RestTemplate是Spring提供的用于訪問(wèn)Rest服務(wù)的客戶端，
RestTemplate提供了多種便捷訪問(wèn)遠(yuǎn)程Http服務(wù)的方法,能夠大大提高客戶端的編寫效率。
調(diào)用RestTemplate的默認(rèn)構(gòu)造函數(shù)，RestTemplate對(duì)象在底層通過(guò)使用java.net包下的實(shí)現(xiàn)創(chuàng)建HTTP 請(qǐng)求，
可以通過(guò)使用ClientHttpRequestFactory指定不同的HTTP請(qǐng)求方式。
ClientHttpRequestFactory接口主要提供了兩種實(shí)現(xiàn)方式
1、一種是SimpleClientHttpRequestFactory，使用J2SE提供的方式（既java.net包提供的方式）創(chuàng)建底層的Http請(qǐng)求連接。
2、一種方式是使用HttpComponentsClientHttpRequestFactory方式，底層使用HttpClient訪問(wèn)遠(yuǎn)程的Http服務(wù)，使用HttpClient可以配置連接池和證書等信息。
默認(rèn)的 RestTemplate 有個(gè)機(jī)制是請(qǐng)求狀態(tài)碼非200 就拋出異常，會(huì)中斷接下來(lái)的操作。如果不想中斷對(duì)結(jié)果數(shù)據(jù)得解析，可以通過(guò)覆蓋默認(rèn)的 ResponseErrorHandler ，見(jiàn)下面的示例，示例中的方法中基本都是空方法，只要對(duì)hasError修改下，讓他一直返回true，即是不檢查狀態(tài)碼及拋異常了。
package com.example.demo.web.config;
import java.io.IOException;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.ResponseErrorHandler;
import org.springframework.web.client.RestTemplate;
@Configuration
public class RestTemplateConfig {
@Bean
public RestTemplate restTemplate(ClientHttpRequestFactory factory) throws Exception {
RestTemplate restTemplate = new RestTemplate(factory);
ResponseErrorHandler responseErrorHandler = new ResponseErrorHandler() {
@Override
public boolean hasError(ClientHttpResponse clientHttpResponse) throws IOException {
return true;
}
@Override
public void handleError(ClientHttpResponse clientHttpResponse) throws IOException {
}
};
restTemplate.setErrorHandler(responseErrorHandler);
return restTemplate;
}
@Bean
public ClientHttpRequestFactory simpleClientHttpRequestFactory(){
SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
//讀取超時(shí)5秒
factory.setReadTimeout(5000);
//連接超時(shí)15秒
factory.setConnectTimeout(15000);
return factory;
}
}
RestTemppate運(yùn)用實(shí)例
package com.example.demo.web.controller;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import com.example.demo.domain.Book;
@RestController
public class TestBookController {
private Logger logger = LoggerFactory.getLogger(getClass());
@Autowired
private RestTemplate restTemplate;
@GetMapping("/testaddbook")
public Book testAddBook() {
Book book = new Book();
ResponseEntity<Book> responseEntity = restTemplate.postForEntity( "http://localhost:8061/book", book , Book.class);
return responseEntity.getBody();
}
}
其他方法，catch
HttpStatusCodeException ,
e.getResponseBodyAsString()try {
ResponseEntity<Component> response = restTemplate.exchange(webSvcURL,
HttpMethod.POST,
requestEntity,
Component.class);
} catch (HttpStatusCodeException e) {
List<String> customHeader = e.getResponseHeaders().get("x-app-err-id");
String svcErrorMessageID = "";
if (customHeader != null) {
svcErrorMessageID = customHeader.get(0);
}
throw new CustomException(e.getMessage(), e, svcErrorMessageID);
// You can get the body too but you will have to deserialize it yourself
// e.getResponseBodyAsByteArray()
// e.getResponseBodyAsString()
}
https://stackoverflow.com/questions/7878002/resttemplate-handling-response-headers-body-in-exceptions-restclientexceptionhttps://stackoverflow.com/questions/38093388/spring-resttemplate-exception-handling/51805956#51805956