org.springframework.web.servlet.i18n.LocaleChangeInterceptor Maven / Gradle / Ivy
/*
* Copyright 2002-2021 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.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.servlet.i18n;
import java.util.Locale;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.lang.Nullable;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.support.RequestContextUtils;
/**
* Interceptor that allows for changing the current locale on every request,
* via a configurable request parameter (default parameter name: "locale").
*
* @author Juergen Hoeller
* @author Rossen Stoyanchev
* @since 20.06.2003
* @see org.springframework.web.servlet.LocaleResolver
*/
public class LocaleChangeInterceptor implements HandlerInterceptor {
/**
* Default name of the locale specification parameter: "locale".
*/
public static final String DEFAULT_PARAM_NAME = "locale";
protected final Log logger = LogFactory.getLog(getClass());
private String paramName = DEFAULT_PARAM_NAME;
@Nullable
private String[] httpMethods;
private boolean ignoreInvalidLocale = false;
/**
* Set the name of the parameter that contains a locale specification
* in a locale change request. Default is "locale".
*/
public void setParamName(String paramName) {
this.paramName = paramName;
}
/**
* Return the name of the parameter that contains a locale specification
* in a locale change request.
*/
public String getParamName() {
return this.paramName;
}
/**
* Configure the HTTP method(s) over which the locale can be changed.
* @param httpMethods the methods
* @since 4.2
*/
public void setHttpMethods(@Nullable String... httpMethods) {
this.httpMethods = httpMethods;
}
/**
* Return the configured HTTP methods.
* @since 4.2
*/
@Nullable
public String[] getHttpMethods() {
return this.httpMethods;
}
/**
* Set whether to ignore an invalid value for the locale parameter.
* @since 4.2.2
*/
public void setIgnoreInvalidLocale(boolean ignoreInvalidLocale) {
this.ignoreInvalidLocale = ignoreInvalidLocale;
}
/**
* Return whether to ignore an invalid value for the locale parameter.
* @since 4.2.2
*/
public boolean isIgnoreInvalidLocale() {
return this.ignoreInvalidLocale;
}
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws ServletException {
String newLocale = request.getParameter(getParamName());
if (newLocale != null) {
if (checkHttpMethod(request.getMethod())) {
LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(request);
if (localeResolver == null) {
throw new IllegalStateException(
"No LocaleResolver found: not in a DispatcherServlet request?");
}
try {
localeResolver.setLocale(request, response, parseLocaleValue(newLocale));
}
catch (IllegalArgumentException ex) {
if (isIgnoreInvalidLocale()) {
if (logger.isDebugEnabled()) {
logger.debug("Ignoring invalid locale value [" + newLocale + "]: " + ex.getMessage());
}
}
else {
throw ex;
}
}
}
}
// Proceed in any case.
return true;
}
private boolean checkHttpMethod(String currentMethod) {
String[] configuredMethods = getHttpMethods();
if (ObjectUtils.isEmpty(configuredMethods)) {
return true;
}
for (String configuredMethod : configuredMethods) {
if (configuredMethod.equalsIgnoreCase(currentMethod)) {
return true;
}
}
return false;
}
/**
* Parse the given locale value as coming from a request parameter.
* The default implementation calls {@link StringUtils#parseLocale(String)},
* accepting the {@link Locale#toString} format as well as BCP 47 language tags.
* @param localeValue the locale value to parse
* @return the corresponding {@code Locale} instance
* @since 4.3
*/
@Nullable
protected Locale parseLocaleValue(String localeValue) {
return StringUtils.parseLocale(localeValue);
}
}