GenericFilterBean lazily initializes its default environment

Alignment with HttpServletBean; consistent use of EnvironmentCapable.

Issue: SPR-15469
This commit is contained in:
Juergen Hoeller
2017-04-27 21:38:30 +02:00
parent 04f0f137e6
commit 1ea54eb2c6
6 changed files with 193 additions and 165 deletions

View File

@@ -1,5 +1,5 @@
/*
* Copyright 2002-2016 the original author or authors.
* Copyright 2002-2017 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.
@@ -38,10 +38,12 @@ import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.EnvironmentAware;
import org.springframework.core.env.Environment;
import org.springframework.core.env.EnvironmentCapable;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceEditor;
import org.springframework.core.io.ResourceLoader;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.context.ServletContextAware;
import org.springframework.web.context.support.ServletContextResourceLoader;
@@ -75,25 +77,21 @@ import org.springframework.web.util.NestedServletException;
* @see #initFilterBean
* @see #doFilter
*/
public abstract class GenericFilterBean implements
Filter, BeanNameAware, EnvironmentAware, ServletContextAware, InitializingBean, DisposableBean {
public abstract class GenericFilterBean implements Filter, BeanNameAware, EnvironmentAware,
EnvironmentCapable, ServletContextAware, InitializingBean, DisposableBean {
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
/**
* Set of required properties (Strings) that must be supplied as
* config parameters to this filter.
*/
private final Set<String> requiredProperties = new HashSet<>();
private String beanName;
private Environment environment;
private ServletContext servletContext;
private FilterConfig filterConfig;
private String beanName;
private Environment environment = new StandardServletEnvironment();
private ServletContext servletContext;
private final Set<String> requiredProperties = new HashSet<>(4);
/**
@@ -104,24 +102,47 @@ public abstract class GenericFilterBean implements
* @see #getFilterName()
*/
@Override
public final void setBeanName(String beanName) {
public void setBeanName(String beanName) {
this.beanName = beanName;
}
/**
* {@inheritDoc}
* Set the {@code Environment} that this filter runs in.
* <p>Any environment set here overrides the {@link StandardServletEnvironment}
* provided by default.
* <p>This {@code Environment} object is used only for resolving placeholders in
* resource paths passed into init-parameters for this filter. If no init-params are
* used, this {@code Environment} can be essentially ignored.
* @see #init(FilterConfig)
*/
@Override
public void setEnvironment(Environment environment) {
this.environment = environment;
}
/**
* Return the {@link Environment} associated with this filter.
* <p>If none specified, a default environment will be initialized via
* {@link #createEnvironment()}.
* @since 4.3.9
*/
@Override
public Environment getEnvironment() {
if (this.environment == null) {
this.environment = createEnvironment();
}
return this.environment;
}
/**
* Create and return a new {@link StandardServletEnvironment}.
* <p>Subclasses may override this in order to configure the environment or
* specialize the environment type returned.
* @since 4.3.9
*/
protected Environment createEnvironment() {
return new StandardServletEnvironment();
}
/**
* Stores the ServletContext that the bean factory runs in.
* <p>Only relevant in case of initialization as bean, to have a ServletContext
@@ -130,7 +151,7 @@ public abstract class GenericFilterBean implements
* @see #getServletContext()
*/
@Override
public final void setServletContext(ServletContext servletContext) {
public void setServletContext(ServletContext servletContext) {
this.servletContext = servletContext;
}
@@ -147,6 +168,16 @@ public abstract class GenericFilterBean implements
initFilterBean();
}
/**
* Subclasses may override this to perform custom filter shutdown.
* <p>Note: This method will be called from standard filter destruction
* as well as filter bean destruction in a Spring application context.
* <p>This default implementation is empty.
*/
@Override
public void destroy() {
}
/**
* Subclasses can invoke this method to specify that this property
@@ -180,19 +211,25 @@ public abstract class GenericFilterBean implements
this.filterConfig = filterConfig;
// Set bean properties from init parameters.
try {
PropertyValues pvs = new FilterConfigPropertyValues(filterConfig, this.requiredProperties);
BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(this);
ResourceLoader resourceLoader = new ServletContextResourceLoader(filterConfig.getServletContext());
bw.registerCustomEditor(Resource.class, new ResourceEditor(resourceLoader, this.environment));
initBeanWrapper(bw);
bw.setPropertyValues(pvs, true);
}
catch (BeansException ex) {
String msg = "Failed to set bean properties on filter '" +
filterConfig.getFilterName() + "': " + ex.getMessage();
logger.error(msg, ex);
throw new NestedServletException(msg, ex);
PropertyValues pvs = new FilterConfigPropertyValues(filterConfig, this.requiredProperties);
if (!pvs.isEmpty()) {
try {
BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(this);
ResourceLoader resourceLoader = new ServletContextResourceLoader(filterConfig.getServletContext());
Environment env = this.environment;
if (env == null) {
env = new StandardServletEnvironment();
}
bw.registerCustomEditor(Resource.class, new ResourceEditor(resourceLoader, env));
initBeanWrapper(bw);
bw.setPropertyValues(pvs, true);
}
catch (BeansException ex) {
String msg = "Failed to set bean properties on filter '" +
filterConfig.getFilterName() + "': " + ex.getMessage();
logger.error(msg, ex);
throw new NestedServletException(msg, ex);
}
}
// Let subclasses do whatever initialization they like.
@@ -214,6 +251,20 @@ public abstract class GenericFilterBean implements
protected void initBeanWrapper(BeanWrapper bw) throws BeansException {
}
/**
* Subclasses may override this to perform custom initialization.
* All bean properties of this filter will have been set before this
* method is invoked.
* <p>Note: This method will be called from standard filter initialization
* as well as filter bean initialization in a Spring application context.
* Filter name and ServletContext will be available in both cases.
* <p>This default implementation is empty.
* @throws ServletException if subclass initialization fails
* @see #getFilterName()
* @see #getServletContext()
*/
protected void initFilterBean() throws ServletException {
}
/**
* Make the FilterConfig of this filter available, if any.
@@ -258,32 +309,6 @@ public abstract class GenericFilterBean implements
}
/**
* Subclasses may override this to perform custom initialization.
* All bean properties of this filter will have been set before this
* method is invoked.
* <p>Note: This method will be called from standard filter initialization
* as well as filter bean initialization in a Spring application context.
* Filter name and ServletContext will be available in both cases.
* <p>This default implementation is empty.
* @throws ServletException if subclass initialization fails
* @see #getFilterName()
* @see #getServletContext()
*/
protected void initFilterBean() throws ServletException {
}
/**
* Subclasses may override this to perform custom filter shutdown.
* <p>Note: This method will be called from standard filter destruction
* as well as filter bean destruction in a Spring application context.
* <p>This default implementation is empty.
*/
@Override
public void destroy() {
}
/**
* PropertyValues implementation created from FilterConfig init parameters.
*/
@@ -298,14 +323,14 @@ public abstract class GenericFilterBean implements
* @throws ServletException if any required properties are missing
*/
public FilterConfigPropertyValues(FilterConfig config, Set<String> requiredProperties)
throws ServletException {
throws ServletException {
Set<String> missingProps = (requiredProperties != null && !requiredProperties.isEmpty()) ?
new HashSet<>(requiredProperties) : null;
Set<String> missingProps = (!CollectionUtils.isEmpty(requiredProperties) ?
new HashSet<>(requiredProperties) : null);
Enumeration<?> en = config.getInitParameterNames();
while (en.hasMoreElements()) {
String property = (String) en.nextElement();
Enumeration<String> paramNames = config.getInitParameterNames();
while (paramNames.hasMoreElements()) {
String property = paramNames.nextElement();
Object value = config.getInitParameter(property);
addPropertyValue(new PropertyValue(property, value));
if (missingProps != null) {
@@ -314,11 +339,11 @@ public abstract class GenericFilterBean implements
}
// Fail if we are still missing properties.
if (missingProps != null && missingProps.size() > 0) {
if (!CollectionUtils.isEmpty(missingProps)) {
throw new ServletException(
"Initialization from FilterConfig for filter '" + config.getFilterName() +
"' failed; the following required properties were missing: " +
StringUtils.collectionToDelimitedString(missingProps, ", "));
"Initialization from FilterConfig for filter '" + config.getFilterName() +
"' failed; the following required properties were missing: " +
StringUtils.collectionToDelimitedString(missingProps, ", "));
}
}
}