Class SetCharacterEncodingFilter

java.lang.Object

org.apache.catalina.filters.FilterBase

org.apache.catalina.filters.SetCharacterEncodingFilter

All Implemented Interfaces:

Filter

public class SetCharacterEncodingFilter
extends FilterBase

Example filter that sets the character encoding to be used in parsing the incoming request, either unconditionally or only if the client did not specify a character encoding. Configuration of this filter is based on the following initialization parameters:

• encoding - The character encoding to be configured for this request, either conditionally or unconditionally based on the ignore initialization parameter. This parameter is required, so there is no default.
• ignore - If set to "true", any character encoding specified by the client is ignored, and the value returned by the selectEncoding() method is set. If set to "false, selectEncoding() is called only if the client has not already specified an encoding. By default, this parameter is set to "false".

Although this filter can be used unchanged, it is also easy to subclass it and make the selectEncoding() method more intelligent about what encoding to choose, based on characteristics of the incoming request (such as the values of the Accept-Language and User-Agent headers, or a value stashed in the current user's session.

Field Summary

Fields inherited from class org.apache.catalina.filters.FilterBase

sm

Constructor Summary

Constructors

Constructor	Description
SetCharacterEncodingFilter()

Method Summary

Modifier and Type	Method	Description
void	doFilter(ServletRequest request, ServletResponse response, FilterChain chain)	Select and set (if specified) the character encoding to be used to interpret request parameters for this request.
String	getEncoding()
protected Log	getLogger()
boolean	isIgnore()
protected String	selectEncoding(ServletRequest request)	Select an appropriate character encoding to be used, based on the characteristics of the current request and/or filter initialization parameters.
void	setEncoding(String encoding)
void	setIgnore(boolean ignore)

Methods inherited from class org.apache.catalina.filters.FilterBase

init, isConfigProblemFatal

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface jakarta.servlet.Filter

destroy

Constructor Details

SetCharacterEncodingFilter

public SetCharacterEncodingFilter()

Method Details

setEncoding

public void setEncoding(String encoding)

getEncoding

public String getEncoding()

setIgnore

public void setIgnore(boolean ignore)

isIgnore

public boolean isIgnore()

doFilter

public void doFilter(ServletRequest request,
 ServletResponse response,
 FilterChain chain)
              throws IOException,
ServletException

Select and set (if specified) the character encoding to be used to interpret request parameters for this request.

Parameters:

request - The servlet request we are processing

response - The servlet response we are creating

chain - The filter chain we are processing

Throws:

IOException - if an input/output error occurs

ServletException - if a servlet error occurs

getLogger

protected Log getLogger()

Specified by:

getLogger in class FilterBase

selectEncoding

protected String selectEncoding(ServletRequest request)

Select an appropriate character encoding to be used, based on the characteristics of the current request and/or filter initialization parameters. If no character encoding should be set, return null.

The default implementation unconditionally returns the value configured by the encoding initialization parameter for this filter.

Parameters:

request - The servlet request we are processing

Returns:

the encoding that was configured