Failed to create autwire: RestTemplate field in Spring boot application

Question

During startup, when loading the spring application during startup, the following exception is thrown:

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 run RestTemplate in my TestController. I use Maven for dependency management.

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> 

Answer 1

This is exactly what the error says. You have not created a single RestTemplate bean, so it cannot auto-detect. If you need a RestTemplate , you will need to provide one. For example, add the following to TestMicroServiceApplication.java :

 @Bean public RestTemplate restTemplate() { return new RestTemplate(); } 

Please note that in earlier versions of Spring cloud starter for Eureka, a RestTemplate bean was created for you, but this is no longer the case.

Answer 2

Depending on which technologies you use and which versions will affect how you define RestTemplate in your @Configuration class.

Spring> = 4 without Spring Boot

Just define @Bean :

 @Bean public RestTemplate restTemplate() { return new RestTemplate(); } 

Spring boot <= 1.3

There is no need to define it, Spring Boot automatically detects it 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 created RestTemplate. You can RestTemplateBuilder as an argument to your @Bean method to create a RestTemplate :

 @Bean public RestTemplate restTemplate(RestTemplateBuilder builder) { // Do any additional configuration here return builder.build(); } 

Using it in class

 @Autowired private RestTemplate restTemplate; 

Link

Answer 3

If TestRestTemplate is a valid parameter in your unit test, this documentation may be relevant.

http://docs.spring.io/spring-boot/docs/1.4.1.RELEASE/reference/htmlsingle/#boot-features-rest-templates-test-utility

Short answer: when using

 @SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT) 

then @Autowired will work. Using

 @SpringBootTest(webEnvironment=WebEnvironment.MOCK) 

then create a TestRestTemplate like this

 private TestRestTemplate template = new TestRestTemplate(); 

Answer 4

The error indicates that the RestTemplate bean is not defined in the context and cannot load beans.

• Define a bean for RestTemplate and then use
• Use a new instance of RestTemplate

If you are sure that a bean is defined for the RestTemplate template, print beans that are available in the context downloaded by spring to download

use the following:

 ApplicationContext ctx = SpringApplication.run(Application.class, args); String[] beanNames = ctx.getBeanDefinitionNames(); Arrays.sort(beanNames); for (String beanName : beanNames) { System.out.println(beanName); } 

If it contains a bean by name / type, then all is well. Or else define a new bean and then use it.

Answer 5

Since RestTemplate instances often need to be configured before use, Spring Boot does not provide any automatic RestTemplate bean configuration.

RestTemplateBuilder offers the right way to configure and create a bean break pattern, 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(); } 

Answer 6

Please make sure two things:

1- Use the @Bean annotation with the method.

 @Bean public RestTemplate restTemplate(RestTemplateBuilder builder){ return builder.build(); } 

2- The scope of this method should be public, not private .

Full 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(); } }