Category Archives: Java

How to use Spring Security in web application – Part VIII

In this post, we will show how to use Spring Boot Security to login, authorization based on user role, log out, and error handling.

We will be discussing the following use case

  1. A user accesses a home page for an application.
  2. A user enters credentials
  3. If correct credentials, we create a session and verifies the user role. User with USER role sees the user profile page. User with ADMIN role sees the list of users page.
  4. Incorrect credentials, the user will see the login screen once again to enter credentials.
  5. A user clicks on logout, the session is deleted and the user is redirected to the login page.
  6. If a user (of any role) tries to login after logout, the user should be redirected to the appropriate page
  7. In a scenario where a user is neither USER nor ADMIN, he is redirected to the error page
  8. Handling of CSRF token

To completely understand this post, make sure you have gone through my other posts on the Spring Boot series.

  1. Spring Boot REST CRUD API
  2. Swagger Documentation
  3. User Interface using AngularJS

 

Database changes

Since this post involves authorization for users, we have to do some database changes. We will add a couple of tables and respective model classes in our REST API modification.

  • Table role
  • Table user_role

create table role (id int(11) auto_increment primary key not null, role varchar(255) )

create table user_role (user_id int(11) primary key not null, role_id int(11) primary key not null))

user_role the table helps to maintain a many-to-many relationship between the user and role table. We will have only two roles for demo purposes, USER and ADMIN.

Another change we have done in table user is that we have added a field called password_hash to store password set by user/administrator for a user to login. We will be storing a hash password value of the original password that the user will set.

Dependencies

Since we will be using Spring-security for authentication and authorization purposes, we will add the dependency for spring security as follows:

<dependency>   

<groupId>org.springframework.boot</groupId>   

<artifactId>spring-boot-starter-security</artifactId>

</dependency>

Controllers and Web Layer

Other than those changes mentioned, we will demonstrate this post in top-down fashion rather than bottom-up fashion.

So for the web layer, we will define a new controller LoginController and modify our existing MainController.

package com.betterjavacode.benefits.controller;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.betterjavacode.benefits.entities.User;
import com.betterjavacode.benefits.interfaces.UserManager;

/**
*
* @author Yogesh Mali
*
*/
@Controller
public class LoginController {

public static final Logger LOGGER = LogManager.getLogger(LoginController.class);

@Autowired
UserManager userManager;

/**
*
* @param model
* @return
*/
@RequestMapping(value = "/user", method = RequestMethod.GET)
public String userpage(Model model) 
{
  LOGGER.info(" Enter >> userpage() ");
  Authentication auth = SecurityContextHolder.getContext().getAuthentication();
  String name = auth.getName();
  User user = userManager.findUserByEmail(name);
  model.addAttribute("name", user.getFirstname());
  model.addAttribute("userid", user.getId());
  LOGGER.info(" Exit << userpage() ");
  return "user";
}

/**
*
* @return
*/
@RequestMapping(value = { "/login" })
public String login() {
  return "login";
}

/**
*
* @return
*/
@RequestMapping(value = "/403", method = RequestMethod.GET)
public String Error403() {
  return "403";
}
}

As shown in this controller, we have defined a user page, a login page, and an error page (403). A user with the role of either USER or ADMIN or both can access a user page which shows that logged in user’s profile.

Every user irrespective of roles will see the login page for authentication. If there are any errors during authentication or authorization, the user will see an error page displaying access denied page (403).

Source code for login page is as below:

<!DOCTYPE html><!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org">
<head> <title>Benefits Application</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" /> <link rel="stylesheet" type="text/css" th:href="@{/css/login.css}" />  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script></head>
<body>
<div class="container"> <form th:action="@{/login}" method="POST" class="form-signin">
<h3 class="form-signin-heading" th:text="Welcome"></h3>
<input type="text" id="email" name="username"  th:placeholder="Email" class="form-control" style="width:350px"/>
<input type="password"  th:placeholder="Password" id="password" name="password" class="form-control" style="width:350px"/>
<div align="center" th:if="${param.error}">
<p style="font-size: 20; color: #FF1C19;">Email or Password invalid, please verify</p>

</div>
<button class="btn btn-lg btn-primary btn-block" name="Submit" value="Login" type="Submit" th:text="Login" style="width:350px"></button> </form></div>
</body></html>

This login page shows a simple form to input username (email) and password and process that authentication using spring-security database authentication method.

@RequestMapping(value = "/home", method = RequestMethod.GET)
public String homepage(Model model) 
{
  LOGGER.info(" Enter >> homepage() ");
  Authentication auth = SecurityContextHolder.getContext().getAuthentication();
  String name = auth.getName();
  User user = userManager.findUserByEmail(name);
  model.addAttribute("name", user.getFirstname());
  LOGGER.info(" Exit << homepage() ");
  return "index";
}

Changes in MainController are about an authenticated user and passing that user’s first name to model to display in HTML page. UserManager in the service layer has been enhanced to return a user based on username (which is email). We have also added an email to be unique as a constraint in the database.

User page for a user with role USER is nothing but a user profile information that he can edit and update any time.

<html ng-app="benefitApp"><html ng-app="benefitApp"><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<title>Benefit Application</title><script>document.write('<base href="' + document.location + '" />');</script> <link rel="stylesheet" href="/css/bootstrap.css" /><script src="https://code.angularjs.org/1.6.1/angular.js"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.6.1/angular-route.js"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.6.1/angular-resource.js"></script><script type="text/javascript" src="./js/app.js"></script></head><body ng-controller="UserCtrl">Hello
<p th:text="${name}"></p>

<div>
<ul class="menu">
<li><a th:href="@{'userProfile/' + ${userid}}">Profile</a></li>
</ul>
<div ng-view="ng-view"></div>
</div>
<div class="input-group">
<div class="controls">    <a ng-click="logout()" class="btn btn-small">Logout</a></div>
</div>
</body></html>

Authentication

Now we have the application ready with all the required backend details for adding the authentication part. Remember we are using spring-security for authentication and authorization of an application.

package com.betterjavacode.benefits;

import javax.sql.DataSource;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.security.SecurityProperties;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.builders.WebSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;

@Configuration
@ComponentScan("com.betterjavacode.benefits.services")
@EnableWebSecurity
@Order(SecurityProperties.ACCESS_OVERRIDE_ORDER)
public class SecurityConfig extends WebSecurityConfigurerAdapter {

public static final Logger LOGGER = LogManager.getLogger(SecurityConfig.class);

@Autowired
private SimpleAuthenticationSuccessHandler loginSuccess;

@Autowired
private LogoutSuccess logoutSuccess;

@Autowired
private BCryptPasswordEncoder bCryptPasswordEncoder;

@Autowired
private DataSource dataSource;

@Value("${spring.queries.users-query}")
private String usersQuery;

@Value("${spring.queries.roles-query}")
private String rolesQuery;

@Autowired
protected void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
LOGGER.info(" Enter >> configureGlobal() ");
auth.jdbcAuthentication()
.usersByUsernameQuery("select email,password_hash,enabled from user where email=?")
.authoritiesByUsernameQuery("select u.email,r.role from user u inner join user_role ur on(u.id=ur.user_id) inner join role r on(r.id=ur.role_id) where u.email=?")
.dataSource(dataSource)
.passwordEncoder(bCryptPasswordEncoder);
LOGGER.info(" Exit << configureGlobal() ");
}

/**
* Handle Login - Authentication and Redirection
*/
@Override
protected void configure(HttpSecurity http) throws Exception {
http.csrf()
.disable()
.authorizeRequests()
.antMatchers("/home")
.hasAuthority("ADMIN")
.antMatchers("/user")
.hasAnyAuthority("USER", "ADMIN")
.and()
.formLogin()
.loginPage("/login")
.successHandler(loginSuccess)
.permitAll()
.and()
.logout()
.logoutSuccessHandler(logoutSuccess)
.deleteCookies("JSESSIONID")
.invalidateHttpSession(false)
.permitAll()
.and()
.exceptionHandling()
.accessDeniedPage("/403");

}

/**
* Exclude resources from user-access
*/
@Override
public void configure(WebSecurity web) throws Exception {
web.ignoring()
.antMatchers("/resources/**", "/static/**", "/css/**", "/js/**", "/images/**");
}
}

What’s happening in this code?

  • When a user with role ADMIN or USER calls either /home or /user pages respectively, the user will need to log in.
  • Once the user inputs credentials, validation of credentials happens against the JDBC database authentication mechanism provided by spring-security.
  • If a user of the role USER tries to access the ADMIN home page, the user sees an error 403 page. Authentication Success Handler handles the redirection strategy.
  • If the user clicks the LOGOUT button on the page he is on, the session gets deleted and the user logs out of the application. The user will see the login page. All the cookies will be deleted. Logout Success Handler handles the redirection.

 

Changes in AngularJS User Interface Controller

As shown in user.html page, once the user with role USER is logged in, he sees URL for his profile information. If a user clicks this URL, the user sees his or her profile information. This page has a controller called UserCtrl which basically handles the logout on this initial page. User Profile is shown on userprofile.html page which has singleusercontroller. This angular js controller handles updating user profile information or logout. The github repository contains the rest of the code.

Handling CSRF Token

There are two ways we can handle Cross-Site Request Forgery token in the Spring application. The first way is by disabling this token generation. This is not a recommended approach as this put your application to possible CSRF security attacks for hackers. If you are just doing this for demo purposes, you can disable this in SecurityConfig.java by calling http.csrf().disable().

As Spring points out, a request coming through browsers should contain CSRF Protection.

We will be using spring security to handle CSRF token on the server-side rather than on the client-side.  So every request that comes to the server, we will add a CSRF token and then verified. Angular JS verifies the cookie for the CSRF token before a user can post any request.

Add a CSRF Filter Class

We will add a filter that will handle setting of CSRF token in a cookie. Angular JS expects a cookie name to be as XSRF-TOKEN. This class will look like below:

public class CSRFHeaderFilter extends OncePerRequestFilter {

@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException 
{
  CsrfToken csrf = (CsrfToken) request.getAttribute(CsrfToken.class.getName());
  if (csrf != null) 
  {
    Cookie cookie = WebUtils.getCookie(request, "XSRF-TOKEN");
    String token = csrf.getToken();
    if (cookie == null || token != null && !token.equals(cookie.getValue())) 
    {
      cookie = new Cookie("XSRF-TOKEN", token);
      cookie.setPath("/");
      response.addCookie(cookie);
    }
  }
  filterChain.doFilter(request, response);
}

}

Now we will enable csrf token in SecurityConfig as shown below

.and()
.csrf()
.csrfTokenRepository(csrfTokenRepository())
.and()
.addFilterAfter(new CSRFHeaderFilter(), CsrfFilter.class);

What is csrfTokenRepository?

We tell spring-security to expect CSRF token in the format that Angular wants to send it back , a header called X-XSRF-TOKEN instead of default X-CSRF-TOKEN. With these changes, we don’t have to do anything on client side.

private CsrfTokenRepository csrfTokenRepository() 
{
  HttpSessionCsrfTokenRepository repository = new HttpSessionCsrfTokenRepository();
  repository.setHeaderName("X-XSRF-TOKEN");
  return repository;
}

Demo

In this post, we showed how to use spring security for authentication and authorization. Now we will show how to run the application. Once the application is built and run from eclipse, access the page https://localhost:8443/home , we will see below screen:

Using Spring Security in web application - login screenIt will be the same screen if you access https://localhost:8443/user. Now if we enter credentials of an admin user, we will see below screen:

User screen will be as below:

If you click logout, it will log the user out and show login screen again. In this way, we showed how we can use spring security for authentication and authorization. Code for this is available at Github repository.

References

  1. Spring Boot Security
  2. Login Page Angular JS and Spring Security

 

Microservices – A Primer

In this post, I cover a primer about microservices.

What is Microservices? A Primer about Microservices

Wikipedia definition says

Microservices is a variant of the service-oriented architecture (SOA) architectural style that structures an application as a collection of loosely coupled services.

Firstly, there is no official definition of Microservices by industry standards. It’s a recent phenomenon in the software industry to architect the new software which should be lightweight, easier to deploy, and scale, easier to refactor individually, and could work independently.

However, to understand in detail, you can definitely read Martin Fowler’s Microservices or Chris Richardson’s Microservices.

Secondly, microservices are small services that can run independently but can also easily communicate with other services.

Microservice Architecture vs Monolithic Architecture

In a traditional monolithic architecture style, there is a single application with a single code base. An application contains a number of modules that are interrelated and can have external dependencies. It’s a multi-tier enterprise application and has been used to build software for long.

Above all, the microservice architecture style was born out of a need to build an application that could easily be supported for mobile applications. The older style was not easy to support for mobile and new generation way to the handling of data. Any large enterprise application can be easily built using the microservices architecture style. A famous example is NETFLIX.

How to identify the Microservice Architecture Pattern?

A simple ground rule of the microservice architecture pattern is to build a standalone service that can be run without depending on any other service. In other words, a large application can have more than one service talking to each other, communicating with their own databases, but still performing the business logic. Databases are used to ensure loose coupling of services.

For instance, a large enterprise e-commerce application can consist of the following services

  1. Backend service REST API to manage data
    1. Account Service
    2. Shipment Service
    3. Inventory Service
  2. Runtime service to handle runtime and backend data to process business logic
  3. Logging service
  4. Error Handling service
  5. Session service

Additionally, UI for the e-commerce application can be built independently to use backend services to show/edit data.

By standards, there are few rules to identify microservices patterns

  1. Decomposition by business capability
  2. Database per service pattern
  3. API gateway pattern
  4. Client-side discovery and Server-side discovery

Pros and Cons of Microservices

Pros

  1. Deployability – Easier to deploy and one can deploy them independently, without affecting other services.
  2. Reliability – A fault in the service can only bring down that service. Depending on the handling of the fault in the application, the rest of the application can still continue to work.
  3. Scalability – Similarly, the scaling of each microservice will depend on requirements using clusters and grids.
  4. Availability – Dispatching the patch or newer version of service requires less downtime compared to regular monolithic applications.
  5. Management – Easier to manage
  6. Design and Development – Each service helps the developer to manage the service easily without worrying about other services.

Cons

  1. Performance – All services involved in the application have to communicate with each other over the network and that could hamper the performance.
  2. Testability – Automated tests are harder to manage and run.
  3. Memory usage – Possible duplicate data across services and a lot of duplication in the cache.

References

In conclusion, I covered a primer about microservices. If you want to read more about Microservices at following links:

  1. Microservices by Chris Richardson
  2. Microservices by Martin Fowler
  3. Stackoverflow post about microservices

Lastly, if you enjoyed this post, subscribe to my blog.

 

Handle uncaught exceptions in a Spring-Boot REST API – Part VI

Many times, we have seen exception thrown on your web page and all the stack trace of the exception. A non-technical user will not be able to understand most of the time. Also stack trace is not the best option when we can show the same exception error in nice JSON format with the root cause. In this post, we will show how to handle uncaught exceptions from our previous Spring REST API we built here.

This particular feature will show how to handle most HTTP 500 errors which happen because of server side issues. Any errors with request or client side, those are HTTP 400 errors and they have been handled in previous post Error Handling in Spring Boot Rest API.

Problem of uncaught exceptions

Firstly, what happens when there is a database connection issue? OR Columns in your REST API are different from specified in database tables? Your API will throw a 500 error and if you don’t have any mechanism, this will display error in an html format which will not give much information to user or developer to resolve the issue. Showing such stack trace on web page to end user is a bad example from programming perspective.

Solution

JAX-RS provides a way to handle uncaught exceptions. This can be done by my implementing an interface for ExtendedExceptionMapper. Basically this is a contract for a provider that takes java exceptions and maps them to a response object which can be transformed into a JSON. This can be implemented as below:

package com.betterjavacode.benefits.utilities;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.glassfish.jersey.spi.ExtendedExceptionMapper;

@Provider
public class UncaughtExceptionMapper implements ExtendedExceptionMapper<Throwable> 
{

   private static final Logger LOGGER = LogManager.getLogger(UncaughtExceptionMapper.class);

   @Override
   public Response toResponse(Throwable exception) 
   {
     LOGGER.info("Enter >> toResponse ");
     LOGGER.debug("Exception Caught: " + exception.getMessage());
     LOGGER.info("Exit << toResponse");
     return Response.status(Status.BAD_REQUEST)
       .entity(exception.getMessage())
       .build();
   }

   @Override
   public boolean isMappable(Throwable arg0) 
   {
     return !(arg0 instanceof WebApplicationException);
   }

}

Basically this implementation shows a class `UncaughtExceptionMapper` implementing an interface `ExtendedExceptionMapper` which provides a way to map all exceptions which are not of type WebApplicationException (Most HTTP 400 errors are WebApplicationExceptions). toResponse method will help to log all the exceptions and convert exceptions into a Response object.

Conclusion

In conclusion, we showed how to map all unhandled exceptions into JSON format for a nice response. The code for this post is available at github repository.

Producing and Consuming SOAP Webservice with Spring Boot – Part V

In this post, we will describe how to create a SOAP webservice from our existing Spring Boot REST API. In the last few posts, we have covered the following

  1. Spring Boot REST CRUD API – Part I
  2. Swagger Documentation for Spring Boot REST API – Part II
  3. Error Handling and logging in Spring Boot REST API – Part III
  4. Consuming RESTful Webservice – Part IV

This SOAP webservice will provide us user data from the database which is we have connected through Spring-data in Spring REST API.

1. Requirements

  1. Eclipse Mars2
  2. Maven 3.1 and above
  3. Spring 1.4 and above
  4. Java 7
  5. Tomcat 8

2. SOAP Web Service

We will use our existing Spring Boot REST API to build an application that will act as a SOAP web service to provide users data. For a given user id, web service will return user data.

Let’s create a schema file in src/main/resources directory and maven will create java classes based on this schema file.


<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:tns="https://betterjavacode.com/benefits/soap" targetNamespace="https://betterjavacode.com/benefits/soap" elementFormDefault="qualified">
	<xs:element name="getUserRequest">
		<xs:complexType>
			<xs:sequence>
				<xs:element name="id" type="xs:int"/>
			</xs:sequence>
		</xs:complexType>
	</xs:element>
	<xs:element name="getUserResponse">
		<xs:complexType>
			<xs:sequence>
				<xs:element name="user" type="tns:user"/>
			</xs:sequence>
		</xs:complexType>
	</xs:element>
	<xs:complexType name="user">
		<xs:sequence>
			<xs:element name="id" type="xs:int"/>
			<xs:element name="firstname" type="xs:string"/>
			<xs:element name="middlename" type="xs:string"/>
			<xs:element name="lastname" type="xs:string"/>
			<xs:element name="username" type="xs:string"/>
			<xs:element name="createdate" type="xs:date"/>
			<xs:element name="jobtitle" type="xs:string"/>
			<xs:element name="email" type="xs:string"/>
		</xs:sequence>
	</xs:complexType>
</xs:schema>

 

3. Update Maven dependencies

Now to generate classes from schema, we have to make sure we have all the right dependencies in our pom.xml. We will also add spring boot service dependency to create a SOAP web service.


<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.betterjavacode</groupId>
 <artifactId>Benefits</artifactId>
 <packaging>war</packaging>
 <version>0.0.1-SNAPSHOT</version>
 <name>Benefits Maven Webapp</name>
 <url>http://maven.apache.org</url>
 <parent>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-parent</artifactId>
 <version>1.4.2.RELEASE</version>
 </parent>
 <dependencies>
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-web</artifactId>
 </dependency>
<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-data-jpa</artifactId>
 </dependency>
 <dependency>
 <groupId>mysql</groupId>
 <artifactId>mysql-connector-java</artifactId>
 <scope>runtime</scope>
 </dependency>
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-jdbc</artifactId>
 </dependency>
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-test</artifactId>
 </dependency>
 <dependency>
 <groupId>org.slf4j</groupId>
 <artifactId>slf4j-api</artifactId>
 </dependency>
 <dependency>
 <groupId>io.swagger</groupId>
 <artifactId>swagger-jersey2-jaxrs</artifactId>
 <version>1.5.12</version>
 </dependency>
 <dependency>
 <groupId>io.springfox</groupId>
 <artifactId>springfox-swagger2</artifactId>
 <version>2.6.1</version>
 <scope>compile</scope>
 </dependency>
 <dependency>
 <groupId>io.springfox</groupId>
 <artifactId>springfox-swagger-ui</artifactId>
 <version>2.6.1</version>
 <scope>compile</scope>
 </dependency>
 <dependency>
 <groupId>org.apache.logging.log4j</groupId>
 <artifactId>log4j-api</artifactId>
 </dependency>
 <dependency>
 <groupId>org.apache.logging.log4j</groupId>
 <artifactId>log4j-core</artifactId>
 </dependency>
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-web-services</artifactId>
 </dependency>
 <dependency>
 <groupId>wsdl4j</groupId>
 <artifactId>wsdl4j</artifactId>
 </dependency>
 <dependency>
 <groupId>javax.xml.bind</groupId>
 <artifactId>jaxb-api</artifactId>
 <version>2.1</version>
 </dependency>
 <dependency>
 <groupId>junit</groupId>
 <artifactId>junit</artifactId>
 <scope>test</scope>
 </dependency>
 </dependencies>
 <build>
 <plugins>
 <plugin>
 <artifactId>maven-compiler-plugin</artifactId>
 <version>3.3</version>
 <configuration>
 <source>1.8</source>
 <target>1.8</target>
 </configuration>
 </plugin>
 <plugin>
 <artifactId>maven-war-plugin</artifactId>
 <version>2.6</version>
 <configuration>
 <warSourceDirectory>WebContent</warSourceDirectory>
 <failOnMissingWebXml>false</failOnMissingWebXml>
 </configuration>
 </plugin>
 <plugin>
 <groupId>org.codehaus.mojo</groupId>
 <artifactId>jaxb2-maven-plugin</artifactId>
 <version>1.6</version>
 <executions>
 <execution>
 <id>xjc</id>
 <goals>
 <goal>xjc</goal>
 </goals>
 </execution>
 </executions>
 <configuration>
 <schemaDirectory>${project.basedir}/src/main/resources/</schemaDirectory>
 <outputDirectory>${project.basedir}/src/main/java</outputDirectory>
 <clearOutputDir>false</clearOutputDir>
 <schemaLanguage>WSDL</schemaLanguage>
 <generatePackage>com.betterjavacode.benefits.soap</generatePackage>
 <forceRegenerate>true</forceRegenerate>
 <scehmas>
 <schema>
 <url>http://localhost:8080/benefits/endpoints/users.wsdl</url>
 </schema>
 </scehmas>
 </configuration>
 </plugin>
 </plugins>
 <finalName>Benefits</finalName>
 </build>
 </project>

 

If we run the project with maven build now, the plugin jaxb2-maven-plugin will generate classes under com.betterjavacode.benefits.soap directory. It will also enable our wsdl SOAP url for users. This will generate following java objects

  • GetUserRequest
  • GetUserResponse
  • ObjectFactory
  • package-info
  • User

4. Defining the service

Next, we will define an interface for our service. This will look like below


package com.betterjavacode.benefits.services;

public interface UserAccountService
{
    public com.betterjavacode.benefits.soap.user.getUserDetails(int id);
}

Implementation of this service will be mapping out entity class User to generated class for soap service User. Using the id as a key to get user data from repository, we will map to soap service user. For post purposes, we will not show the implementation of this interface.

5. Creating the Service Endpoint

What is a service endpoint? When a SOAP request for defined URL is handled by Spring servlet, Spring servlet redirects that request to service endpoint. Service endpoint then processes that request to create a response. Our spring-boot-starter-web-services dependency will bring all the necessary classes for annotation purposes.


package com.betterjavacode.benefits.services.endpoints; 

import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.ws.server.endpoint.annotation.Endpoint; 
import org.springframework.ws.server.endpoint.annotation.PayloadRoot; 
import org.springframework.ws.server.endpoint.annotation.RequestPayload; 
import org.springframework.ws.server.endpoint.annotation.ResponsePayload; 
import com.betterjavacode.benefits.services.UserAccountService; 
import com.betterjavacode.benefits.soap.GetUserRequest; 
import com.betterjavacode.benefits.soap.GetUserResponse; 
import com.betterjavacode.benefits.soap.User; 

@Endpoint 
public class UserAccountServiceEndpoint 
{ 
  // private static final String TARGET_NAMESPACE ="http://com/betterjavacode/benefits/webservices/useraccountservice";  
  private static final String TARGET_NAMESPACE =   "https://betterjavacode.com/benefits/soap"; 
  @Autowired private UserAccountService userAccountService; 
  @PayloadRoot(localPart = "getUserRequest", namespace = TARGET_NAMESPACE) 

  public @ResponsePayload GetUserResponse getUserRequest(@RequestPayload    GetUserRequest request) 
  {  
     GetUserResponse response = new GetUserResponse(); 
     User user = userAccountService.getUserDetails(request.getId()); 
     response.setUser(user); 
     return response; 
   } 
}

@Endpoint annotation allows the class to be defined as service endpoint and included in @Component annotation for scanning. Make sure the namespace defined in this class matches with XSD schema definition. Otherwise, you can run into error for “No Endpoint defined for“.

6. Configuration

Next, we will configure our configuration class to generate wsdl endpoint. This configuration class will be annotated by @EnableWs to provide web service configuration.


package com.betterjavacode.benefits;

import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.ws.config.annotation.EnableWs;
import org.springframework.ws.config.annotation.WsConfigurerAdapter;
import org.springframework.ws.transport.http.MessageDispatcherServlet;
import org.springframework.ws.wsdl.wsdl11.DefaultWsdl11Definition;
import org.springframework.xml.xsd.SimpleXsdSchema;
import org.springframework.xml.xsd.XsdSchema;

@Configuration
@EnableWs
@ComponentScan("com.betterjavacode")
public class AppConfig extends WsConfigurerAdapter
{

    @Bean
	public ServletRegistrationBean messageDispatcherServlet(ApplicationContext applicationContext)
	{
		MessageDispatcherServlet servlet = new MessageDispatcherServlet();
		servlet.setApplicationContext(applicationContext);
		return new ServletRegistrationBean(servlet,"/benefits/endpoints/*");
	}

	@Bean(name="users")
	public DefaultWsdl11Definition defaultWsdl11Definition(XsdSchema usersSchema)
	{
		DefaultWsdl11Definition wsdl11definition = new DefaultWsdl11Definition();
		wsdl11definition.setPortTypeName("UserAccountService");
		wsdl11definition.setLocationUri("/endpoints");
		wsdl11definition.setTargetNamespace("http://com/betterjavacode/benefits/webservices/useraccountservice");
		wsdl11definition.setSchema(usersSchema);
		return wsdl11definition;
	}

	@Bean
	public XsdSchema usersSchema()
	{
		return new SimpleXsdSchema(new ClassPathResource("employees.xsd"));
	}
}

Few important points about this configuration class are

  • MessageDispatcherServlet is a required servlet to dispatch web service messages. We set this servlet with a bean to handle the URL from which request will be coming.
  • DefaultWsdl11Definition creates SOAP for the given XSD schema
  • XsdSchema provides an abstraction for our users XSD schema

7. Running the SOAP Webservice

Now build our project with maven. Run the spring boot application through eclipse to start the embedded tomcat server. Once the tomcat server starts, if we access url http://localhost:8080/benefits/endpoints/users.wsdl

Output in the browser will be as below

Here we showed how to create a simple SOAP webservice which we have combined with Spring Boot REST API service. We can also test this SOAP webservice using Soap UI, as shown in below screenshot

8. Consuming the SOAP web service

In previous steps, we showed how to produce a SOAP web service, now we will show how to consume this SOAP web service programmatically.

8.1 Create a client class

Under package com.betterjavacode.benefits.views, define a class UserClient which will extend a WebServiceGatewaySupport class. WebServiceGatewaySupport class provides web service methods.


package com.betterjavacode.benefits.views; 

import org.springframework.ws.client.core.support.WebServiceGatewaySupport; 
import org.springframework.ws.soap.client.core.SoapActionCallback; 
import com.betterjavacode.benefits.soap.GetUserRequest; 
import com.betterjavacode.benefits.soap.GetUserResponse; 

public class UserClient extends WebServiceGatewaySupport 
{

   public GetUserResponse getUserById(int userid) 
   { 
      GetUserRequest userrequest = new GetUserRequest(); userrequest.setId(userid); 
      GetUserResponse response = (GetUserResponse) getWebServiceTemplate().marshalSendAndReceive(userrequest, new SoapActionCallback("http://localhost:8080/benefits/endpoints/getUserResponse"));  
      return response;  
    }  
}

8.2 Configure the client for Spring Bean support

We will configure Jaxb2Marshaller to support JAXB to set context path. This will help us marshal and unmarshal our xml request and response through.


package com.betterjavacode.benefits.views; 

import org.springframework.context.annotation.Bean; 
import org.springframework.context.annotation.Configuration; 
import org.springframework.oxm.jaxb.Jaxb2Marshaller; 

@Configuration 
public class ClientAppConfig 
{ 

   @Bean 
   public Jaxb2Marshaller marshaller() 
   {  
       Jaxb2Marshaller marshaller = new Jaxb2Marshaller(); 
       marshaller.setContextPath("com.betterjavacode.benefits.soap"); 
       return marshaller;  
    } 
    
    @Bean 
    public UserClient userClient(Jaxb2Marshaller marshaller)  
    {  
        // WSDL URL - http://localhost:8080/benefits/endpoints/users.wsdl 
        UserClient uc = new UserClient(); 
        uc.setDefaultUri("http://localhost:8080/benefits/endpoints/users.wsdl"); 
        uc.setMarshaller(marshaller);  
        uc.setUnmarshaller(marshaller);
        return uc; 
     }  
}

8.3 Run the SOAP web service client

We will define a class with the main method to pass an argument of user id. Our client will call the web service with a passed argument to return the data if that user id exists in the database.

9. Conclusion

In this article, we showed how to create a SOAP web service and how to build a client to consume the same SOAP web service using Spring Boot. The code for this is available at github

10. References

  1. Spring Web services tutorial
  2. SOAP Web service producer and consumer
  3. Consuming a web service in java and SOAP UI

 

Consuming a RESTful Webservice – Part IV

Continuing the series of posts on Spring Boot, in this post, we will investigate how to consume a REST API service we built previously. This will be a short post on how to use Rest Template to call REST service. We will show how to read the data and how to post the data with some of the features Spring Boot offers to consume a REST service for the client-side.

The eventual goal is to use this feature to call our rest service during runtime to use the data from the database to display on views that a user will be able to see.

You can read previous posts on this series Part I, Part II, and Part III.

Purpose

The purpose of this post is to read company data from Company REST API and also to create a company by posting company data using the same REST API.

Build a client with Rest Template

To consume a rest service programmatically, Spring provides a feature called RestTemplate. RestTemplate is the easiest way for a client to interact with the server-side code with just one line of code.

In our client code, we will need a RestTemplate object, REST service URL. Since this is a sample we are building, we will be adding the main method in this class to run this client side of the code. In real-life scenarios, during runtime, client code will call the rest template to get server-side data, and use that data to massage or display to the user on the user interface.

 

RestTemplate restTemplate = new RestTemplate();
String resourceAPI_URL = "http://localhost:8080/benefits/v1/companies/{id}";
Company company = restTemplate.getForObject(resourceAPI_URL, Company.class, 1);

This code is showing that we are calling REST service to read company data for a company with id that a client will pass.

Similarly, we will have another request to post the data on the server side to create a company. The code for that will look like below:

String resourceAPI_POSTURL = "http://localhost:8080/benefits/v1/companies/";

Company comp = new Company();

comp.setName("XYZ Company");
comp.setStatusid(1);
comp.setType("Corporation");
comp.setEin("9343423232");

Company newcomp = restTemplate.postForObject(resourceAPI_POSTURL, comp, Company.class);

In this post, we showed how to use RestTemplate a feature that Spring Boot provides to consume a REST service. The code for this is available here

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