title	link
Webapplicaties IV	https://robinmalfait.com/2de-jaar/semester-II/Webapplicaties-IV.md

Taglib	link
jstl core	`<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>`
jstl fmt	`<%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>`
form	`<%@taglib prefix="form" uri="http://www.springframework.org/tags/form"%>`
spring	`<%@taglib prefix="spring" uri="http://www.springframework.org/tags"%>`

Deel 1

JSP

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>

<!-- Imports -->
<%@page import="java.util.Date" %>
<html>
    <head>
        <meta charset="utf-8">
        <meta http-equiv="refresh" content="1"/> <!-- Refesh each second -->
        <title></title>
    </head>
    <body>
        <!-- JSP Expression to insert date/time -->
        <% out.print(new java.util.Date()) %>

        <!-- Without out.print -->
        <%= new java.util.Date() %>

        <!-- Because of the import -->
        <%= new Date() %>
    </body>
</html>

Expression Language (EL)

Using scripting

<!DOCTYPE html>
<html>
    <body>
        <% domain.Circle circle = (domain.Circle) request.getAttribute('circle') %>
        Radius of the circle is: <%= circle.getRadius() %>
    </body>
</html>

Using EL

<!DOCTYPE html>
<html>
    <body>
        Radius of the circle is: ${circle.radius}
    </body>
</html>

Arrays

<!DOCTYPE html>
<html>
    <body>
        Colors are: ${colorList}
        First color is: ${colorList[0]}
    </body>
</html>

Includes

<!DOCTYPE html>
<html>
    <body>
        <jsp:iclude page="header.jsp"/>
        JSP Page...
        <jsp:iclude page="footer.jsp"/>
    </body>
</html>

Includes with params

header.jsp

<h2>${param.title}</h2>

yourPage.jsp

<!DOCTYPE html>
<html>
    <body>
        <jsp:include pae="../WEB-INF/header.jsp">
            <jsp:param name="title" value="this is the header" />
        </jsp:include>
        JSP Page...
    </body>
</html>

Redirects/Forwards

Using scripting

<!DOCTYPE html>
<html>
    <body>
        Welcome to our page!
        <% if(request.getParameter("userName") == null) { %>
            <jsp:forward page="HandleIt.jsp"/>
        <% } %>

        Hello ${param.userName}
    </body>
</html>

Using more JSTL

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
    <body>
        Welcome to our page!
        <c:if test="${empty param.userName}">
            <jsp:forward page="HandleIt.jsp"/>
        </c:if>

        Hello ${param.userName}
    </body>
</html>

JSTL

JSP Standard Tag Library

Core Library <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
- <c:out>
- <c:set>
- <c:remove>
- <c:catch>
- <c:if>
- <c:choose>
- <c:when>
- <c:otherwise>
- <c:import>
- <c:url>
- <c:redirect>
- <c:param>
- <c:forEach>
- <c:forEachToken>
Formatting Library <%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
- Internationalization
  - <fmt:message>
  - <fmt:setLocale>
  - <fmt:bundle>
  - <fmt:setBundle>
  - <fmt:param>
  - <fmt:requestEncoding>
- Formatting
  - <fmt:timeZone>
  - <fmt:setTimeZone>
  - <fmt:formatNumber>
  - <fmt:parseNumber>
  - <fmt:parseDate>

c:forEach

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
    <body>
        <c:forEach var="color" items="${colorArray}">
            ${color}
        </c:forEach>

        <c:forEach var="color" items="${colorArray}" varStatus="index">
            ${index} ${color}
        </c:forEach>
    </body>
</html>

c:if

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
    <body>
        <p>Comments:</p>
        <p>${commentList}</p>

        <c:if test="${userType == 'student'}">
            <jsp:include page="inputComments.jspf"/>
        </c:if>
    </body>
</html>

c:choose, c:when and c:otherwise

<c:choose> -> switch
<c:when> -> case
<c:otherwise> -> default

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
    <body>
        <c:choose>
            <c:when test="${userType == 'student'}">
                <jsp:include page="inputComments.jspf"/>
            </c:when>
            <c:when test="${userType == 'professor'}">
                Professor
            </c:when>
            <c:otherwise>Person</c:otherwise>
        </c:choose>
    </body>
</html>

c:import

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
    <body>
        <c:import url="http://rbn.nu/"/>
    </body>
</html>

Deel 2 - Spring Basis

POJO: Plain Old Java Object

Inversion of Control (IoC) - Dependency Injection

Without IoC

Wanneer je een nieuwe operatie wil toevoegen, moet je deze code aanpassen en dus terug helemaal compilen.

public class Calculate {
    public static void main(String[] args) {
        long op1 = Long.parseLong(args[0]);
        long op2 = Long.parseLong(args[1]);

        showResult("The result of " + op1 + getOpsName() + op2 + " is " + operate(op1, op2) + "!");
    }

    private void showResult(String result) {
        Syste.out.println(result);
    }

    private long operate(long op1, long op2) {
        return op1 + op2;
    }

    private String getOpsName() {
        return " plus ";
    }
}

IoC way

Als je nu een nieuwe operatie wilt toevoegen, moet je maar een klasse bij maken, en niet de calculator klasse opnieuw compilen.

// Operations
public interface Operation {
    public long operate(long op1, long op2);
    public String getName();
}

public class OperationAdd implements Operation {
    public long operate(long op1, long op2) {
        return op1 + op2;
    }

    public String getName() {
        return " plus ";
    }
}

// Output
public interface ResultWriter {
    public void showResult(String result);
}

public class ScreenWriter implements ResultWriter {
    public void showResult(String result) {
        System.out.println(result);
    }
}

// Domain
public class CalculateSpring {
    private Operation ops;
    private ResultWriter writer;

    public void setOps(Operation ops) {
        this.ops = ops;
    }

    public void setWriter(ResultWriter writer) {
        this.writer = writer;
    }

    public void execute(String[] args) {
        long op1 = Long.parseLong(args[0]);
        long op2 = Long.parseLong(args[1]);

        writer.showResult("The result of " + op1 + ops.getOpsName() + op2 + " is " + ops.operate(op1, op2) + "!")
    }
}

// Spring StartUp
public class StartUp {
    public static void main (String... args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        CalculateSpring opsbean = context.getBean("opsbean", CalculateSpring.class);

        opsbean.execute(args);
    }
}

Wiring beans

Annotations

@Service("...") // This is a dependency

@Autowired // Spring will inject the dependency here

@Resource(name = "...") // This is @Autowired with name parameter

@Qualifier
    @Autowired
    @Qualifier("screen")

    // =

    @Resource(name = "screen")

Deel 3 - Spring Web MVC

Structuur

A Model

package domain;

public interface HelloService {
    public String sayHello(String name);
}

public class HelloServiceImpl implements HelloService {
    @Override
    public String sayHello(String name) {
        return String.format("Hello %s!", name != null ? name : "")
    }
}

Controller

package controller;

public class Name {
    private String value;

    public String getValue() { return value; }
    public String setValue(String v) { value = v; }
}

@Controller
public class HelloController {

    @Autowired
    private HelloService helloService; // Dependency Injection

    @RequestMapping(value = {"/hello"}, method = RequestMapping.GET)
    public String showHomePage(Model model) {
        model.addAttribute("name", new Name());
        return "nameForm";
    }

    @RequestMapping(value = {"/hello"}, method = RequestMapping.POST)
    public String onSubmit(@ModelAttribute Name name, Model model) {
        model.addAttribute("helloMessage", helloService.sayHello(name.getValue()));
        return "helloView";
    }
}

Views

WEB-INF/jsp/nameForm.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>Enter your name</title>
    </head>
    <body>
        <h1>Enter your name</h1>
        <!--
        method corresponds with RequestMethod.POST in controller method
        action corresponds with value in controller method
        -->
        <form:form method="POST" action="hello.htm">
            Name:
            <form:input path="value" size="15" />
            <input type="submit" value="OK"/>
        </form:form>
    </body>
</html>

WEB-INF/jsp/helloView.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>Hello</title>
    </head>
    <body>
        <h2>${helloMessage}</h2>
    </body>
</html>

Config classes

WebConfig

package config;

import domain.Product;
import domain.ProductManager;
import domain.SimpleProductManager;
import java.util.ArrayList;
import java.util.Arrays;
import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import validator.PercentValidation;

@Configuration
@EnableWebMvc
@ComponentScan("controller")
public class WebConfig extends WebMvcConfigurerAdapter
{
    @Bean
    public HelloService helloService()
    {
        return new HelloServiceImpl();
    }

    @Bean
    public ViewResolver viewResolver()
    {
        InternalResourceViewResolver resolver
                = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/jsp/");
        resolver.setSuffix(".jsp");
        return resolver;
    }
}

SpringMvcInitializer

package config.core;

import config.WebConfig;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class SpringMvcInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{ WebConfig.class };
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return null;
    }

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
}

Request Mapping (Uitgebreid)

@Controller
@RequestMapping("/member/*")
public class MemberController {
    @RequestMapping("add") // Url: /member/add
    public String addMember(Model model) { /* ... */}

    @RequestMapping(value={"remove", "delete"}, method=RequestMethod.GET) // Url: /member/remove or /member/delete
    public String addMember(Model model) { /* ... */}
}

Formatting & Validatie

Via Annotation

@NumberFormat // has optional attributes: Style & Pattern

public class Account {
    @NumberFormat(pattern = "#,##0.00")
    private BigDecimal balance = new BigDecimal("20003000.2599") // 20.003.00,26

    @NumberFormat(style = Style.PERCENT)
    private double percent = 0.25; // 25%

    @DateTimeFormat(style = "MM")
    private Date activationDate = new Date();

    @DateTimeFormat(style = "dd/MM/yyy")
    private Date currentDate = new Date();
}

public class Registration {
    @Pattern(regexp = "^[a-zA-Z]+", message = "username must be alphanumeric with no spaces")
    private String userName;

    @Size(min = 4, max = 20)
    private String password;

    @NotEmpty
    private String confirmPassword;

    @NotEmpty
    @Email
    private String email;
}

public class ForStrings {
    @NotEmpty
    private String someString;

    @NotEmpty(message = "Password must not be blank")
    private String someString1;

    @Size(min = 1, max = 20)
    private String someString2;

    @Size(min = 1, max = 20, message = "Password must be between 1 to 20 characters")
    private String someString3;

    @Email
    private String someString4;

    @Pattern(regexp = "^[a-zA-Z]+")
    private String someString4;
}

public class ForNumbers {
    @NotNull
    private int someNumber;

    @Min(1)
    private double someNumber1;

    @Max(110)
    private double someNumber2;

    @DecimalMin("20.50")
    @DecimalMin(value = "20.50", message = "Must be greater than or equal to 20.50")
    private double someNumber3;

    @DecimalMax("5000.50")
    private double someNumber4;

    @DecimalMax("5000.50")
    private double someNumber5;

    @Range(min = 10, max = 90)
    private double someNumber6;
}

Controller

@Controller
@RequestMapping("/registration")
public class RegistrationController {
    @RequestMapping(method = RequestMethod.GET)
    public String showRegistration(Model model) {
        model.addAttribute("registration", new Registration());
        return "registrationForm";
    }

    @RequestMapping(method = RequestMethod.POST)
    public String processRegistration(@Valid Registration registration, BindingResult result) {
        if (result.hasErrors()) {
            return "registrationForm";
        }

        return "registrationSuccess";
    }
}

JSTL (Zonder annotations formatten)

<%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<!DOCTYPE html>
<html>
    <head>
        <spring:url value="/css/style.css" var="urlCss"/>
        <link rel="stylesheet" href="${urlCss}" type="text/css"/>
    </head>
    <body>
        <!-- Output -->
        ${account.balance}
        ${account.percent}
        <spring:bind path="account.activationDate">${status.value}</spring:bind>
        <spring:bind path="account.currentDate">${status.value}</spring:bind>

        <!-- Format directly in the view -->
        <fmt:formatNumber value="${account.balance2}" pattern="#,##0.00"/>
        <fmt:formatNumber value="${account.percent2}" type="percent"/>

        <!-- Form validation -->
        <form:form method="POST" action="account.htm" commandName="account">
            <form:input path="activationDate"/>
            <form:input path="currentDate"/>
        </form:form>

        <!-- All Errors -->
        <form:errors path="*" cssClass="error"/>

        <!-- Form Errors -->
        <form:form method="POST" action="registration.htm" modelAttribute="registration">
            <form:input path="userName" size="20"/>
            <form:errors path="userName" cssClass="error"/>
        </form:form>
    </body>
</html>

Eigen validators

package validator;

import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;

public class RegistrationValidation implements Validator {
    @Override
    public boolean supports(Class<?> c) {
        return Registration.class.isAssignableFrom(c);
    }

    @Override
    public void validation(Object target, Errors errors) {
        Registration registration = (Registration) target;

        String userName = registration.getUserName();

        if (username.length() < 4 || userName.length() > 15) {
            errors.rejectValue("userName", "lengOfUser.registration.userName", "username must be between 4 and 15 characters long.");
        }

        if (!(registration.getPassword()).equals(registration.getConfirmPassword())) {
            errors.rejectValue("password", "machingPassword.registration.password", "Password does not match the confirm password");
        }
    }
}

public class WebConfig extends WebMvcConfigurerAdapter {
    // ...
    @Bean
    public RegistrationValidation registrationValidation() {
        return new RegistrationValidation();
    }
    // ...
}

@Controller
@RequestMapping("/registration")
public class RegistrationController {
    @Autowired
    private RegistrationValidation registrationValidation;

    @RequestMapping(method = RequestMethod.POST)
    // @Valid or @ModelAttribute
    public String processRegistration(@Valid Registration registration, BindingResult result, Model model) {
        registrationvalidation.validate(registration, result);
        registration.setConfirmPassword(null);
        registration.setPassword(null);

        if (result.hasErrors()) {
            return "registrationForm";
        }
    }
}

Custom validator annotations

package controller;

import validator.ValidEmail;

public class Registration {
    @ValidEmail
    private String email;
}

package validator;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.validation.Constraint;
import javax.validation.Payload;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Documented
@Constraint(validatedBy = EmailConstraintValidator.class)
@Target({ METHOD, FIELD })
@Retention(RUNTIME)
public @interface ValidEmail {
    String message() default "You must include a valid email";
    Class<?>[] groups() default{};
    Class<? extends Payload>[] payload() default{};
}

package validator;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

public class EmailConstraintValidator implements ConstraintValidator<ValidEmail, String> {
    @Override
    public void initialize(ValidEmail cosntraintAnnotation) {}

    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        // Disable default error messages
        context.disableDefaultConstraintViolation();

        // Custom Errors
        context.buildConstraintViolationWithTemplate("{myEmail.message}").addConstraintViolation();
        return value.contains("@");
    }
}

Spring Exceptions

<%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
<!DOCTYPE html>
<html>
    <body>
        Your reservation for ${exception.courtName} is not available on <fmt:formatDate value="${exception.date}" pattern="dd-MM-yyy"/> at ${exception.hour}:00.
    </body>
</html>

public class WebConfig {
    // ...
    @Bean
    public SimpleMappingExceptionResolver simpleMappingExceptoinResolver() {
        SimpleMappingExceptionResolver r = new SimpleMappingExceptionResolver();

        Properties mappings = new Properties();
        mappings.put("exception.ReservationNotAvailableException", "error/reservationNotAvailable");

        r.setDefaultErrorView("error/error");
        r.setExceptionMappings(mappings);

        return r;
    }
    // ...
}

package exception;

public class ReservationNotAvailableException extends RuntimeException {
    private final String courtName;
    private final Date date;
    private final int hour;

    public ReservationNotAvailableException(String courtName, Date date, int hour) {
        this.courtName = courtName;
        this.date = date;
        this.hour = hour;
    }

    // getters
}

@Controller
@RequestMapping("/welcome")
public class WelcomeController {
    @ExceptionHandler(CustomGenericException.class)
    public ModelAndView handleCustomException(CustomGenericException ex) {
        ModelAndView model = new ModelAndView("error/gener_error");
        model.addObject("errCode", ex.getErrCode());
        model.addObject("errMsg", ex.getErrMsg());
        return model;
    }
}

<!-- ... -->
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!-- ... -->
<body>
    <c:if test="${not empty errCode}">
        <h1>${errCode}; System Errors</h1>
    </c:if>

    <c:if test="${empty errCode}">
        <h1>System Errors</h1>
    </c:if>

    <c:if test="${not empty errMsg}">
        <h3>${errMsg}</h3>
    </c:if>
</body>

Handler Interceptors

package web;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import org.springframework.web.servlet.ModelAndView;

public class MeasurementInterceptor extends HandlerInterceptorAdapter {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        long startTime = System.curentTimeMillis();
        request.setAttribute("startTime", startTime);
        return true;
    }

    @Override
    public boolean postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView mav) throws Exception {
        long startTime = (Long) request.getAttribute("startTime");
        request.removeAttribuet("startTime");
        long endTime = System.currentTimeMillis();
        mav.addObject("handlingTime", endTime - startTime);
    }
}

public class WebConfig {
    // ...
    @Bean
    public MeasurementInterceptor measurementInterceptor() {
        return new MeasurementInterceptor();
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {

        // Enkel voor de welcome.htm
        registry.addInterceptor(measurementInterceptor()).addPathPatterns("/welcome.htm");

        // Voor alles
        registry.addInterceptor(measurementInterceptor()).addPathPatterns("/**");
    }
    // ...
}

Error messages & i18n

public class WebConfig {
    // ...
    @Bean
    public MessageSource messageSource() {
        ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();

        // Package: resources
        // Default file: messages.properties
        // NL file: messages_nl.properties
        messageSource.setBaseName("resources/messages");

        // welcome.message=Welcome to ...

        return messageSource;
    }
    // ...
}

<%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
<%@taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<spring:message code="welcome.message" var="tweedeOptie"/>
<!DOCTYPE html>
<html>
    <body>
        <h2><spring:message code="welcome.message"/></h2>
        <!-- of -->
        <h2>${labelWelcome}</h2>

        <hr/>
        Locale: ${pageContext.response.locale}

        <!-- FORMAT DATE -->
        <spring:message code="date.format.pattern" var="dateFormatPattern"/>
        Today is <fmt:formatDate value="${today}" pattern="${dateFormatPattern}"/>

        <!-- Bean Validation -->
        <form:input path="firstName"/>
        <form:errors path="firstName" cssClass="error"/>
    </body>
</html>

Default validation annotation messages overschrijden

public class WebConfig {
    // ...
    @Bean
    public MessageSource messageSource() {
        ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();

        // Package: default
        // Default file: ValidationMessages.properties
        messageSource.setBaseName("ValidationMessages");

        return messageSource;
    }
    // ...
}

@NotEmpty(message = "{validation.fistname.NotEmpty.message}")
@Size(min = 3, max = 60, message = "{validation.Size.message}")
private String firstName;

Validator class

public class DropDownBoxValidator implements Validator {
    public void validate(Object target, Errors errors) {
        Customer cust = (Customer) target;
        ValidationUtils.rejectIfEmptyOrWhitespace(errors, "javaSkills", "required.javaSkills", "required a java skill");

        if ("NONE".equalsIgnoreCase(cust.getCountry())) {
            errors.rejectValue("country", "required.country", "required country");
        }
    }
}

≤ NumberFormatException

public class PriceIncrease {
    private Integer percentage; // or int
}

@Controller
//...
model.addAttribute("PriceIncrease", new PriceIncrease());

<form:form method="post" action="increase.htm" modelAttribute="priceIncrease">
    <form:input path="percentage"/>
</form:form>

messages.properties: typeMismatch.<OBJECT_NAME>.<PROPERTY>=<MESSAGE>

typeMismatch.priceIncrease.precentage=my message!!!

i18n

converter.properties: contact_save_fail=failed saving contact

public class Message {
    private String type;
    private String message;

    public Message() {}
        public Message(String type, String message) {
            this.type = type;
            this.message = message;
        }
        // Getters & Setters
}

@Controller
@RequestMapping("/contacts")
public class ContactController {
    @Autowired
    private MessageSource messageSource;

    @RequestMapping(method = RequestMethod.POST)
    public String processRegistration(@Valid Registration registration, BindingResult result, Model model, Locale locale) {
        if (result.hasErrors()) {
            model.addAttribute("message", new Message("error", messageSource.getMessage("contact_save_fail", new Object[]{}, locale)));
            return "registrationForm";
        }
    }
}

<c:if test="${not empty message}">
    <div id="message" class="${message.type}">
        ${message.message}
    </div>
</c:if>

@Value

@Controller
public class AboutController {

    // Spring Expression Language (SpEL)
    @Value("#{ messageSource.getMessage('admin.email', null, 'en')}")
    private String email;

    @RequestMapping("/about")
    public String courtReservation(Model model) {
        model.addAttribute("email", email);
        return "about";
    }
}

LocaleResolver

public class WebConfig {
    // ...
    @Bean
    public LocaleResolver localeResolver() {
        CookieLocaleResolver localResolver = new CookieLocaleResolver();

        // ValidationMessages_nl.properties
        // messages_nl.properties
        localResolver.setDefaultLocale(new Locale("nl"));

        return localResolver;
    }
    // ...
}

Multiple Row

@Controller
@RequestMapping("/students")
public class StudentController {
    @Autowired
    private StudentService studentService;

    @RequestMapping(value = "/list", method = RequestMethod.GET)
    public String listStudents(Model model) {
        model.addAttribute("studentList", studentService.findAll());
        return "grade/listStudents";
    }

    @RequestMapping(value = "/list", method = RequestMethod.GET)
    public String listStudents(Model model) {
        return "grade/listStudents";
    }
}

<!DOCTYPE html>
<html>
    <spring:url value ="/students/" var="showGradeUrl"/>
    <body>
        <c:forEach items="${studentList}" var="student">
            <tr>
                <td>
                    <a href="${showGradeUrl}${student.id}.htm">${student.lastname}</a>
                </td>
                <td>${student.firstName}</td>
            </tr>
        </c:forEach>
    </body>
</html>

@Controller
@RequestMapping("/students")
public class StudentController {
    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    public String show(@PathVariable("id") Integer id, Model model) {
        Student student = studentService.findById(id);
        model.addAttribute("student", student);
        return "grade/detailStudent";
    }
}

Security

//...
@Import({ SecurityConfig.class })
//...
public class WebConfig extends WebMvcConfigurerAdapter {

}

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigureAdapter {
    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exceptoin {
        auth.inMemoryAuthentication()
            .withUser("user").password("user").roles("USER").and()
            .withuser("admin").password("admin").roles("USER", "ADMIN");
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        // Option 1: Basic Security (popup)
        http.httpBasic();

        // Option 2: Basic form security
        http.formLogin().defaultSuccessUrl("/hello").loginPage("/login");

        http.authorizeRequests()
            .antMatchers("/*").hasRole("USER");

        // CSRF
        http.authorizeRequests()
            .antMatchers("/welcome*").hasRole("USER")
            .and().csrf()
    }
}

@Controller
public class HelloController {
    @RequestMapping(value = "/hello", method = RequestMethod.GET)
    public String printWelcome(Model model, Principal principal) {
        model.addAttribute("username", principal.getName());
        return "hello";
    }
}

Deel 5 Webservices

SOAP

Service Oriented Architecture (SOA) Protocol

WSDL

Web Service Definition Language

http://127.0.0.1:9876/ts?wsdl
Beschrijving van Web services in XML formaat:
- Abstracte beschrijving van operaties en parameters (berichten)
- Binden met een concreet netwerk protocol (bvb SOAP)
- Specificaties van endpoints voor toegang tot de service
Structuur WSDL document

@EnableWs
public class WebServiceConfig {
    // ...
    @Bean
    public JaxWsPortProxyFactoryBean hugeIntegerBean() throws MalformedURLException {
        JaxWsPortProxyFactoryBean proxy = new JaxWsPortProxyFactoryBean();

        proxy.setWsdlDocumentUrl(new URL("http://localhost:8080/webservices__HugeInteger/HugeInteger?WSDL"));
        proxy.setServiceName("HugeInteger");
        proxy.setPortName("HugeIntegerPort");
        proxy.setNamespaceUri("http://service/");
        proxy.setServiceInterface(IHugeInterface.class);

        return proxy;
    }
    // ...
}

package service;
@WebService
public interface IHugeInteger {
    public String add(@WebParam(name = "first") String first, @WebParam(name = "Second") String Second);
    public String substract(@WebParam(name = "first") String first, @WebParam(name = "Second") String Second);
}

public class HugeIntegerService extends SpringBeanAutowiringSupport {
    @Autowired
    private IHugeInteger hugeIntegerBean;

    public String calculateHugeIntegers(String first, String second, String operation) {
        switch(operation) {
            case "+":
                return hugeIntegerBean.ad(first, second);
            case "-":
                return HugeIntegerBean.substract(first, second);
        }
        return "";
    }
}

REST

REpresentional State Transfer

Meestal JSON (JavaScript Object Notation)

CRUD

Create: POST
Read: GET
Update: PUT
Delete: DELETE

POJO

Plain Old Java Object

Code

package domain;

import java.io.Serializable;
import java.util.Date;

import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.ser.std.DateSerializer;

public class Employee implements Serializable {
    private static final long serialVersionUID = 1L;

    private int id;
    private String name;
    private Date createdDate;

    // getters

    @JsonSerialize(using = DateSerializer.class)
    public Date getCreatedDate() {

    }
}

package controller;

public class EmpRestURIConstants {
    public static final String DUMMY_EMP = "/rest/emp/dummy";
    public static final String GET_EMP = "/rest/emp/{id}";
    public static final String GET_ALL = "/rest/emp";
    public static final String CREATE_EMP = "/rest/emp/create";
    public static final String DELETE_EMP = "/rest/emp/delete/{id}";
}

@RestController
public class EmployeeController {

    @RequestMapping(value = EmpRestURIConstants.DUMMY_EMP, method = RequestMethod.GET)
    public Employee getDummyEmployee() {
        Employee emp = new Employee();
        // ...
        return emp;
    }

}

public class WebConfig extends WebMvcConfigurerAdapter {
    @Bean
    public ViewResolver viewResolver() {
        return new ContentNegotiatingViewResolver();
    }

    @Override
    public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
        configurer.defaultContentType(MediaType.APPLICATION_JSON);
    }
}

Files

Webapplicaties-IV.md

Latest commit

History

Webapplicaties-IV.md

File metadata and controls

Deel 1

JSP

Expression Language (EL)

Using scripting

Using EL

Arrays

Includes

Includes with params

header.jsp

yourPage.jsp

Redirects/Forwards

Using scripting

Using more JSTL

JSTL

c:forEach

c:if

c:choose, c:when and c:otherwise

c:import

Deel 2 - Spring Basis

Inversion of Control (IoC) - Dependency Injection

Without IoC

IoC way

Wiring beans

Annotations

Deel 3 - Spring Web MVC

Structuur

A Model

Controller

Views

WEB-INF/jsp/nameForm.jsp

WEB-INF/jsp/helloView.jsp

Config classes

WebConfig

SpringMvcInitializer

Request Mapping (Uitgebreid)

Formatting & Validatie

Via Annotation

Controller

JSTL (Zonder annotations formatten)

Eigen validators

Custom validator annotations

Spring Exceptions

Handler Interceptors

Error messages & i18n

Default validation annotation messages overschrijden

Validator class

i18n

@Value

LocaleResolver

Multiple Row

Security

Deel 5 Webservices

SOAP

WSDL

REST

CRUD

POJO

Code