Java – Spring Security Authentication using RestTemplate

Here is a solution that works very well with Spring 3.1 and Apache HttpComponents 4.1 I created based various answers on this site and reading the spring RestTempalte source code. I am sharing in hopes of saving others time, I think spring should just have some code like this built in but it does not.

RestClient client = new RestClient();
client.setApplicationPath("someApp");
String url = client.login("theuser", "123456");
UserPortfolio portfolio = client.template().getForObject(client.apiUrl("portfolio"), 
                         UserPortfolio.class);

Below is the Factory class which setups up the HttpComponents context to be the same on every request with the RestTemplate.

public class StatefullHttpComponentsClientHttpRequestFactory extends 
                   HttpComponentsClientHttpRequestFactory
{
    private final HttpContext httpContext;

    public StatefullHttpComponentsClientHttpRequestFactory(HttpClient httpClient, HttpContext httpContext)
    {
        super(httpClient);
        this.httpContext = httpContext;
    }

    @Override
    protected HttpContext createHttpContext(HttpMethod httpMethod, URI uri)
    {
        return this.httpContext;
    }
}

Below is Statefull Rest template that you can use to remember cookies, once you log in with it will remember the JSESSIONID and sent it on subsequent requests.

public class StatefullRestTemplate extends RestTemplate
{
    private final HttpClient httpClient;
    private final CookieStore cookieStore;
    private final HttpContext httpContext;
    private final StatefullHttpComponentsClientHttpRequestFactory statefullHttpComponentsClientHttpRequestFactory;

    public StatefullRestTemplate()
    {
        super();
        httpClient = new DefaultHttpClient();
        cookieStore = new BasicCookieStore();
        httpContext = new BasicHttpContext();
        httpContext.setAttribute(ClientContext.COOKIE_STORE, getCookieStore());
        statefullHttpComponentsClientHttpRequestFactory = new StatefullHttpComponentsClientHttpRequestFactory(httpClient, httpContext);
        super.setRequestFactory(statefullHttpComponentsClientHttpRequestFactory);
    }

    public HttpClient getHttpClient()
    {
        return httpClient;
    }

    public CookieStore getCookieStore()
    {
        return cookieStore;
    }

    public HttpContext getHttpContext()
    {
        return httpContext;
    }

    public StatefullHttpComponentsClientHttpRequestFactory getStatefulHttpClientRequestFactory()
    {
        return statefullHttpComponentsClientHttpRequestFactory;
    }
}

Here is a class to represent a rest client so that you can call into an app secured with spring security.

public class RestClient
{
    private String host = "localhost";
    private String port = "8080";
    private String applicationPath;
    private String apiPath = "api";
    private String loginPath = "j_spring_security_check";
    private String logoutPath = "logout";
    private final String usernameInputFieldName = "j_username";
    private final String passwordInputFieldName = "j_password";
    private final StatefullRestTemplate template = new StatefullRestTemplate();

    /**
     * This method logs into a service by doing an standard http using the configuration in this class.
     * 
     * @param username
     *            the username to log into the application with
     * @param password
     *            the password to log into the application with
     * 
     * @return the url that the login redirects to
     */
    public String login(String username, String password)
    {
        MultiValueMap<String, String> form = new LinkedMultiValueMap<>();
        form.add(usernameInputFieldName, username);
        form.add(passwordInputFieldName, password);
        URI location = this.template.postForLocation(loginUrl(), form);
        return location.toString();
    }

    /**
     * Logout by doing an http get on the logout url
     * 
     * @return result of the get as ResponseEntity
     */
    public ResponseEntity<String> logout()
    {
        return this.template.getForEntity(logoutUrl(), String.class);
    }

    public String applicationUrl(String relativePath)
    {
        return applicationUrl() + "/" + checkNotNull(relativePath);
    }

    public String apiUrl(String relativePath)
    {
        return applicationUrl(apiPath + "/" + checkNotNull(relativePath));
    }

    public StatefullRestTemplate template()
    {
        return template;
    }

    public String serverUrl()
    {
        return "http://" + host + ":" + port;
    }

    public String applicationUrl()
    {
        return serverUrl() + "/" + nullToEmpty(applicationPath);
    }

    public String loginUrl()
    {
        return applicationUrl(loginPath);
    }

    public String logoutUrl()
    {
        return applicationUrl(logoutPath);
    }

    public String apiUrl()
    {
        return applicationUrl(apiPath);
    }

    public void setLogoutPath(String logoutPath)
    {
        this.logoutPath = logoutPath;
    }

    public String getHost()
    {
        return host;
    }

    public void setHost(String host)
    {
        this.host = host;
    }

    public String getPort()
    {
        return port;
    }

    public void setPort(String port)
    {
        this.port = port;
    }

    public String getApplicationPath()
    {
        return applicationPath;
    }

    public void setApplicationPath(String contextPath)
    {
        this.applicationPath = contextPath;
    }

    public String getApiPath()
    {
        return apiPath;
    }

    public void setApiPath(String apiPath)
    {
        this.apiPath = apiPath;
    }

    public String getLoginPath()
    {
        return loginPath;
    }

    public void setLoginPath(String loginPath)
    {
        this.loginPath = loginPath;
    }

    public String getLogoutPath()
    {
        return logoutPath;
    }

    @Override
    public String toString()
    {
        StringBuilder builder = new StringBuilder();
        builder.append("RestClient [\n serverUrl()=");
        builder.append(serverUrl());
        builder.append(", \n applicationUrl()=");
        builder.append(applicationUrl());
        builder.append(", \n loginUrl()=");
        builder.append(loginUrl());
        builder.append(", \n logoutUrl()=");
        builder.append(logoutUrl());
        builder.append(", \n apiUrl()=");
        builder.append(apiUrl());
        builder.append("\n]");
        return builder.toString();
    }
}