:::section{.abstract}
## Overview
The web/presentation tier is the user interface and communication layer of the application, where the end-user interacts with the application using the HTTP protocol. Its main purpose is to display and collect information from the user. Web presentation tiers are usually developed using HTML, CSS, and JavaScript on the front end and a set of controllers on the back end.
:::

:::section{.main}
## Create Controllers
Creating a controller layer is simple using spring boot. We can directly focus on the action if we know the right annotation.
We need two controllers. 
1) An employee controller - Contains mapping allowed for employee 
2) An admin controller - Contains mapping allowed for admin.

### EmployeeController
Let's write `EmployeeController` first. 
```java
@RestController
@RequestMapping("/employee")
public class EmployeeController {

    private EmployeeService employee service;

    @Autowired
    public void setEmployeeService(EmployeeService employeeService) {
        this.employeeService = employeeService;
    }

    @GetMapping(value = "/{id}")
    public EmployeeBO getMyDetails(@PathVariable("id") String empId) {
        return employeeService.fetchEmployee(empId);
    }

    @PutMapping(value = "/{id}")
    public EmployeeBO updateDetails(@PathVariable("id") String empId, @RequestBody EmployeeBO newDetails) {
        return employeeService.updateEmployee(empId, newDetails);
    }
}

```

**EmployeeControllerTest**
```java
@ExtendWith(SpringExtension.class)
@WebMvcTest(controllers = EmployeeController.class)
class EmployeeControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private EmployeeService employee service;

    @Autowired
    private ObjectMapper objectMapper;

    @Test
    void testGetEmployee_success() throws Exception {
        String emp_id = "EMP-12345";
        EmployeeBO employeeBO = new EmployeeBO();
        employeeBO.setFirstName("Tony");
        employeeBO.setLastName("Stark");
        employeeBO.setEmployeeId(emp_id);
        employeeBO.setEmail("tony.stark@mail.com");
        Mockito.when(employeeService.fetchEmployee(emp_id)).thenReturn(employeeBO);

        MvcResult mvcResult = mockMvc.perform(get("/employee/{id}", "EMP-12345")).andExpect(status().isOk()).andReturn();
        assertEquals(objectMapper.writeValueAsString(employeeBO), mvcResult.getResponse().getContentAsString());
    }

    @Test
    void testGetEmployee_employeeNotFound() throws Exception {
        String emp_id = "EMP-12345";
        EmployeeBO employeeBO = new EmployeeBO();
        employeeBO.setFirstName("Tony");
        employeeBO.setLastName("Stark");
        employeeBO.setEmployeeId(emp_id);
        employeeBO.setEmail("tony.stark@mail.com");
        Mockito.when(employeeService.fetchEmployee(emp_id)).thenThrow(EmployeeNotFoundException.class);
        mockMvc.perform(get("/employee/{id}", "EMP-12345")).andExpect(status().is(404));
    }

    @Test
    void testUpdateEmployee_success() throws Exception {
        String emp_id = "EMP-12345";
        EmployeeBO employeeBO = new EmployeeBO();
        employeeBO.setFirstName("Tony");
        employeeBO.setLastName("Stark");
        employeeBO.setEmail("tony.stark@mail.com");

        Mockito.when(employeeService.updateEmployee(emp_id,employeeBO)).thenReturn(employeeBO);
        MvcResult mvcResult = mockMvc.perform(put("/employee/{id}", "EMP-12345").contentType(MediaType.APPLICATION_JSON).content(objectMapper.writeValueAsString(employeeBO))).andExpect(status().is(200)).andReturn();
        assertEquals(objectMapper.writeValueAsString(employeeBO), mvcResult.getResponse().getContentAsString());
    }
}
```
:::
:::section{.main}
## AdminController
Admin can perform the additional task of creating, deleting, and searching employees.
```java
@RestController
@RequestMapping("/admin/employee")
public class AdminController {

    private EmployeeService employee service;

    @Autowired
    public void setEmployeeService(EmployeeService employeeService) {
        this.employeeService = employeeService;
    }

    @PostMapping
    public EmployeeBO createNew(@RequestBody EmployeeBO employeeBO) {
        return employeeService.saveEmployee(employeeBO);
    }

    @DeleteMapping(value = "/{id}")
    public void delete(@PathVariable("id") String empId) {
        employeeService.deleteEmployeeById(empId);
    }

    @GetMapping("/search")
    public List<EmployeeBO> search(@RequestParam("firstNameStartsWith") String firstNameStartsWith) {
        return employeeService.searchEmployeeByFirstName(firstNameStartsWith);
    }
}

```

**AdminControllerTest**
```java
@ExtendWith(SpringExtension.class)
@WebMvcTest(controllers = AdminController.class)
class AdminControllerTest {
    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private EmployeeService employeeService;

    @Autowired
    private ObjectMapper objectMapper;

    @Test
    void test_create_employee() throws Exception {
        EmployeeBO employeeBO = new EmployeeBO();
        employeeBO.setFirstName("Tony");
        employeeBO.setLastName("Stark");
        employeeBO.setEmail("tony.stark@mail.com");

        Mockito.when(employeeService.saveEmployee(employeeBO)).thenReturn(employeeBO);
        MvcResult mvcResult = mockMvc.perform(post("/admin/employee/").contentType(MediaType.APPLICATION_JSON).content(objectMapper.writeValueAsString(employeeBO))).andExpect(status().is(201)).andReturn();
        assertEquals(objectMapper.writeValueAsString(employeeBO), mvcResult.getResponse().getContentAsString());
    }

    @Test
    void test_delete_employee() throws Exception {
        String empToDelete= "EMP-12345";

        Mockito.doNothing().when(employeeService).deleteEmployeeById(empToDelete);
        MvcResult mvcResult = mockMvc.perform(delete("/admin/employee/{id}",empToDelete).contentType(MediaType.APPLICATION_JSON)).andExpect(status().is(200)).andReturn();
    }
}
```

:::
:::section{.main}
## Testing Using Postman
We will now run the application and verify the endpoints.
Currently, we don't have any employees in our database.
```java
mysql> select * from employees;
Empty set (0.01 sec)

mysql>
```
We will operate in the order of Create, Read, Update, Search and delete.
### Create New Employee
![Create New Employee](https://www.scaler.com/topics/images/create-new-employee.webp)

```plaintext
mysql> select * from employees;
+----+---------------+--------------+------------+-----------+
| id | email         | employee_id  | first_name | last_name |
+----+---------------+--------------+------------+-----------+
|  4 | t.s@gmail.com | EMP-10000497 | tony       | stark     |
+----+---------------+--------------+------------+-----------+
1 row in set (0.00 sec)
```
An employee is created with employee id `EMP-10000497`.
### Get an Employee
![Get an Employee](https://www.scaler.com/topics/images/get-an-employee.webp)

### Update an Employee
![Update an Employee](https://www.scaler.com/topics/images/update-an-employee.webp)

```plaintext
mysql> select * from employees;
+----+------------------+--------------+------------+-----------+
| id | email            | employee_id  | first_name | last_name |
+----+------------------+--------------+------------+-----------+
|  4 | tony.s@gmail.com | EMP-10000497 | tony       | stark     |
+----+------------------+--------------+------------+-----------+
1 row in set (0.00 sec)
```
The employee is updated with the new email address.

### Search Employee
Search employees with a first name starting with "To".
![Search Employee](https://www.scaler.com/topics/images/search-employee.webp)

### Delete an Employee
Should delete record in DB.
![Delete an Employee](https://www.scaler.com/topics/images/delete-an-employee.webp)

```plaintext
mysql> select * from employees;
Empty set (0.01 sec)

mysql> select * from employees;
+----+---------------+--------------+------------+-----------+
| id | email         | employee_id  | first_name | last_name |
+----+---------------+--------------+------------+-----------+
|  4 | t.s@gmail.com | EMP-10000497 | tony       | stark     |
+----+---------------+--------------+------------+-----------+
1 row in set (0.00 sec)

mysql> select * from employees;
+----+------------------+--------------+------------+-----------+
| id | email            | employee_id  | first_name | last_name |
+----+------------------+--------------+------------+-----------+
|  4 | tony.s@gmail.com | EMP-10000497 | tony       | stark     |
+----+------------------+--------------+------------+-----------+
1 row in set (0.00 sec)

mysql> select * from employees;
Empty set (0.00 sec)

mysql>
```

The source code is available in the GitHub repository and postman collection under tag number [version_6.0.0](https://github.com/paliwalarpan/scalerems/releases/tag/version_6.0.0 "{rel=noopener nofollow}").
:::
:::section{.summary}
## Conclusion
In this article, we covered
* Building a web layer for the employee management system.
* Unit testing web layer by mocking the service layer fully.
* Verified all our endpoints using postman.

:::

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This article by Scaler Topics covers the Rest Controller class of Employee Management application using Spring Boot and Spring Data JPA integration.

Employee Management System Web Layer | Employee Management Application Using Spring Boot and Spring Data JPA Integration - Scaler Topics

Worked with many companies from startup to fortune 500 companies, where he held roles as a software engineer, technical lead, application architect & solution architect. His expertise is mainly in building high performance application.

Arpan

---
title: Employee Management System Web Layer | Employee Management Application Using Spring Boot and Spring Data JPA Integration - Scaler Topics
description: This article by Scaler Topics covers the Rest Controller class of Employee Management application using Spring Boot and Spring Data JPA integration.
category: Spring Boot
author: Arpan Paliwal
---
:::section{.abstract}
## Overview
The web/presentation tier is the user interface and communication layer of the application, where the end-user interacts with the application using the HTTP protocol. Its main purpose is to display and collect information from the user. Web presentation tiers are usually developed using HTML, CSS, and JavaScript on the front end and a set of controllers on the back end.
:::

:::section{.main}
## Create Controllers
Creating a controller layer is simple using spring boot. We can directly focus on the action if we know the right annotation.
We need two controllers. 
1) An employee controller - Contains mapping allowed for employee 
2) An admin controller - Contains mapping allowed for admin.

### EmployeeController
Let's write `EmployeeController` first. 
```java
@RestController
@RequestMapping("/employee")
public class EmployeeController {

    private EmployeeService employee service;

    @Autowired
    public void setEmployeeService(EmployeeService employeeService) {
        this.employeeService = employeeService;
    }

    @GetMapping(value = "/{id}")
    public EmployeeBO getMyDetails(@PathVariable("id") String empId) {
        return employeeService.fetchEmployee(empId);
    }

    @PutMapping(value = "/{id}")
    public EmployeeBO updateDetails(@PathVariable("id") String empId, @RequestBody EmployeeBO newDetails) {
        return employeeService.updateEmployee(empId, newDetails);
    }
}

```

**EmployeeControllerTest**
```java
@ExtendWith(SpringExtension.class)
@WebMvcTest(controllers = EmployeeController.class)
class EmployeeControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private EmployeeService employee service;

    @Autowired
    private ObjectMapper objectMapper;

    @Test
    void testGetEmployee_success() throws Exception {
        String emp_id = "EMP-12345";
        EmployeeBO employeeBO = new EmployeeBO();
        employeeBO.setFirstName("Tony");
        employeeBO.setLastName("Stark");
        employeeBO.setEmployeeId(emp_id);
        employeeBO.setEmail("tony.stark@mail.com");
        Mockito.when(employeeService.fetchEmployee(emp_id)).thenReturn(employeeBO);

        MvcResult mvcResult = mockMvc.perform(get("/employee/{id}", "EMP-12345")).andExpect(status().isOk()).andReturn();
        assertEquals(objectMapper.writeValueAsString(employeeBO), mvcResult.getResponse().getContentAsString());
    }

    @Test
    void testGetEmployee_employeeNotFound() throws Exception {
        String emp_id = "EMP-12345";
        EmployeeBO employeeBO = new EmployeeBO();
        employeeBO.setFirstName("Tony");
        employeeBO.setLastName("Stark");
        employeeBO.setEmployeeId(emp_id);
        employeeBO.setEmail("tony.stark@mail.com");
        Mockito.when(employeeService.fetchEmployee(emp_id)).thenThrow(EmployeeNotFoundException.class);
        mockMvc.perform(get("/employee/{id}", "EMP-12345")).andExpect(status().is(404));
    }

    @Test
    void testUpdateEmployee_success() throws Exception {
        String emp_id = "EMP-12345";
        EmployeeBO employeeBO = new EmployeeBO();
        employeeBO.setFirstName("Tony");
        employeeBO.setLastName("Stark");
        employeeBO.setEmail("tony.stark@mail.com");

        Mockito.when(employeeService.updateEmployee(emp_id,employeeBO)).thenReturn(employeeBO);
        MvcResult mvcResult = mockMvc.perform(put("/employee/{id}", "EMP-12345").contentType(MediaType.APPLICATION_JSON).content(objectMapper.writeValueAsString(employeeBO))).andExpect(status().is(200)).andReturn();
        assertEquals(objectMapper.writeValueAsString(employeeBO), mvcResult.getResponse().getContentAsString());
    }
}
```
:::
:::section{.main}
## AdminController
Admin can perform the additional task of creating, deleting, and searching employees.
```java
@RestController
@RequestMapping("/admin/employee")
public class AdminController {

    private EmployeeService employee service;

    @Autowired
    public void setEmployeeService(EmployeeService employeeService) {
        this.employeeService = employeeService;
    }

    @PostMapping
    public EmployeeBO createNew(@RequestBody EmployeeBO employeeBO) {
        return employeeService.saveEmployee(employeeBO);
    }

    @DeleteMapping(value = "/{id}")
    public void delete(@PathVariable("id") String empId) {
        employeeService.deleteEmployeeById(empId);
    }

    @GetMapping("/search")
    public List<EmployeeBO> search(@RequestParam("firstNameStartsWith") String firstNameStartsWith) {
        return employeeService.searchEmployeeByFirstName(firstNameStartsWith);
    }
}

```

**AdminControllerTest**
```java
@ExtendWith(SpringExtension.class)
@WebMvcTest(controllers = AdminController.class)
class AdminControllerTest {
    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private EmployeeService employeeService;

    @Autowired
    private ObjectMapper objectMapper;

    @Test
    void test_create_employee() throws Exception {
        EmployeeBO employeeBO = new EmployeeBO();
        employeeBO.setFirstName("Tony");
        employeeBO.setLastName("Stark");
        employeeBO.setEmail("tony.stark@mail.com");

        Mockito.when(employeeService.saveEmployee(employeeBO)).thenReturn(employeeBO);
        MvcResult mvcResult = mockMvc.perform(post("/admin/employee/").contentType(MediaType.APPLICATION_JSON).content(objectMapper.writeValueAsString(employeeBO))).andExpect(status().is(201)).andReturn();
        assertEquals(objectMapper.writeValueAsString(employeeBO), mvcResult.getResponse().getContentAsString());
    }

    @Test
    void test_delete_employee() throws Exception {
        String empToDelete= "EMP-12345";

        Mockito.doNothing().when(employeeService).deleteEmployeeById(empToDelete);
        MvcResult mvcResult = mockMvc.perform(delete("/admin/employee/{id}",empToDelete).contentType(MediaType.APPLICATION_JSON)).andExpect(status().is(200)).andReturn();
    }
}
```

:::
:::section{.main}
## Testing Using Postman
We will now run the application and verify the endpoints.
Currently, we don't have any employees in our database.
```java
mysql> select * from employees;
Empty set (0.01 sec)

mysql>
```
We will operate in the order of Create, Read, Update, Search and delete.
### Create New Employee
![Create New Employee](https://www.scaler.com/topics/images/create-new-employee.webp)

```plaintext
mysql> select * from employees;
+----+---------------+--------------+------------+-----------+
| id | email         | employee_id  | first_name | last_name |
+----+---------------+--------------+------------+-----------+
|  4 | t.s@gmail.com | EMP-10000497 | tony       | stark     |
+----+---------------+--------------+------------+-----------+
1 row in set (0.00 sec)
```
An employee is created with employee id `EMP-10000497`.
### Get an Employee
![Get an Employee](https://www.scaler.com/topics/images/get-an-employee.webp)

### Update an Employee
![Update an Employee](https://www.scaler.com/topics/images/update-an-employee.webp)

```plaintext
mysql> select * from employees;
+----+------------------+--------------+------------+-----------+
| id | email            | employee_id  | first_name | last_name |
+----+------------------+--------------+------------+-----------+
|  4 | tony.s@gmail.com | EMP-10000497 | tony       | stark     |
+----+------------------+--------------+------------+-----------+
1 row in set (0.00 sec)
```
The employee is updated with the new email address.

### Search Employee
Search employees with a first name starting with "To".
![Search Employee](https://www.scaler.com/topics/images/search-employee.webp)

### Delete an Employee
Should delete record in DB.
![Delete an Employee](https://www.scaler.com/topics/images/delete-an-employee.webp)

```plaintext
mysql> select * from employees;
Empty set (0.01 sec)

mysql> select * from employees;
+----+---------------+--------------+------------+-----------+
| id | email         | employee_id  | first_name | last_name |
+----+---------------+--------------+------------+-----------+
|  4 | t.s@gmail.com | EMP-10000497 | tony       | stark     |
+----+---------------+--------------+------------+-----------+
1 row in set (0.00 sec)

mysql> select * from employees;
+----+------------------+--------------+------------+-----------+
| id | email            | employee_id  | first_name | last_name |
+----+------------------+--------------+------------+-----------+
|  4 | tony.s@gmail.com | EMP-10000497 | tony       | stark     |
+----+------------------+--------------+------------+-----------+
1 row in set (0.00 sec)

mysql> select * from employees;
Empty set (0.00 sec)

mysql>
```

The source code is available in the GitHub repository and postman collection under tag number [version_6.0.0](https://github.com/paliwalarpan/scalerems/releases/tag/version_6.0.0 "{rel=noopener nofollow}").
:::
:::section{.summary}
## Conclusion
In this article, we covered
* Building a web layer for the employee management system.
* Unit testing web layer by mocking the service layer fully.
* Verified all our endpoints using postman.

:::

Learn about Employee Management System Web Layer.