简介
1、RestTemplate是spring支持的一个请求http rest服务的模板对象，性质上有点像jdbcTemplate。 2、RestTemplate底层还是使用的httpclient（org.apache.http.client.HttpClient）发送请求的。 3、HttpClient可以做连接池，而发送消息的工具类可以使用RestTemplate，所以如果你的项目需求http连接池，RestTemplate+httpclient连接池是一种不错的方式，可以节省开发工作，也可以更优雅的使用。
配置 1、maven依赖
<dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.5.6</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency>
2、Java配置类 在这里插入图片描述
httpConfig.properties：
http.maxTotal=500 http.defaultMaxPerRoute=300 #设置连接超时时间，单位毫秒 http.connectTimeout=10000 #http clilent中从connetcion pool中获得一个connection的超时时间,单位毫秒 http.connectionRequestTimeout=500 #请求获取数据的超时时间，单位毫秒。 如果访问一个接口，多少时间内无法返回数据，就直接放弃此次调用 http.socketTimeout=15000 http.staleConnectionCheckEnabled=true
java 代码：
import lombok.Data; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.context.annotation.PropertySource; import org.springframework.stereotype.Component;
/** * Created by qxr4383 on 2018/12/25. */ @Component @PropertySource(value= {"classpath:properties/httpConfig.properties"}) @ConfigurationProperties(prefix = "http.pool.conn") @Data public class HttpPoolProperties { private Integer maxTotal; private Integer defaultMaxPerRoute; private Integer connectTimeout; private Integer connectionRequestTimeout; private Integer socketTimeout; private Integer validateAfterInactivity; }
import org.apache.http.client.HttpClient; import org.apache.http.client.config.RequestConfig; import org.apache.http.config.Registry; import org.apache.http.config.RegistryBuilder; import org.apache.http.conn.socket.ConnectionSocketFactory; import org.apache.http.conn.socket.PlainConnectionSocketFactory; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.http.client.ClientHttpRequestFactory; import org.springframework.http.client.HttpComponentsClientHttpRequestFactory; import org.springframework.http.converter.HttpMessageConverter; import org.springframework.http.converter.StringHttpMessageConverter; import org.springframework.web.client.RestTemplate;
import java.nio.charset.StandardCharsets; import java.util.List;
/** * Created by qxr4383 on 2018/12/25. */ @Configuration public class RestTemplateConfig {
@Autowired private HttpPoolProperties httpPoolProperties;
@Bean public RestTemplate restTemplate() { RestTemplate restTemplate = new RestTemplate(httpRequestFactory()); List<HttpMessageConverter<?>> converterList = restTemplate.getMessageConverters();
//重新设置StringHttpMessageConverter字符集为UTF-8，解决中文乱码问题 HttpMessageConverter<?> converterTarget = null; for (HttpMessageConverter<?> item : converterList) { if (StringHttpMessageConverter.class == item.getClass()) { converterTarget = item; break; } } if (null != converterTarget) { converterList.remove(converterTarget); } converterList.add(1, new StringHttpMessageConverter(StandardCharsets.UTF_8)); return restTemplate; }
@Bean public ClientHttpRequestFactory httpRequestFactory() { return new HttpComponentsClientHttpRequestFactory(httpClient()); }
@Bean public HttpClient httpClient() { Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create() .register("http", PlainConnectionSocketFactory.getSocketFactory()) .register("https", SSLConnectionSocketFactory.getSocketFactory()) .build(); PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(registry); connectionManager.setMaxTotal(httpPoolProperties.getMaxTotal()); connectionManager.setDefaultMaxPerRoute(httpPoolProperties.getDefaultMaxPerRoute()); connectionManager.setValidateAfterInactivity(httpPoolProperties.getValidateAfterInactivity()); RequestConfig requestConfig = RequestConfig.custom() .setSocketTimeout(httpPoolProperties.getSocketTimeout()) //服务器返回数据(response)的时间，超过抛出read timeout .setConnectTimeout(httpPoolProperties.getConnectTimeout()) //连接上服务器(握手成功)的时间，超出抛出connect timeout .setConnectionRequestTimeout(httpPoolProperties.getConnectionRequestTimeout())//从连接池中获取连接的超时时间，超时间未拿到可用连接，会抛出org.apache.http.conn.ConnectionPoolTimeoutException: Timeout waiting for connection from pool .build(); return HttpClientBuilder.create() .setDefaultRequestConfig(requestConfig) .setConnectionManager(connectionManager) .build(); }
}
使用方法
直接获取ResponseEntity的body转换为你需要的对象即可
@Autowired private ObjectMapper objectMapper; @Autowired private RestTemplate restTemplate; @Override public WeatherApiPojo getWeather(String requestUrl) { WeatherApiPojo weatherApiPojo = new WeatherApiPojo(); try { logger.info("I'm going to send request: " + requestUrl);
ResponseEntity<String> responseEntity = restTemplate.getForEntity(requestUrl,String.class); if (responseEntity!=null && responseEntity.getStatusCodeValue()==200){ objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); weatherApiPojo = objectMapper.readValue(responseEntity.getBody(), WeatherApiPojo.class); } else { weatherApiPojo.setCode("-1"); } return weatherApiPojo; } catch (Exception e) { logger.error("获取第三方天气API接口getWeather error {} ", e); weatherApiPojo.setCode("-1"); } return weatherApiPojo; }
