TranslatorFilter.java

package org.test;

import com.liferay.portal.kernel.util.StringPool;
import com.liferay.portal.kernel.util.Validator;
import com.liferay.portal.kernel.util.WebKeys;

import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class TranslatorFilter implements Filter {
	
	private static final Pattern PRE1 = Pattern.compile("/cont-.*[0-9]$");
	private static final Pattern PRE2 = Pattern.compile("/of-.*[0-9]$");
	private static final Pattern PRE3 = Pattern.compile("/oferta-.*[0-9]$");
	private static final String REPALCE = "/-/content/";
	private static final String DETAIL = "/detalle";
	
	@Override
	public void doFilter(ServletRequest req, ServletResponse res,
			FilterChain chain) throws IOException, ServletException {

		String uri = (String) req.getAttribute(WebKeys.INVOKER_FILTER_URI);
		
		Matcher m1 = PRE1.matcher(uri);
		Matcher m2 = PRE2.matcher(uri);
		Matcher m3 = PRE3.matcher(uri);
		
		if (m1.find(0) || m2.find(0) || m3.find(0)) {
			
			String preUrl = StringPool.BLANK;
			int delBlocks = 2;
			
			if (m3.find(0)) { preUrl = DETAIL; }
			if (m1.find(0)) { delBlocks = 1; }
			
			try {
				
				// New uri translation
				
				String[] paths = uri.split(StringPool.SLASH);
				String newUri = StringPool.BLANK;
				
				for (int i = 0; i < paths.length - delBlocks; i++) {
					if (!Validator.isBlank(paths[i])) {
						newUri = newUri + StringPool.SLASH + paths[i]; 
					}
				}
				
				// Extracting article id

				String articleString = paths[paths.length - 1];
				articleString = articleString.substring(
						articleString.indexOf(StringPool.MINUS) + 1, articleString.length());
				Integer articleId = Integer.valueOf(articleString);
				
				// New uri redirection
				
				newUri = newUri + preUrl + REPALCE + articleId;
				
				System.out.println("Pre --> " + uri);
				System.out.println("Post --> " + newUri);
				
				req.getRequestDispatcher(newUri).forward(req, res);
				
			} catch (Exception e) {
				
				e.printStackTrace();
				
				chain.doFilter(req, res);
				
			}
			
		}
		else {
			
			chain.doFilter(req, res);
			
		}
		
	}

	@Override
	public void init(FilterConfig arg0) throws ServletException {}
	
	@Override
	public void destroy() {}

}