Could not autowire field:RestTemplate in Spring boot application
SpringMavenSpring BootResttemplateSpring Problem Overview
I am getting below exception while running spring boot application during start up:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'testController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.web.client.RestTemplate com.micro.test.controller.TestController.restTemplate; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.client.RestTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
I am autowiring RestTemplate in my TestController. I am using Maven for dependency managagement.
TestMicroServiceApplication.java
package com.micro.test;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class TestMicroServiceApplication {
public static void main(String[] args) {
SpringApplication.run(TestMicroServiceApplication.class, args);
}
}
TestController.java
package com.micro.test.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
@RestController
public class TestController {
@Autowired
private RestTemplate restTemplate;
@RequestMapping(value="/micro/order/{id}",
method=RequestMethod.GET,
produces=MediaType.ALL_VALUE)
public String placeOrder(@PathVariable("id") int customerId){
System.out.println("Hit ===> PlaceOrder");
Object[] customerJson = restTemplate.getForObject("http://localhost:8080/micro/customers", Object[].class);
System.out.println(customerJson.toString());
return "false";
}
}
POM.xml
<?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.micro.test</groupId>
<artifactId>Test-MicroService</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>Test-MicroService</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Spring Solutions
Solution 1 - Spring
It's exactly what the error says. You didn't create any RestTemplate bean, so it can't autowire any. If you need a RestTemplate you'll have to provide one. For example, add the following to TestMicroServiceApplication.java:
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
Note, in earlier versions of the Spring cloud starter for Eureka, a RestTemplate bean was created for you, but this is no longer true.
Solution 2 - Spring
Depending on what technologies you're using and what versions will influence how you define a RestTemplate in your @Configuration class.
Spring >= 4 without Spring Boot
Simply define an @Bean:
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
Spring Boot <= 1.3
No need to define one, Spring Boot automatically defines one for you.
Spring Boot >= 1.4
Spring Boot no longer automatically defines a RestTemplate but instead defines a RestTemplateBuilder allowing you more control over the RestTemplate that gets created. You can inject the RestTemplateBuilder as an argument in your @Bean method to create a RestTemplate:
@Bean
public RestTemplate restTemplate(RestTemplateBuilder builder) {
// Do any additional configuration here
return builder.build();
}
Using it in your class
@Autowired
private RestTemplate restTemplate;
Solution 3 - Spring
If a TestRestTemplate is a valid option in your unit test, this documentation might be relevant
Short answer: if using
@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)
then @Autowired will work. If using
@SpringBootTest(webEnvironment=WebEnvironment.MOCK)
then create a TestRestTemplate like this
private TestRestTemplate template = new TestRestTemplate();
Solution 4 - Spring
- You must add
@Bean public RestTemplate restTemplate(RestTemplateBuilder builder){ return builder.build(); }
Solution 5 - Spring
> Since RestTemplate instances often need to be customized before being used, Spring Boot does not provide any single auto-configured RestTemplate bean.
RestTemplateBuilder offers proper way to configure and instantiate the rest template bean, for example for basic auth or interceptors.
@Bean
public RestTemplate restTemplate(RestTemplateBuilder builder) {
return builder
.basicAuthorization("user", "name") // Optional Basic auth example
.interceptors(new MyCustomInterceptor()) // Optional Custom interceptors, etc..
.build();
}
Solution 6 - Spring
you are trying to inject the restTemplate but you need to create configuration class . then there you need to create bean that return you new RestTemplate see the below example.
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class YourConfigClass {
@Bean
public RestTemplate restTesmplate() {
return new RestTemplate();
}
}
Solution 7 - Spring
Error points directly that RestTemplate bean is not defined in context and it cannot load the beans.
- Define a bean for RestTemplate and then use it
- Use a new instance of the RestTemplate
If you are sure that the bean is defined for the RestTemplate then use the following to print the beans that are available in the context loaded by spring boot application
ApplicationContext ctx = SpringApplication.run(Application.class, args);
String[] beanNames = ctx.getBeanDefinitionNames();
Arrays.sort(beanNames);
for (String beanName : beanNames) {
System.out.println(beanName);
}
If this contains the bean by the name/type given, then all good. Or else define a new bean and then use it.
Solution 8 - Spring
The simplest way I was able to achieve a similar feat to use the code below (reference), but I would suggest not to make API calls in controllers(SOLID principles). Also autowiring this way is better optimsed than the traditional way of doing it.
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
@RestController
public class TestController {
private final RestTemplate restTemplate;
@Autowired
public TestController(RestTemplateBuilder builder) {
this.restTemplate = builder.build();
}
@RequestMapping(value="/micro/order/{id}", method= RequestMethod.GET, produces= MediaType.ALL_VALUE)
public String placeOrder(@PathVariable("id") int customerId){
System.out.println("Hit ===> PlaceOrder");
Object[] customerJson = restTemplate.getForObject("http://localhost:8080/micro/customers", Object[].class);
System.out.println(customerJson.toString());
return "false";
}
}
Solution 9 - Spring
Please make sure two things:
1- Use @Bean annotation with the method.
@Bean
public RestTemplate restTemplate(RestTemplateBuilder builder){
return builder.build();
}
2- Scope of this method should be public not private.
Complete Example -
@Service
public class MakeHttpsCallImpl implements MakeHttpsCall {
@Autowired
private RestTemplate restTemplate;
@Override
public String makeHttpsCall() {
return restTemplate.getForObject("https://localhost:8085/onewayssl/v1/test",String.class);
}
@Bean
public RestTemplate restTemplate(RestTemplateBuilder builder){
return builder.build();
}
}