spring boot使用restTemplate调接口（一）

 

 

package org.suifeng.baseframework.api.rest;

import org.apache.http.client.HttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
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.client.SimpleClientHttpRequestFactory;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.client.RestOperations;
import org.springframework.web.client.RestTemplate;
import java.nio.charset.StandardCharsets;
import java.util.Iterator;
import java.util.List;

@Configuration
@ConditionalOnClass(value = {RestTemplate.class, HttpClient.class})
public class RestConfiguration {

    @Autowired
    private HttpRequestProperties httpRequestProperties;

    @Autowired
    private RestResponseErrorHandler restResponseErrorHandler;

    /**
     * 实例化RestTemplate对象
     */
    @Bean
    public RestTemplate restTemplate(){
        RestTemplate restTemplate = getRestTemplate();
        // 添加自定义请求头拦截器
//        restTemplate.setInterceptors(Collections.singletonList(headerRequestInterceptor));
        // 捕捉自定义的restException
        restTemplate.setErrorHandler(restResponseErrorHandler);
        return restTemplate;
    }

    /**
     * 创建HTTP客户端工厂
     */
    private ClientHttpRequestFactory createFactory() {
        if (httpRequestProperties.getMaxTotalConnect() <= 0) {
            SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
            factory.setConnectTimeout(httpRequestProperties.getConnectTimeout());
            factory.setReadTimeout(httpRequestProperties.getReadTimeout());
            return factory;
        }
        HttpClient httpClient = HttpClientBuilder.create().setMaxConnTotal(httpRequestProperties.getMaxTotalConnect())
                .setMaxConnPerRoute(httpRequestProperties.getMaxConnectPerRoute()).build();
        HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory(httpClient);
        factory.setConnectTimeout(httpRequestProperties.getConnectTimeout());
        factory.setReadTimeout(httpRequestProperties.getReadTimeout());
        return factory;
    }


    /**
     * 重新初始化MessageConverter
     */
    private void reInitMessageConverter(RestTemplate restTemplate) {
        List<HttpMessageConverter<?>> messageConverters = restTemplate.getMessageConverters();
        Iterator<HttpMessageConverter<?>> iterator = messageConverters.iterator();
        while (iterator.hasNext()) {
            HttpMessageConverter<?> converter = iterator.next();
            /*
             * RestTemplate会默认添加HttpMessageConverter，
             * 而添加的StringHttpMessageConverter默认使用的字符集是ISO-8859-1，
             * 在遇到中文的时候会有乱码，所以需要移除原有的StringHttpMessageConverter，修改字符集为UTF-8后重新设置。
             */
            if (converter instanceof StringHttpMessageConverter) {
                ((StringHttpMessageConverter) converter).setDefaultCharset(StandardCharsets.UTF_8);
            }
            /*
             * 由于MessageConverter消息转换器机制会判断"com.fasterxml.jackson.dataformat.xml.XmlMapper"是否存在，
             * 若存在则引入MappingJackson2XmlHttpMessageConverter，该消息转换器会优先于MappingJackson2HttpMessageConverter转换消息，
             * 导致调用接口返回xml格式，故要将其移除(或者降低其优先级)以返回json
             */
            if (converter instanceof MappingJackson2XmlHttpMessageConverter) {
                iterator.remove();
            }
        }
    }


    /**
     * 初始化RestTemplate,并加入spring的Bean工厂，由spring统一管理
     */
    public RestTemplate getRestTemplate() {
        RestTemplate restTemplate = new RestTemplate(this.createFactory());
        reInitMessageConverter(restTemplate);
        return restTemplate;
    }

}

package org.suifeng.baseframework.api.rest;

import lombok.Getter;
import lombok.Setter;
import org.springframework.stereotype.Component;

@Setter
@Getter
@Component
public class HttpRequestProperties {

    /**
     * 连接池的最大连接数默认为0
     */
    private int maxTotalConnect;

    /**
     * 单个主机的最大连接数
     */
    private int maxConnectPerRoute;

    /**
     * 连接超时默认2s
     */
    private int connectTimeout;

    /**
     * 读取超时默认30s
     */
    private int readTimeout;

}

package org.suifeng.baseframework.api.rest;

import org.suifeng.baseframework.api.common.exception.RestException;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.client.DefaultResponseErrorHandler;
import java.io.IOException;

@Slf4j
@Component
public class RestResponseErrorHandler extends DefaultResponseErrorHandler {

	/**
	 * 重写handleError，抛出RestException
	 */
	@Override
	public void handleError(ClientHttpResponse response) throws IOException {
		HttpStatus statusCode = HttpStatus.resolve(response.getRawStatusCode());
		log.debug("rest call has error: {}", statusCode.toString());
                // 获取服务端返回的异常信息，并抛出接口异常
                // 此处代码仅供参考
		String body = IOUtils.toString(response.getBody(),"UTF-8");
		throw new RestException(statusCode,body);
	}
	
}