List of practiced topics

Configuration

1. Create a Maven web app project
2. Configure POM file [pom.xml]
   • Change JDK version (Servlet 3.0 require JDK 6+)
   • spring-webmvc dependency: support Spring MVC and REST
   • com.fasterxml.jackson.core/jackson-databind dependency: convert JSON
   • javax.servlet/javax.servlet-api dependency: support Servlet
   • javax.servlet.jsp/javax.servlet.jsp-api dependency: support JSP (get rid of Eclipse error)
   • maven-war-plugin plugin: support Maven war plugin
3. Update Maven project (Alt+F5)
4. Configure by Java for Spring MVC [Reference]
   • Spring Config [AppConfig]
   • Spring MVC Initializer [SpringMvcInitializer]
5. Create a Rest Controller (Service) [DemoRestController]
   • @RestController
   • @RequestMapping
   • Add endpoint (method)
6. Test Spring REST by running project on server and access the created endpoint (url)

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Main Process

1. Create POJO class [Student]
2. Create Rest Controller with @RestController and @RequestMapping [StudentRestController]
3. Add endpoints to the Controller
   • @PathVariable: bind URL variable to method parameter

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Global Exception Handling

1. Create custom Error Response class (POJO) [StudentErrorResponse]
2. Create custom Exception extends RuntimeException [StudentNotFoundException]
3. Update REST service to throw exception [StudentRestController]
4. Create a Exception Handler class with @ControllerAdvice (for Global Handling) [StudentRestExceptionHandler]
   • Add a custom exception handler and a generic exception handler with @ExceptionHandler (for Local Handling, put in the Controller)

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Notes/Tips

• If src/main/java and src/test/java are not availalbe, go to Build Path -> Order and Export -> Choose JRE and Maven Dependencies.
• Default welcome page: index.jsp inside src/main/webapp
• REST controller automatically converts between JSON and Java POJO using Jackson
• Get the Context Root: ${pageContext.request.contextPath}
• Change Servlet 2.3 (generated by archertype webapp) to Servlet 3.0, to use ${pageContext.request.contextPath}
  • Modify web.xml file in src/main/webapp/WEB-INF [web.xml]
  • Close project and delete it from the workspace (don't delete files on the disk)
  • Delete .project and .classpath files and .settings directory from the project folder
  • Re-import project: Import -> Existing Maven Project
  • Clean the server
• [!] Eclipse default browser does not display JSON -> Use external browsers or Postman
• Append "?" to end of URL to get reload fresh data
• Prefer Global Exception Handling for many controllers using @ControllerAdvice (real-time use of AOP)
• Naming convention for API/endpoints: use only entity, not the action. For example: /api/customers/ instead of /api/getCustomers/
• Path variable: {var} or :var
• Secure Spring REST API [URL]