how to do post request with raw data via spring rest template

Please try with this:

ResponseEntity<String> result = restTemplate.exchange(url, HttpMethod.POST, request, String.class);

Did u tried using postmaster and checked the output first. If its working then you can go for post or exchange method. exchange returns and post dont.

Since the RestTemplate class is a part of the Spring Web project, we only need spring-boot-starter-web dependency. Add the following dependency to your Gradle project's build.gradle file:

implementation 'org.springframework.boot:spring-boot-starter-web'

If you are using Maven, add the following dependency to your pom.xml file:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

RestService.java

@Service
public class RestService {

    private final RestTemplate restTemplate;

    public RestService(RestTemplateBuilder restTemplateBuilder) {
        this.restTemplate = restTemplateBuilder.build();
    }

    public String getPostsPlainJSON() {
        String url = "https://jsonplaceholder.typicode.com/posts";
        return this.restTemplate.getForObject(url, String.class);
    }
}

Post.java

public class Post implements Serializable {

    private int userId;
    private int id;
    private String title;
    private String body;

    // getters and setters
}

Now we can simply use the Post class as response type in getForObject() method:

public Post[] getPostsAsObject() {
    String url = "https://jsonplaceholder.typicode.com/posts";
    return this.restTemplate.getForObject(url, Post[].class);
}

nonrest/src/main/java/payroll/Employee.java

package payroll;

import java.util.Objects;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
class Employee {

  private @Id @GeneratedValue Long id;
  private String name;
  private String role;

  Employee() {}

  Employee(String name, String role) {

    this.name = name;
    this.role = role;
  }

  public Long getId() {
    return this.id;
  }

  public String getName() {
    return this.name;
  }

  public String getRole() {
    return this.role;
  }

  public void setId(Long id) {
    this.id = id;
  }

  public void setName(String name) {
    this.name = name;
  }

  public void setRole(String role) {
    this.role = role;
  }

  @Override
  public boolean equals(Object o) {

    if (this == o)
      return true;
    if (!(o instanceof Employee))
      return false;
    Employee employee = (Employee) o;
    return Objects.equals(this.id, employee.id) && Objects.equals(this.name, employee.name)
        && Objects.equals(this.role, employee.role);
  }

  @Override
  public int hashCode() {
    return Objects.hash(this.id, this.name, this.role);
  }

  @Override
  public String toString() {
    return "Employee{" + "id=" + this.id + ", name='" + this.name + '\'' + ", role='" + this.role + '\'' + '}';
  }
}

nonrest/src/main/java/payroll/EmployeeRepository.java

package payroll;

import org.springframework.data.jpa.repository.JpaRepository;

interface EmployeeRepository extends JpaRepository<Employee, Long> {

}

nonrest/src/main/java/payroll/PayrollApplication.java

package payroll;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class PayrollApplication {

  public static void main(String... args) {
    SpringApplication.run(PayrollApplication.class, args);
  }
}

nonrest/src/main/java/payroll/LoadDatabase.java

package payroll;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
class LoadDatabase {

  private static final Logger log = LoggerFactory.getLogger(LoadDatabase.class);

  @Bean
  CommandLineRunner initDatabase(EmployeeRepository repository) {

    return args -> {
      log.info("Preloading " + repository.save(new Employee("Bilbo Baggins", "burglar")));
      log.info("Preloading " + repository.save(new Employee("Frodo Baggins", "thief")));
    };
  }
}

Fragment of console output showing preloading of data

...
2018-08-09 11:36:26.169  INFO 74611 --- [main] payroll.LoadDatabase : Preloading Employee(id=1, name=Bilbo Baggins, role=burglar)
2018-08-09 11:36:26.174  INFO 74611 --- [main] payroll.LoadDatabase : Preloading Employee(id=2, name=Frodo Baggins, role=thief)
...