Here you can find the source of decode(final String content, final String encoding)
public static String decode(final String content, final String encoding)
//package com.java2s; import java.io.UnsupportedEncodingException; import java.net.URLDecoder; public class Main { /** Default charsets */ public static final String DEFAULT_CONTENT_CHARSET = "ISO-8859-1"; public static String decode(final String content, final String encoding) { try {//from w ww. j a v a2 s. c om return URLDecoder.decode(content, encoding != null ? encoding : DEFAULT_CONTENT_CHARSET); } catch (UnsupportedEncodingException problem) { throw new IllegalArgumentException(problem); } } }