code: @Override
      public String[] getParameterValues(String name) {
          if (this.charset.equalsIgnoreCase(this.originCharset)) {
              return super.getParameterValues(name);
          }
          String[] v = super.getParameterValues(name);
          if (v == null) {
              return null;
          }
          String[] values = new String[v.length];
          try {
              int i = 0;
              for (String value : v) {
                  values[i++] = new String(value.getBytes(this.originCharset),
                          this.charset);
              }
          } catch (UnsupportedEncodingException e) {
              e.printStackTrace();
          }
          return values;
      }
docs: 对参数值进行编码