Autowire bean from @Configuration

Question

I am new to Spring, I am getting the exception "No qualifying bean of type [int] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}". When i try the below approach.

This is the configuration for the RestTemplate

@Configuration
public class RestClientConfig {

@Bean
public ObjectMapper getObjMapper(){
return new ObjectMapper();
}

@Bean
public RestTemplate createRestTemplate(int maxTotalConn, int maxPerChannel, int connTimout) {
    PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
    connectionManager.setMaxTotal(maxTotalConn);
    connectionManager.setDefaultMaxPerRoute(maxPerChannel);

    RequestConfig config = RequestConfig.custom().setConnectTimeout(connTimout).build();
    CloseableHttpClient httpClient = HttpClientBuilder.create().setConnectionManager(connectionManager)
            .setDefaultRequestConfig(config).build();
    ClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory(httpClient);

    RestTemplate restTemplate = new RestTemplate(factory);

    restTemplate.setErrorHandler(new RestResponseErrorHandler());
    restTemplate.setMessageConverters(createMessageConverters());

    return restTemplate;
}

private List<HttpMessageConverter<?>> createMessageConverters() {
    List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
    MappingJackson2HttpMessageConverter jsonMessageConverter = new MappingJackson2HttpMessageConverter();
    jsonMessageConverter.setObjectMapper( getObjMapper());
    messageConverters.add(jsonMessageConverter);
    return messageConverters;
}

}

When i try to access like this, it causing the exception mentioned above.

@Autowired
private RestClientConfig restTemplate;

ResponseEntity<String> response2 = restTemplate.createRestTemplate(100, 100, 100).exchange( url, HttpMethod.GET, entity , String.class );

Please can some one help and point me the correct approach and what i am doing anything wrong?

Answer 1

You need to inject the RestTemplate, not the config class

@Autowired
private RestTemplate restTemplate;

instead of:

@Autowired
private RestClientConfig restTemplate;

EDIT

Here is one way to pass your arguments to your class:

//EXAMPLE @Value("${propFile.maxTotalConn}")


@Bean
public RestTemplate createRestTemplate(@Value("${propFile.maxTotalConn}") int maxTotalConn, @Value("${propFile.maxPerChannel}") int maxPerChannel, connTimoutint connTimout) {
   PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
   connectionManager.setMaxTotal(maxTotalConn);
   connectionManager.setDefaultMaxPerRoute(maxPerChannel);

  ...
}

EXPLANATION

Create a properties file (*.properties) and place in your src/main/resources folder. Include your properties in it as the code above suggests. @Value is a Spring annotation that searches for the properties file on the classpath and injects the values while creating your Spring bean.