code: @Override
      public void setCharacterEncoding(String name) throws UnsupportedEncodingException {
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "setCharacterEncoding: " + name);
          }
          if (null != this.queryParameters || null != this.inReader) {
              // too late, ignore the setting
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "Ignoring encoding, too late");
              }
              return;
          }
          if (connection.getEncodingUtils().isCharsetSupported(name)) {
              this.encoding = name;
          } else {
              throw new UnsupportedEncodingException(name);
          }
      }
docs: /*
  @see javax.servlet.ServletRequest#setCharacterEncoding(java.lang.String)