Question

resttemplatebuilder 在哪个jar包

Answer 1

RestTemplate默认是使用SimpleClientHttpRequestFactory，内部是调用jdk的HttpConnection，默认超时为-1
@Autowired
RestTemplate simpleRestTemplate
@Autowired
RestTemplate restTemplate
基于jdk的spring的RestTemplate
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"
default-autowire="byName" default-lazy-init="true">

<!--方式一、使用jdk的实现-->
<bean id="ky.requestFactory" class="org.springframework.http.client.SimpleClientHttpRequestFactory">
<property name="readTimeout" value="10000"/>
<property name="connectTimeout" value="5000"/>
</bean>

<bean id="simpleRestTemplate" class="org.springframework.web.client.RestTemplate">
<constructor-arg ref="ky.requestFactory"/>
<property name="messageConverters">
<list>
<bean class="org.springframework.http.converter.FormHttpMessageConverter"/>
<bean class="org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter"/>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/plain;charset=UTF-8</value>
</list>
</property>
</bean>
</list>
</property>
</bean>

</beans>

使用Httpclient连接池的方式
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"
default-autowire="byName" default-lazy-init="true">

<!--方式二、使用httpclient的实现，带连接池-->
<bean id="ky.pollingConnectionManager" class="org.apache.http.impl.conn.PoolingHttpClientConnectionManager">
<!--整个连接池的并发-->
<property name="maxTotal" value="1000" />
<!--每个主机的并发-->
<property name="defaultMaxPerRoute" value="1000" />
</bean>

<bean id="ky.httpClientBuilder" class="org.apache.http.impl.client.HttpClientBuilder" factory-method="create">
<property name="connectionManager" ref="ky.pollingConnectionManager" />
<!--开启重试-->
<property name="retryHandler">
<bean class="org.apache.http.impl.client.DefaultHttpRequestRetryHandler">
<constructor-arg value="2"/>
<constructor-arg value="true"/>
</bean>
</property>
<property name="defaultHeaders">
<list>
<bean class="org.apache.http.message.BasicHeader">
<constructor-arg value="User-Agent"/>
<constructor-arg value="Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.16 Safari/537.36"/>
</bean>
<bean class="org.apache.http.message.BasicHeader">
<constructor-arg value="Accept-Encoding"/>
<constructor-arg value="gzip,deflate"/>
</bean>
<bean class="org.apache.http.message.BasicHeader">
<constructor-arg value="Accept-Language"/>
<constructor-arg value="zh-CN"/>
</bean>
</list>
</property>
</bean>

<bean id="ky.httpClient" factory-bean="ky.httpClientBuilder" factory-method="build" />

<bean id="ky.clientHttpRequestFactory" class="org.springframework.http.client.HttpComponentsClientHttpRequestFactory">
<constructor-arg ref="ky.httpClient"/>
<!--连接超时时间，毫秒-->
<property name="connectTimeout" value="5000"/>
<!--读写超时时间，毫秒-->
<property name="readTimeout" value="10000"/>
</bean>

<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
<constructor-arg ref="ky.clientHttpRequestFactory"/>
<property name="errorHandler">
<bean class="org.springframework.web.client.DefaultResponseErrorHandler"/>
</property>
<property name="messageConverters">
<list>
<bean class="org.springframework.http.converter.FormHttpMessageConverter"/>
<bean class="org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter"/>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/plain;charset=UTF-8</value>
</list>
</property>
</bean>
</list>
</property>
</bean>

</beans>

bean初始化+静态工具
线程安全的单例（懒汉模式）
基于jdk的spring的RestTemplate
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Lazy;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.http.converter.FormHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter;
import org.springframework.stereotype.Component;
import org.springframework.web.client.DefaultResponseErrorHandler;
import org.springframework.web.client.RestTemplate;

import javax.annotation.PostConstruct;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;

/**
* @title：基于jdk的spring的RestTemplate
* @author：liuxing
* @date：2015-05-18 09:35
*/
@Component
@Lazy(false)
public class SimpleRestClient {

private static final Logger LOGGER = LoggerFactory.getLogger(SimpleRestClient.class);

private static RestTemplate restTemplate;

static {
SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
requestFactory.setReadTimeout(5000);