A Filter of Java URL Encoding: GetQueryStringEn...

SpringのCharacterEncodingFilterはpostパラメータのみをトランスコードできます.get中国語の文字化けしを解決するには、これを使わなければなりません.

import java.io.IOException; 
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.Filter; 
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log; 
import org.apache.commons.logging.LogFactory;

@SuppressWarnings("unchecked") 
public class GetQueryStringEncoding implements Filter {

private static final Log logger = LogFactory 
.getLog(GetQueryStringEncoding.class);

public void destroy() { 
}

public void doFilter(ServletRequest request, ServletResponse response, 
FilterChain chain) throws IOException, ServletException {
HttpServletRequest httpReq = (HttpServletRequest) request;
HttpServletResponse httpResp = (HttpServletResponse) response;
httpReq.setCharacterEncoding("UTF-8");
httpResp.setCharacterEncoding("UTF-8");

if (httpReq.getQueryString() != null && httpReq.getMethod().equalsIgnoreCase("get")) { 
if (logger.isDebugEnabled())
logger.debug("Intercept Query String: "
+ httpReq.getQueryString());
final Map<String, String[]> parameterMap = new HashMap<String, String[]>();
Enumeration paramNames = httpReq.getParameterNames();
while (paramNames.hasMoreElements()) {
String paramName = (String) paramNames.nextElement();
String[] values = httpReq.getParameterValues(paramName);
for (int i = 0; i < values.length; i++) {
if (values[i] != null)
values[i] = new String(
values[i].getBytes("ISO-8859-1"), "UTF-8");
}
parameterMap.put(paramName, values);
}
chain.doFilter(new HttpServletRequestWrapper(httpReq) {

@Override 
public String getParameter(String name) {
if (parameterMap.get(name) == null)
return null;
return parameterMap.get(name)[0];
}

@Override 
public Map getParameterMap() {
return parameterMap;
}

@Override 
public Enumeration getParameterNames() {
return Collections.enumeration(parameterMap.keySet());
}

@Override 
public String[] getParameterValues(String name) {
return parameterMap.get(name);
}

}, response); 
} else {
chain.doFilter(request, response);
}

} 

public void init(FilterConfig fConfig) throws ServletException { 
if (logger.isInfoEnabled())
logger.info("GetQueryStringEncoding Filter install...");
}

} 

赤い部分は原文ではなく、私が新しく追加したものです.