/**
   * Enables subclasses to override the composition of the password, such as by
   * including additional values and a separator.
   * <p>
   * This might be used for example if a postcode/zipcode was required in addition to
   * the password. A delimiter such as a pipe (|) should be used to separate the
   * password and extended value(s). The <code>AuthenticationDao</code> will need to
   * generate the expected password in a corresponding manner.
   * </p>
   *
   * @param request so that request attributes can be retrieved
   *
   * @return the password that will be presented in the <code>Authentication</code>
   * request token to the <code>AuthenticationManager</code>
   */
  protected String obtainPassword(HttpServletRequest request) {
    return request.getParameter(passwordParameter);
  }

  /**
   * Enables subclasses to override the composition of the username, such as by
   * including additional values and a separator.
   *
   * @param request so that request attributes can be retrieved
   *
   * @return the username that will be presented in the <code>Authentication</code>
   * request token to the <code>AuthenticationManager</code>
   */
  protected String obtainUsername(HttpServletRequest request) {
    return request.getParameter(usernameParameter);
  }

/**
 * AuthenticationFilter that supports rest login(json login) and form login.
 * @author chenhuanming
 */
public class CustomAuthenticationFilter extends UsernamePasswordAuthenticationFilter {

  @Override
  public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {

    //attempt Authentication when Content-Type is json
    if(request.getContentType().equals(MediaType.APPLICATION_JSON_UTF8_VALUE)
        ||request.getContentType().equals(MediaType.APPLICATION_JSON_VALUE)){

      //use jackson to deserialize json
      ObjectMapper mapper = new ObjectMapper();
      UsernamePasswordAuthenticationToken authRequest = null;
      try (InputStream is = request.getInputStream()){
        AuthenticationBean authenticationBean = mapper.readValue(is,AuthenticationBean.class);
        authRequest = new UsernamePasswordAuthenticationToken(
            authenticationBean.getUsername(), authenticationBean.getPassword());
      }catch (IOException e) {
        e.printStackTrace();
        new UsernamePasswordAuthenticationToken(
            "", "");
      }finally {
        setDetails(request, authRequest);
        return this.getAuthenticationManager().authenticate(authRequest);
      }
    }

    //transmit it to UsernamePasswordAuthenticationFilter
    else {
      return super.attemptAuthentication(request, response);
    }
  }
}

@Getter
@Setter
public class AuthenticationBean {
  private String username;
  private String password;
}

@Override
protected void configure(HttpSecurity http) throws Exception {
  http
      .cors().and()
      .antMatcher("/**").authorizeRequests()
      .antMatchers("/", "/login**").permitAll()
      .anyRequest().authenticated()
      //這里必須要寫formLogin()，不然原有的UsernamePasswordAuthenticationFilter不會出現(xiàn)，也就無法配置我們重新的UsernamePasswordAuthenticationFilter
      .and().formLogin().loginPage("/")
      .and().csrf().disable();

  //用重寫的Filter替換掉原有的UsernamePasswordAuthenticationFilter
  http.addFilterAt(customAuthenticationFilter(),
  UsernamePasswordAuthenticationFilter.class);
}

//注冊自定義的UsernamePasswordAuthenticationFilter
@Bean
CustomAuthenticationFilter customAuthenticationFilter() throws Exception {
  CustomAuthenticationFilter filter = new CustomAuthenticationFilter();
  filter.setAuthenticationSuccessHandler(new SuccessHandler());
  filter.setAuthenticationFailureHandler(new FailureHandler());
  filter.setFilterProcessesUrl("/login/self");

  //這句很關鍵，重用WebSecurityConfigurerAdapter配置的AuthenticationManager，不然要自己組裝AuthenticationManager
  filter.setAuthenticationManager(authenticationManagerBean());
  return filter;
}

@Override
@Bean // share AuthenticationManager for web and oauth
public AuthenticationManager authenticationManagerBean() throws Exception {
  return super.authenticationManagerBean();
}