Simple extension of jakarta.servlet.http.HttpServlet which treats its config parameters (init-param entries within the servlet tag in web.xml) as bean properties.

A handy superclass for any type of servlet. Type conversion of config parameters is automatic, with the corresponding setter method getting invoked with the converted value. It is also possible for subclasses to specify required properties. Parameters without matching bean property setter will simply be ignored.

This servlet leaves request handling to subclasses, inheriting the default behavior of HttpServlet (doGet, doPost, etc).

This generic servlet base class has no dependency on the Spring org.springframework.context.ApplicationContext concept. Simple servlets usually don't load their own context but rather access service beans from the Spring root application context, accessible via the filter's ServletContext (see org.springframework.web.context.support.WebApplicationContextUtils).

The FrameworkServlet class is a more specific servlet base class which loads its own application context. FrameworkServlet serves as direct base class of Spring's full-fledged DispatcherServlet.

Modifier and Type	Class and Description
private static class	HttpServletBean.ServletConfigPropertyValues PropertyValues implementation created from ServletConfig init parameters.

Field Summary

Modifier and Type	Field and Description
private ConfigurableEnvironment	environment
protected final Log	logger Logger available to subclasses.
private final Set<String>	requiredProperties

Inherited from jakarta.servlet.http.HttpServlet:: LEGACY_DO_HEAD

Constructor Summary

Access	Constructor and Description
public	HttpServletBean()

Method Summary

Modifier and Type	Method and Description
protected final void	addRequiredProperty(String name of the required property property) Subclasses can invoke this method to specify that this property (which must match a JavaBean property they expose) is mandatory, and must be supplied as a config parameter.
protected ConfigurableEnvironment	createEnvironment() Create and return a new `StandardServletEnvironment`.
public ConfigurableEnvironment	getEnvironment() Implements org.springframework.core.env.EnvironmentCapable.getEnvironment. Return the `Environment` associated with this servlet.
public String	getServletName() Overrides jakarta.servlet.GenericServlet.getServletName. Implements jakarta.servlet.ServletConfig.getServletName. Overridden method that simply returns `null` when no ServletConfig set yet.
public final void	init() Overrides jakarta.servlet.GenericServlet.init. Map config parameters onto bean properties of this servlet, and invoke subclass initialization.
protected void	initBeanWrapper(BeanWrapper the BeanWrapper to initialize bw) Initialize the BeanWrapper for this HttpServletBean, possibly with custom editors.
protected void	initServletBean() Subclasses may override this to perform custom initialization.
public void	setEnvironment(Environment environment) Implements org.springframework.context.EnvironmentAware.setEnvironment. Set the `Environment` that this servlet runs in. Any environment set here overrides the `StandardServletEnvironment` provided by default.

Inherited from jakarta.servlet.http.HttpServlet:: doDelete doGet doHead doOptions doPost doPut doTrace getLastModified init service service

Field Detail

environment	back to summary
private ConfigurableEnvironment environment Annotations @Nullable

logger	back to summary
protected final Log logger Logger available to subclasses.

requiredProperties	back to summary
private final Set<String> requiredProperties

Constructor Detail

HttpServletBean	back to summary
public HttpServletBean()

Method Detail

addRequiredProperty	back to summary
protected final void addRequiredProperty(String property) Subclasses can invoke this method to specify that this property (which must match a JavaBean property they expose) is mandatory, and must be supplied as a config parameter. This should be called from the constructor of a subclass. This method is only relevant in case of traditional initialization driven by a ServletConfig instance. Parameters property:String name of the required property

addRequiredProperty

back to summary

protected final void addRequiredProperty(String property)

Subclasses can invoke this method to specify that this property (which must match a JavaBean property they expose) is mandatory, and must be supplied as a config parameter. This should be called from the constructor of a subclass.

This method is only relevant in case of traditional initialization driven by a ServletConfig instance.

Parameters

property:String: name of the required property

createEnvironment back to summary

createEnvironment	back to summary
protected ConfigurableEnvironment createEnvironment() Create and return a new `StandardServletEnvironment`. Subclasses may override this in order to configure the environment or specialize the environment type returned.

protected ConfigurableEnvironment createEnvironment()

Create and return a new StandardServletEnvironment.

Subclasses may override this in order to configure the environment or specialize the environment type returned.

getEnvironment back to summary

getEnvironment	back to summary
public ConfigurableEnvironment getEnvironment() Implements org.springframework.core.env.EnvironmentCapable.getEnvironment. Return the `Environment` associated with this servlet. If none specified, a default environment will be initialized via `createEnvironment()`. Annotations @Override

public ConfigurableEnvironment getEnvironment()

Implements org.springframework.core.env.EnvironmentCapable.getEnvironment.

Return the Environment associated with this servlet.

If none specified, a default environment will be initialized via createEnvironment().

Annotations

@Override

getServletName back to summary

getServletName	back to summary
public String getServletName() Overrides jakarta.servlet.GenericServlet.getServletName. Implements jakarta.servlet.ServletConfig.getServletName. Overridden method that simply returns `null` when no ServletConfig set yet. Returns:String Doc from jakarta.servlet.GenericServlet.getServletName. the name of this servlet instance Annotations @Override @Nullable See Also `getServletConfig()`

public String getServletName()

Overrides jakarta.servlet.GenericServlet.getServletName.

Implements jakarta.servlet.ServletConfig.getServletName.

Overridden method that simply returns null when no ServletConfig set yet.

Returns:String

Doc from jakarta.servlet.GenericServlet.getServletName.

the name of this servlet instance

Annotations

@Override
@Nullable

See Also

getServletConfig()

init	back to summary
public final void init() throws ServletException Overrides jakarta.servlet.GenericServlet.init. Map config parameters onto bean properties of this servlet, and invoke subclass initialization. Annotations @Override Exceptions ServletException: if bean properties are invalid (or required properties are missing), or if subclass initialization fails.

init

back to summary

public final void init() throws ServletException

Overrides jakarta.servlet.GenericServlet.init.

Map config parameters onto bean properties of this servlet, and invoke subclass initialization.

Annotations

@Override

Exceptions

ServletException:: if bean properties are invalid (or required properties are missing), or if subclass initialization fails.

initBeanWrapper back to summary

initBeanWrapper	back to summary
protected void initBeanWrapper(BeanWrapper bw) throws BeansException Initialize the BeanWrapper for this HttpServletBean, possibly with custom editors. This default implementation is empty. Parameters bw:BeanWrapper the BeanWrapper to initialize Exceptions BeansException: if thrown by BeanWrapper methods See Also `org.springframework.beans.BeanWrapper#registerCustomEditor`

protected void initBeanWrapper(BeanWrapper bw) throws BeansException

Initialize the BeanWrapper for this HttpServletBean, possibly with custom editors.

This default implementation is empty.

Parameters

bw:BeanWrapper: the BeanWrapper to initialize

Exceptions

BeansException:: if thrown by BeanWrapper methods

initServletBean	back to summary
protected void initServletBean() throws ServletException Subclasses may override this to perform custom initialization. All bean properties of this servlet will have been set before this method is invoked. This default implementation is empty. Exceptions ServletException: if subclass initialization fails

initServletBean

back to summary

protected void initServletBean() throws ServletException

Subclasses may override this to perform custom initialization. All bean properties of this servlet will have been set before this method is invoked.

This default implementation is empty.

Exceptions

ServletException:: if subclass initialization fails

setEnvironment back to summary

setEnvironment	back to summary
public void setEnvironment(Environment environment) Implements org.springframework.context.EnvironmentAware.setEnvironment. Set the `Environment` that this servlet runs in. Any environment set here overrides the `StandardServletEnvironment` provided by default. Annotations @Override Exceptions IllegalArgumentException: if environment is not assignable to `ConfigurableEnvironment`

public void setEnvironment(Environment environment)

Implements org.springframework.context.EnvironmentAware.setEnvironment.

Set the Environment that this servlet runs in.

Any environment set here overrides the StandardServletEnvironment provided by default.

Annotations

@Override

Exceptions

IllegalArgumentException:: if environment is not assignable to ConfigurableEnvironment

org.springframework.web.servlet back to summary

private Class HttpServletBean.ServletConfigPropertyValues

Class Inheritance

extends MutablePropertyValues

java.lang.Object
org.springframework.beans.MutablePropertyValues
org.springframework.web.servlet.HttpServletBean.ServletConfigPropertyValues

PropertyValues implementation created from ServletConfig init parameters.

Constructor Summary

Access	Constructor and Description
public	ServletConfigPropertyValues(ServletConfig the ServletConfig we'll use to take PropertyValues from config, Set<String> set of property names we need, where we can't accept default values requiredProperties) Create new ServletConfigPropertyValues.

Method Summary

Constructor Detail

ServletConfigPropertyValues	back to summary
public ServletConfigPropertyValues(ServletConfig config, Set<String> requiredProperties) throws ServletException Create new ServletConfigPropertyValues. Parameters config:ServletConfig the ServletConfig we'll use to take PropertyValues from requiredProperties:Set<String> set of property names we need, where we can't accept default values Exceptions ServletException: if any required properties are missing

ServletConfigPropertyValues

back to summary

public ServletConfigPropertyValues(ServletConfig config, Set<String> requiredProperties) throws ServletException

Create new ServletConfigPropertyValues.

Parameters

config:ServletConfig: the ServletConfig we'll use to take PropertyValues from
requiredProperties:Set<String>: set of property names we need, where we can't accept default values

Exceptions

ServletException:: if any required properties are missing

public abstract Class HttpServletBean

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private Class HttpServletBean.ServletConfigPropertyValues

Constructor Summary

Method Summary

Constructor Detail