How to Solve 403 Error in Spring Boot Post Request

I am newbie in spring boot rest services. I have developed some rest api in spring boot using maven project.

I have successfully developed Get and Post Api. My GET Method working properly in postman and mobile. when i am trying to hit post method from postman its working properly but from mobile its gives 403 forbidden error.

This is my Configuration:

spring.datasource.url = jdbc:mysql://localhost/sampledb?useSSL=false
spring.datasource.username = te
spring.datasource.password = test
spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.MySQL5InnoDBDialect
Hibernate ddl auto (create, create-drop, validate, update)
spring.jpa.hibernate.ddl-auto = update

Please Suggest me how to solve error.

you have to disable csrf Protection because it is enabled by default in spring security: here you can see code that allow cors origin.

import org.springframework.context.annotation.Bean;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.CorsConfigurationSource;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;

@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter{

    @Override
    protected void configure(HttpSecurity http) throws Exception{
        http.cors().and().csrf().disable();
    }

    @Bean
    CorsConfigurationSource corsConfigurationSource() {
        CorsConfiguration configuration = new CorsConfiguration();
        configuration.setAllowedOrigins(Arrays.asList("*"));
        configuration.setAllowedMethods(Arrays.asList("*"));
        configuration.setAllowedHeaders(Arrays.asList("*"));
        configuration.setAllowCredentials(true);
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return source;
    }

}

Possible causes:

1. Requests done from postman are different to the one done from mobile (uri, method, headers)
2. Invalid token
3. CORS (read something about it, google is full of articles) add @CrossOrigin annotation to your controller.
4. mobile app is doing an OPTION request before performing the POST, and you block OPTION requests. If also from postman the OPTION requests are blocked, add the property spring.mvc.dispatch-options-request=true. Moreover, in case you are using spring security, you have to explicitly allow OPTION requests also for it.