About spring resttemplate timeout settings

• Spring org.springframework.web.client.RestTemplate 使用 org.springframework.http.client.SimpleClientHttpRequestFactory建立 java.net.HttpURLConnection
• The latter uses a default timeout configuration HttpURLConnection

HttpURLConnection Timeout property

ConnectTimeout(ms)

• a specified timeout value, in milliseconds, to be used when opening a communications link to the resource referenced by this URLConnection.
  
• If the timeout expires before the connection can be established, a java.net.SocketTimeoutException is raised. A timeout of zero is interpreted as an infinite timeout.

ReadTimeout(ms)

• a specified timeout, in milliseconds.
• A non-zero value specifies the timeout when reading from Input stream when a connection is established to a resource.
• If the timeout expires before there is data available for read, a java.net.SocketTimeoutException is raised.
• A timeout of zero is interpreted as an infinite timeout

RestTemplate timeout settings

Command Line Args (without modifying the code, configuration startup)

Covering HttpURLConnection default settings.

-Dsun.net.client.defaultConnectTimeout=<TimeoutInMiliSec>
-Dsun.net.client.defaultReadTimeout=<TimeoutInMiliSec>

Use SimpleClientHttpRequestFactory establish HttpURLConnection

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;

@Configuration
public class RestTemplateConfiguration {
    @Bean
    public RestTemplate restTemplate() throws KeyStoreException, NoSuchAlgorithmException, KeyManagementException {

        SimpleClientHttpRequestFactory clientHttpRequestFactory
                = new SimpleClientHttpRequestFactory();
        clientHttpRequestFactory.setConnectTimeout(10 * 1000);
        clientHttpRequestFactory.setReadTimeout(10 * 1000);
        return new RestTemplate(clientHttpRequestFactory);
    }
}

Use HttpComponentsClientHttpRequestFactory establish HttpURLConnection (recommended)

• org.springframework.http.client.HttpComponentsClientHttpRequestFactory
• HttpComponentsClientHttpRequestFactory constructor and setter methods for supporting custom configuration of org.apache.http.client.HttpClient
• Provided by the connection pool class construct HttpClient org.apache.http.impl.client.HttpClientBuilder.setConnectionManager (pollingConnectionManager) Method
• HttpClientBuilder.setDefaultRequestConfig set timeout
• HttpClientBuilder.setDefaultHeaders (headers) to set the default headers

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;

@Configuration
public class RestTemplateConfiguration {
    @Bean
    public RestTemplate restTemplate() throws KeyStoreException, NoSuchAlgorithmException, KeyManagementException {
        HttpComponentsClientHttpRequestFactory httpRequestFactory = new HttpComponentsClientHttpRequestFactory();
        httpRequestFactory.setConnectionRequestTimeout(30 * 1000);
        httpRequestFactory.setConnectTimeout(2 * 60 * 1000);
        httpRequestFactory.setReadTimeout(10 * 60 * 1000);
        return new RestTemplate(httpRequestFactory);
    }
}