JAX-RS API using Jersey [BAEL-558] (#956)

* WatchService vs. Apache Commons IO Mnitoring

* Indentation fixed

* Indentation fixed

* JAX-RS API using Jersey [BAEL-558]

* JAX-RS API using Jersey [BAEL-558]

* Modifications made to remove xml

* applicationContext.xml removed

* All try catch moved to ExceptionMapper

* fixes

* review comments incorporated

* module renamed

pom.xml

@@ -117,6 +117,7 @@
         <module>spring-hibernate3</module>
         <module>spring-hibernate4</module>
         <module>spring-integration</module>
+        <module>spring-jersey</module>		
         <module>spring-jms</module>
         <module>spring-jooq</module>
         <module>spring-jpa</module>

spring-jersey/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

spring-jersey/README.md

@@ -0,0 +1,3 @@
+=========
+
+## REST API with Jersey & Spring Example Project

spring-jersey/pom.xml

@@ -0,0 +1,210 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>jersey-api</artifactId>
+    <version>0.1-SNAPSHOT</version>
+    <packaging>war</packaging>
+
+    <properties>
+        <jersey.version>2.25</jersey.version>
+        <jcl.slf4j.version>1.7.22</jcl.slf4j.version>
+        <logback.version>1.1.8</logback.version>
+        <junit.version>4.12</junit.version>
+        <maven-war-plugin.version>3.0.0</maven-war-plugin.version>
+        <maven-surefire-plugin.version>2.19.1</maven-surefire-plugin.version>
+        <cargo-maven2-plugin.version>1.6.1</cargo-maven2-plugin.version>
+        <junit.version>4.12</junit.version>
+        <httpcore.version>4.4.5</httpcore.version>
+        <httpclient.version>4.5.2</httpclient.version>
+        <servlet-api-version>3.1.0</servlet-api-version>
+    </properties>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <artifactId>maven-war-plugin</artifactId>
+                <version>${maven-war-plugin.version}</version>
+                <configuration>
+                    <failOnMissingWebXml>false</failOnMissingWebXml>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>${maven-surefire-plugin.version}</version>
+                <configuration>
+                    <excludes>
+                        <exclude>**/*IntegrationTest.java</exclude>
+                        <exclude>**/*LiveTest.java</exclude>
+                    </excludes>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.codehaus.cargo</groupId>
+                <artifactId>cargo-maven2-plugin</artifactId>
+                <version>${cargo-maven2-plugin.version}</version>
+                <configuration>
+                    <wait>true</wait>
+                    <container>
+                        <containerId>jetty8x</containerId>
+                        <type>embedded</type>
+                    </container>
+                    <configuration>
+                        <properties>
+                            <cargo.servlet.port>8082</cargo.servlet.port>
+                        </properties>
+                    </configuration>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+
+        <!-- core library -->
+
+        <dependency>
+            <groupId>org.glassfish.jersey.core</groupId>
+            <artifactId>jersey-server</artifactId>
+            <version>${jersey.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.containers</groupId>
+            <artifactId>jersey-container-servlet</artifactId>
+            <version>${jersey.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.media</groupId>
+            <artifactId>jersey-media-json-jackson</artifactId>
+            <version>${jersey.version}</version>
+        </dependency>
+        <!-- servlet api -->
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+            <version>${servlet-api-version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <!-- optional library -->
+
+        <dependency>
+            <groupId>org.glassfish.jersey.ext</groupId>
+            <artifactId>jersey-spring3</artifactId>
+            <version>${jersey.version}</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>commons-logging</groupId>
+                    <artifactId>commons-logging</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>jcl-over-slf4j</artifactId>
+            <version>${jcl.slf4j.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback.version}</version>
+        </dependency>
+
+        <!-- http client -->
+
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+            <version>${httpclient.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpcore</artifactId>
+            <version>${httpcore.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- junit -->
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <profiles>
+        <profile>
+            <id>live</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>integration-test</phase>
+                                <goals>
+                                    <goal>test</goal>
+                                </goals>
+                                <configuration>
+                                    <excludes>
+                                        <exclude>**/*IntegrationTest.java</exclude>
+                                    </excludes>
+                                    <includes>
+                                        <include>**/*LiveTest.java</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                        <configuration>
+                            <systemPropertyVariables>
+                                <test.mime>json</test.mime>
+                            </systemPropertyVariables>
+                        </configuration>
+                    </plugin>
+                    <plugin>
+                        <groupId>org.codehaus.cargo</groupId>
+                        <artifactId>cargo-maven2-plugin</artifactId>
+                        <version>${cargo-maven2-plugin.version}</version>
+                        <configuration>
+                            <wait>false</wait>
+                        </configuration>
+                        <executions>
+                            <execution>
+                                <id>start-server</id>
+                                <phase>pre-integration-test</phase>
+                                <goals>
+                                    <goal>start</goal>
+                                </goals>
+                            </execution>
+                            <execution>
+                                <id>stop-server</id>
+                                <phase>post-integration-test</phase>
+                                <goals>
+                                    <goal>stop</goal>
+                                </goals>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+</project>

spring-jersey/src/main/java/com/baeldung/server/config/ApplicationInitializer.java

@@ -0,0 +1,22 @@
+package com.baeldung.server.config;
+
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
+import org.springframework.web.WebApplicationInitializer;
+import org.springframework.web.context.ContextLoaderListener;
+import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
+
+@Order(Ordered.HIGHEST_PRECEDENCE)
+public class ApplicationInitializer implements WebApplicationInitializer {
+
+    @Override
+    public void onStartup(ServletContext servletContext) throws ServletException {
+        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
+        servletContext.addListener(new ContextLoaderListener(context));
+        servletContext.setInitParameter("contextConfigLocation", "com.baeldung.server");
+    }
+
+}

spring-jersey/src/main/java/com/baeldung/server/config/RestConfig.java

@@ -0,0 +1,19 @@
+package com.baeldung.server.config;
+
+import javax.ws.rs.ApplicationPath;
+import javax.ws.rs.core.Application;
+
+import com.baeldung.server.exception.AlreadyExistsExceptionHandler;
+import com.baeldung.server.exception.NotFoundExceptionHandler;
+import com.baeldung.server.rest.EmployeeResource;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+@ApplicationPath("/resources")
+public class RestConfig extends Application {
+    public Set<Class<?>> getClasses() {
+        return new HashSet<Class<?>>(Arrays.asList(EmployeeResource.class, NotFoundExceptionHandler.class, AlreadyExistsExceptionHandler.class));
+    }
+}

spring-jersey/src/main/java/com/baeldung/server/exception/AlreadyExistsExceptionHandler.java

@@ -0,0 +1,12 @@
+package com.baeldung.server.exception;
+
+import javax.ws.rs.core.Response;
+import javax.ws.rs.ext.ExceptionMapper;
+import javax.ws.rs.ext.Provider;
+
+@Provider
+public class AlreadyExistsExceptionHandler implements ExceptionMapper<EmployeeAlreadyExists> {
+    public Response toResponse(EmployeeAlreadyExists ex) {
+        return Response.status(Response.Status.CONFLICT.getStatusCode()).build();
+    }
+}

spring-jersey/src/main/java/com/baeldung/server/exception/EmployeeAlreadyExists.java

@@ -0,0 +1,5 @@
+package com.baeldung.server.exception;
+
+public class EmployeeAlreadyExists extends RuntimeException {
+
+}

spring-jersey/src/main/java/com/baeldung/server/exception/EmployeeNotFound.java

@@ -0,0 +1,5 @@
+package com.baeldung.server.exception;
+
+public class EmployeeNotFound extends RuntimeException {
+
+}

spring-jersey/src/main/java/com/baeldung/server/exception/NotFoundExceptionHandler.java

@@ -0,0 +1,12 @@
+package com.baeldung.server.exception;
+
+import javax.ws.rs.core.Response;
+import javax.ws.rs.ext.ExceptionMapper;
+import javax.ws.rs.ext.Provider;
+
+@Provider
+public class NotFoundExceptionHandler implements ExceptionMapper<EmployeeNotFound> {
+    public Response toResponse(EmployeeNotFound ex) {
+        return Response.status(Response.Status.NOT_FOUND).build();
+    }
+}

spring-jersey/src/main/java/com/baeldung/server/model/Employee.java

@@ -0,0 +1,34 @@
+package com.baeldung.server.model;
+
+import javax.xml.bind.annotation.XmlRootElement;
+
+@XmlRootElement
+public class Employee {
+    private int id;
+    private String firstName;
+
+    public Employee() {
+
+    }
+
+    public Employee(int id, String firstName) {
+        this.id = id;
+        this.firstName = firstName;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+}

spring-jersey/src/main/java/com/baeldung/server/repository/EmployeeRepository.java

@@ -0,0 +1,18 @@
+package com.baeldung.server.repository;
+
+import java.util.List;
+
+import com.baeldung.server.model.Employee;
+
+public interface EmployeeRepository {
+
+    public List<Employee> getAllEmployees();
+
+    public Employee getEmployee(int id);
+
+    public void updateEmployee(Employee employee, int id);
+
+    public void deleteEmployee(int id);
+
+    public void addEmployee(Employee employee);
+}

spring-jersey/src/main/java/com/baeldung/server/repository/EmployeeRepositoryImpl.java

@@ -0,0 +1,65 @@
+package com.baeldung.server.repository;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.stereotype.Component;
+
+import com.baeldung.server.exception.EmployeeAlreadyExists;
+import com.baeldung.server.exception.EmployeeNotFound;
+import com.baeldung.server.model.Employee;
+
+@Component
+public class EmployeeRepositoryImpl implements EmployeeRepository {
+    private List<Employee> employeeList;
+
+    public EmployeeRepositoryImpl() {
+        employeeList = new ArrayList<Employee>();
+        employeeList.add(new Employee(1, "Jane"));
+        employeeList.add(new Employee(2, "Jack"));
+        employeeList.add(new Employee(3, "George"));
+    }
+
+    public List<Employee> getAllEmployees() {
+        return employeeList;
+    }
+
+    public Employee getEmployee(int id) {
+        for (Employee emp : employeeList) {
+            if (emp.getId() == id) {
+                return emp;
+            }
+        }
+        throw new EmployeeNotFound();
+    }
+
+    public void updateEmployee(Employee employee, int id) {
+        for (Employee emp : employeeList) {
+            if (emp.getId() == id) {
+                emp.setId(employee.getId());
+                emp.setFirstName(employee.getFirstName());
+                return;
+            }
+        }
+        throw new EmployeeNotFound();
+    }
+
+    public void deleteEmployee(int id) {
+        for (Employee emp : employeeList) {
+            if (emp.getId() == id) {
+                employeeList.remove(emp);
+                return;
+            }
+        }
+        throw new EmployeeNotFound();
+    }
+
+    public void addEmployee(Employee employee) {
+        for (Employee emp : employeeList) {
+            if (emp.getId() == employee.getId()) {
+                throw new EmployeeAlreadyExists();
+            }
+        }
+        employeeList.add(employee);
+    }
+}

spring-jersey/src/main/java/com/baeldung/server/rest/EmployeeResource.java

@@ -0,0 +1,64 @@
+package com.baeldung.server.rest;
+
+import java.util.List;
+
+import javax.ws.rs.Consumes;
+import javax.ws.rs.DELETE;
+import javax.ws.rs.GET;
+import javax.ws.rs.POST;
+import javax.ws.rs.PUT;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.UriInfo;
+
+import org.springframework.beans.factory.annotation.Autowired;
+
+import com.baeldung.server.model.Employee;
+import com.baeldung.server.repository.EmployeeRepository;
+
+@Path("/employees")
+public class EmployeeResource {
+
+    @Autowired
+    private EmployeeRepository employeeRepository;
+
+    @GET
+    @Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
+    public List<Employee> getAllEmployees() {
+        return employeeRepository.getAllEmployees();
+    }
+
+    @GET
+    @Path("/{id}")
+    @Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
+    public Employee getEmployee(@PathParam("id") int id) {
+        return employeeRepository.getEmployee(id);
+    }
+
+    @PUT
+    @Path("/{id}")
+    @Consumes({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
+    public Response updateEmployee(Employee employee, @PathParam("id") int id) {
+        employeeRepository.updateEmployee(employee, id);
+        return Response.status(Response.Status.OK.getStatusCode()).build();
+    }
+
+    @DELETE
+    @Path("/{id}")
+    @Consumes({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
+    public Response deleteEmployee(@PathParam("id") int id) {
+        employeeRepository.deleteEmployee(id);
+        return Response.status(Response.Status.OK.getStatusCode()).build();
+    }
+
+    @POST
+    @Consumes({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
+    public Response addEmployee(Employee employee, @Context UriInfo uriInfo) {
+        employeeRepository.addEmployee(new Employee(employee.getId(), employee.getFirstName()));
+        return Response.status(Response.Status.CREATED.getStatusCode()).header("Location", String.format("%s/%s", uriInfo.getAbsolutePath().toString(), employee.getId())).build();
+    }
+}

spring-jersey/src/main/resources/logback.xml

@@ -0,0 +1,15 @@
+<configuration>
+
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>web - %date [%thread] %-5level %logger{36} -
+                %message%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+
+</configuration>

spring-jersey/src/test/java/com/baeldung/server/JerseyApiLiveTest.java

@@ -0,0 +1,91 @@
+package com.baeldung.server;
+
+import java.io.IOException;
+
+import org.apache.http.HttpResponse;
+import org.apache.http.HttpStatus;
+import org.apache.http.client.ClientProtocolException;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.client.methods.HttpUriRequest;
+import org.apache.http.entity.StringEntity;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.junit.Test;
+
+import com.baeldung.server.model.Employee;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class JerseyApiLiveTest {
+
+    private static final String SERVICE_URL = "http://localhost:8082/jersey-api/resources/employees";
+
+    @Test
+    public void givenGetAllEmployees_whenCorrectRequest_thenResponseCodeSuccess() throws ClientProtocolException, IOException {
+        final HttpUriRequest request = new HttpGet(SERVICE_URL);
+
+        final HttpResponse httpResponse = HttpClientBuilder.create().build().execute(request);
+
+        assert(httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK);
+    }
+
+    @Test
+    public void givenGetEmployee_whenEmployeeExists_thenResponseCodeSuccess() throws ClientProtocolException, IOException {
+        final HttpUriRequest request = new HttpGet(SERVICE_URL + "/1");
+
+        final HttpResponse httpResponse = HttpClientBuilder.create().build().execute(request);
+
+        assert(httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK);
+    }
+
+    @Test
+    public void givenGetEmployee_whenEmployeeDoesNotExist_thenResponseCodeNotFound() throws ClientProtocolException, IOException {
+        final HttpUriRequest request = new HttpGet(SERVICE_URL + "/1000");
+
+        final HttpResponse httpResponse = HttpClientBuilder.create().build().execute(request);
+
+        assert(httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_NOT_FOUND);
+    }
+
+    @Test
+    public void givenGetEmployee_whenJsonRequested_thenCorrectDataRetrieved() throws ClientProtocolException, IOException {
+        final HttpUriRequest request = new HttpGet(SERVICE_URL + "/1");
+
+        request.setHeader("Accept", "application/json");
+        final HttpResponse httpResponse = HttpClientBuilder.create().build().execute(request);
+        ObjectMapper mapper = new ObjectMapper();
+        Employee emp = mapper.readValue(httpResponse.getEntity().getContent(), Employee.class);
+
+        assert(emp.getFirstName().equals("Jane"));
+    }
+
+    @Test
+    public void givenAddEmployee_whenJsonRequestSent_thenResponseCodeCreated() throws ClientProtocolException, IOException {
+        final HttpPost request = new HttpPost(SERVICE_URL);
+
+        Employee emp = new Employee(5, "Johny");
+        ObjectMapper mapper = new ObjectMapper();
+        String empJson = mapper.writeValueAsString(emp);
+        StringEntity input = new StringEntity(empJson);
+        input.setContentType("application/json");
+        request.setEntity(input);
+        final HttpResponse httpResponse = HttpClientBuilder.create().build().execute(request);
+
+        assert(httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_CREATED);
+    }
+
+    @Test
+    public void givenAddEmployee_whenRequestForExistingObjectSent_thenResponseCodeConflict() throws ClientProtocolException, IOException {
+        final HttpPost request = new HttpPost(SERVICE_URL);
+
+        Employee emp = new Employee(1, "Johny");
+        ObjectMapper mapper = new ObjectMapper();
+        String empJson = mapper.writeValueAsString(emp);
+        StringEntity input = new StringEntity(empJson);
+        input.setContentType("application/json");
+        request.setEntity(input);
+        final HttpResponse httpResponse = HttpClientBuilder.create().build().execute(request);
+
+        assert(httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_CONFLICT);
+    }
+
+}