.warn(this.beanName
+ " is configured to not overwrite existing headers. 'shouldSkipNulls = false' will have no effect");
}
}
static class MethodInvokingHeaderValueMessageProcessor extends AbstractHeaderValueMessageProcessor<Object> {