Rest API | Web Service Tutorial

I am using tomcat10 and jersey version 3.1.3 but not able to avoid this error - SEVERE: MessageBodyWriter not found for media type=application/xml, type=class com.jersey.demorest.Alien, genericType=class com.jersey.demorest.Alien.

Hi scuse me for my english. I tried to follow the tutorial but this error appears as soon as I invoke the rest "java.lang.NoClassDefFoundError: jakarta/servlet/Filter".
Tomcat 8 and java 1.8
The configuration is in the pom:

<properties>
<jersey.version>3.1.3</jersey.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<war.mvn.plugin.version>3.4.0</war.mvn.plugin.version>
</properties>


<dependencies>
<dependencies>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet-core</artifactId>
<!-- use the following artifactId if you don't need servlet 2.x compatibility -->
<!-- artifactId>jersey-container-servlet</artifactId -->
</dependency>

<dependencies>
<groupId>org.glassfish.jersey.inject</groupId>
<artifactId>jersey-hk2</artifactId>
</dependency>


<!-- uncomment this to get JSON support
<dependencies>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-json-binding</artifactId>
</dependency>
-->
</dependencies>

web.xml:
<servlet>
<servlet-name>Jersey Web Application</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>jersey.config.server.provider.packages</param-name>
<param-value>com.telusko.demorest</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Jersey Web Application</servlet-name>
<url-pattern>/webapi/*</url-pattern>
</servlet-mapping>

Help me Thaks

Awesome explanation, seeing this in 2023

In this video details of RestAPI is just 10% and remaining 90% consist of jersey project creation, Spring project creation, jdbc etc.

@RestController
@RequestMapping(value = "/employee")
public class EmployeeController {

@Autowired
private EmployeeRep employeeRep;

@GetMapping("/one")
public Map<String, Long> maleAndFemaleEmployees() {
List<Employee> noOfMaleAndFemaleEmployees = employeeRep.findAll();

Map<String, Long> collect = noOfMaleAndFemaleEmployees.stream()
.collect(Collectors.groupingBy(Employee::getGender, Collectors.counting()));
return collect;

}

@GetMapping("/two")
public Stream<String> findAllEmpDeptDistinct() {
List<Employee> findAll = employeeRep.findAll();

Stream<String> distinct = findAll.stream().map(app -> app.getDept()).distinct();

return distinct;

}

@GetMapping("/three")
public Map<String, Double> avgAgeOfMaleAndFemale() {
List<Employee> avgAgeOfMaleAndFemaleEmployees = employeeRep.findAll();

Map<String, Double> collect = avgAgeOfMaleAndFemaleEmployees.stream()
.collect(Collectors.groupingBy(Employee::getGender, Collectors.averagingDouble(Employee::getAge)));
return collect;

}

@GetMapping("/four")
public Optional<Employee> highPaidEmployee() {
List<Employee> highestPaidDetailFull = employeeRep.findAll();

Optional<Employee> max = highestPaidDetailFull.stream()
.collect(Collectors.maxBy(Comparator.comparingDouble(Employee::getSalary)));
return max;
}

@GetMapping("/five")
public ResponseEntity<String> highestPaidEmployee() {
List<Employee> highestPaid = employeeRep.findAll();

Optional<Employee> max = highestPaid.stream().max(Comparator.comparing(Employee::getSalary));

if (max.isPresent()) {
Employee employee = max.get();
String name = employee.getName();
String department = employee.getDept();

String response = "Highest Paid Employee: " + name + " (Department: " + department + ")";
return ResponseEntity.ok(response);
} else {
return ResponseEntity.notFound().build();
}
}

@GetMapping("/six")
public Stream<String> joinedafter2015() {
List<Employee> findAll = employeeRep.findAll();

Stream<String> map = findAll.stream().filter(te -> te.getYearOfJoining() > 2015).map(Employee::getName);
return map;
}

@GetMapping("/seven")
public Map<String, Long> employeeCountByDepartment() {
List<Employee> countByDepartment = employeeRep.findAll();

Map<String, Long> collect = countByDepartment.stream()
.collect(Collectors.groupingBy(Employee::getDept, Collectors.counting()));

return collect;

}

@GetMapping("/eight")
public Map<String, Double> avgSalaryOfDepartments() {
List<Employee> avgSalaryOfDepts = employeeRep.findAll();

Map<String, Double> collect = avgSalaryOfDepts.stream()
.collect(Collectors.groupingBy(Employee::getDept, Collectors.averagingDouble(Employee::getSalary)));

return collect;

}

@GetMapping("/nine")
public Optional<Employee> youngestMaleEmployeeInProductDevelopment() {
List<Employee> youngestMaleEmployeeInProductDeve = employeeRep.findAll();

Optional<Employee> max = youngestMaleEmployeeInProductDeve.stream()
.filter(te -> te.getGender().equals("Male") && te.getDept().equals("Product Development"))
.min(Comparator.comparing(Employee::getAge));

return max;

}

@GetMapping("/ten")
public Optional<Employee> seniorMostEmployee() {
List<Employee> seniorEmployee = employeeRep.findAll();

Optional<Employee> collect = seniorEmployee.stream()
.collect(Collectors.minBy(Comparator.comparing(Employee::getYearOfJoining)));
return collect;

}

@GetMapping("/eleven")
public Map<String, Long> countMaleFemaleEmployeesInSalesMarketing() {
List<Employee> countMaleFemaleEmpInSalesMarketing = employeeRep.findAll();

Map<String, Long> collect = countMaleFemaleEmpInSalesMarketing.stream()
.filter(te -> te.getDept().equals("Sales And Marketing"))
.collect(Collectors.groupingBy(Employee::getGender, Collectors.counting()));
return collect;

}

@GetMapping("/twelve")
public Map<String, Double> avgSalaryOfMaleAndFemaleEmployees() {
List<Employee> avgSalaryOfMaleAndFemaleEmp = employeeRep.findAll();

Map<String, Double> collect = avgSalaryOfMaleAndFemaleEmp.stream()
.collect(Collectors.groupingBy(Employee::getGender, Collectors.averagingDouble(Employee::getSalary)));
return collect;

}

@GetMapping("/thirteen")
public Map<String, List<String>> employeeListByDepartment() {
List<Employee> findAll = employeeRep.findAll();

Map<String, List<String>> collect = findAll.stream().collect(
Collectors.groupingBy(Employee::getDept, Collectors.mapping(Employee::getName, Collectors.toList())));

return collect;

}

@GetMapping("/fourteen")
public String employeeSalarySumAndAvg() {

List<Employee> empSalarySumAndAvg = employeeRep.findAll();

DoubleSummaryStatistics collect = empSalarySumAndAvg.stream()
.collect(Collectors.summarizingDouble(Employee::getSalary));

return "Total Salary = " + collect.getSum() + ", Average Salary = " + collect.getAverage();

}

@GetMapping("/fifteen")
public ResponseEntity<String> partitionEmployeesByAge() {
List<Employee> partitionEmployeesByAge25OldAnd25Young = employeeRep.findAll();

Map<Boolean, List<Employee>> collect = partitionEmployeesByAge25OldAnd25Young.stream()
.collect(Collectors.partitioningBy(te -> te.getAge() > 25));

Set<Entry<Boolean, List<Employee>>> entrySet = collect.entrySet();

String olderEmployeesResponse = "Employees older than 25 years: ";
String youngerEmployeesResponse = "Employees younger than or equal to 25 years: ";

for (Entry<Boolean, List<Employee>> entry : entrySet) {
List<Employee> list = entry.getValue();

for (Employee employee : list) {
String employeeName = employee.getName() + ", ";
if (entry.getKey()) {
olderEmployeesResponse += employeeName;
} else {
youngerEmployeesResponse += employeeName;
}
}
}

String finalResponse = olderEmployeesResponse + "\n" + youngerEmployeesResponse;

return ResponseEntity.ok(finalResponse);
}

@GetMapping("/sixteen")
public ResponseEntity<String> oldestEmployee() {

List<Employee> oldestEmp = employeeRep.findAll();
Optional<Employee> max = oldestEmp.stream().max(Comparator.comparing(Employee::getAge));

if (max.isPresent()) {
Employee employee = max.get();
String dept = employee.getDept();
int age = employee.getAge();

String response1 = "Department : " + dept;
String response2 = "Age : " + age;

String responseBody = response1 + "\n" + response2;

return ResponseEntity.ok(responseBody);
} else {
return ResponseEntity.notFound().build(); // Or any appropriate response for no employees found
}

}

@GetMapping("/seventeen")
public List<String> findAllEmpNamesStartWithA() {
List<Employee> findAll = employeeRep.findAll();

List<String> collect = findAll.stream().filter(te -> te.getName().startsWith("A")).map(Employee::getName)
.collect(Collectors.toList());

return collect;

}

@GetMapping("/eighteen")
public String findAllEmpDeptCount() {
List<Employee> findAll = employeeRep.findAll();

long count = findAll.stream().map(app -> app.getDept()).distinct().count();

return "Total Department : - " + count;

}

@GetMapping("/ninteen")
public String findAllEmpCount() {
List<Employee> allEmpCount = employeeRep.findAll();

Long count = allEmpCount.stream().collect(Collectors.counting());

return "Total Employees: " + count;

}

}

I can not use @RootXmlElement

"because I love Jason"🙃

nice comment

nice content

that is tricky . thanks for successfully video

Can you provide tutorials in Telugu step by step ...from spring framework

this is so cringe-worthy

Please Which app do you use for your screen recording?

i dont understand that why he have to talk about servlet in everything instead of the topic of the tutorial,.I was referring spring boot there also he lecture about servlet n all , then i switched to this here also the same thing, everybody here is not from software background here, Please understand this, I have learnt java only with the help of telusko, but while learning advance , its disturbing that he talks more about the topics which everybody might not understand

While running time showing (java.lang.ClassNotFoundException:jakarta.servlet.filter) but I have added related dependencies also still not solving the problem...

Thank you sir for this tutorial