Spring Boot实现跨系统接口调用

osc_0kdyznad 2021-01-21 09:06:17
Spring Boot maven fastjson HttpClient


Spring Boot实现跨系统接口调用

一、概述

在开发过程中经常会需要和其他系统进行对接,或者调用一些外部的第三方接口来获取所需要的数据信息,这个时候我们就需要跨系统去调用接口,本文基于spring boot项目整理三种方案。
1、使用httpClient请求;
2、使用RestTemplate方法;
3、使用Fegin进行消费;


1、使用httpClient请求

需要先在maven的pom.xml中添加httpClient依赖

<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</dependency>
public class HttpClient {
/**
* get 请求
* @return
*/
public static String doHttpGet(String url, List<NameValuePair> params){
String result = null;
//1.获取httpclient
CloseableHttpClient httpClient = HttpClients.createDefault();
//接口返回结果
CloseableHttpResponse response = null;
String paramStr = null;
try {
paramStr = EntityUtils.toString(new UrlEncodedFormEntity(params));
//拼接参数
StringBuffer sb = new StringBuffer();
sb.append(url);
sb.append("?");
sb.append(paramStr);
//2.创建get请求
HttpGet httpGet = new HttpGet(sb.toString());
//3.设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(2000).setConnectTimeout(2000).build();
httpGet.setConfig(requestConfig);
/*此处可以添加一些请求头信息,例如:
httpGet.addHeader("content-type","text/xml");*/
//4.提交参数
response = httpClient.execute(httpGet);
//5.得到响应信息
int statusCode = response.getStatusLine().getStatusCode();
//6.判断响应信息是否正确
if(HttpStatus.SC_OK != statusCode){
//终止并抛出异常
httpGet.abort();
throw new RuntimeException("HttpClient,error status code :" + statusCode);
}
//7.转换成实体类
HttpEntity entity = response.getEntity();
if(null != entity){
result = EntityUtils.toString(entity);
}
EntityUtils.consume(entity);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
//8.关闭所有资源连接
if(null != response){
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(null != httpClient){
try {
httpClient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return result;
}
/**
* http post 请求
*/
public static String doPost(String url, List<NameValuePair> params){
String result = null;
//1. 获取httpclient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;
try {
//2. 创建post请求
HttpPost httpPost = new HttpPost(url);
//3.设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(2000).setConnectTimeout(2000).build();
httpPost.setConfig(requestConfig);
//4.提交参数发送请求
UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(params);
/*此处可以设置传输时的编码格式,和数据格式
urlEncodedFormEntity.setContentEncoding("UTF-8");
urlEncodedFormEntity.setContentType("application/json");*/
httpPost.setEntity(urlEncodedFormEntity);
response = httpClient.execute(httpPost);
//5.得到响应信息
int statusCode = response.getStatusLine().getStatusCode();
//6. 判断响应信息是否正确
if(HttpStatus.SC_OK != statusCode){
//结束请求并抛出异常
httpPost.abort();
throw new RuntimeException("HttpClient,error status code :" + statusCode);
}
//7. 转换成实体类
HttpEntity entity = response.getEntity();
if(null != entity){
result = EntityUtils.toString(entity,"UTF-8");
}
EntityUtils.consume(entity);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
//8. 关闭所有资源连接
if(null != response){
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(null != httpClient){
try {
httpClient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return result;
}
}
public class Test {
public static void main(String[] args) {
String url = "https://restapi.amap.com/v3/ip";
List<NameValuePair> list = new ArrayList<>();
list.add(new BasicNameValuePair("key","075b6eddd825148a674dfa8a8558****"));
String resultGet = HttpClient.doHttpGet(url,list);
System.out.println("get请求" + resultGet);
String resultPost = HttpClient.doPost(url,list);
System.out.println("post请求" + resultPost);
}
}

2、使用RestTemplate方法

此处就用使用get和post请求。
2.1 get请求:
有getForObject(…)和getForEntity(…)两个方法都可以进行请求调用,区别在于,getForObject(…)是直接返回预期的对象,即返回体中的body对象,而getForEntity(…)则是返回ResponseEntity 封装类,里面包含HTTP请求的头信息对象。

public class Test {
public static void main(String[] args) {
RestTemplate restTemplate = new RestTemplate();
//方法一:getForEntity(String var1, Class<T> var2),没有参数
String url = "https://restapi.amap.com/v3/ip?key=075b6eddd825148a674dfa8a8558ac62";
String trans = restTemplate.getForObject(url,String.class);
System.out.println(trans);
//方法一:getForEntity(String var1, Class<T> var2, Object... var3),url中用占位符,传入参数
//该方法提供了三个参数,其中var1为请求的地址(即url),var2为请求响应body的包装类型,var3为url中的参数绑定
url = "https://restapi.amap.com/v3/ip?key={?}";
trans = restTemplate.getForObject(url,String.class,"075b6eddd825148a674dfa8a8558ac62");
System.out.println(trans);
//方法二:getForEntity(String var1, Class<T> var2, Map<String, ?> var3),map传参
url = "https://restapi.amap.com/v3/ip?key={key}";
Map<String,Object> map = new HashMap<>();
map.put("key","075b6eddd825148a674dfa8a8558ac62");
trans = restTemplate.getForObject(url,String.class,map);
System.out.println(trans);
//方法三:getForEntity(URI var1, Class<T> var2),uri传参
URI uri = URI.create("https://restapi.amap.com/v3/ip?key=075b6eddd825148a674dfa8a8558ac62");
trans = restTemplate.getForObject(uri,String.class);
System.out.println(trans);
}
}

3、使用Fegin进行消费(推荐)

3.1 首先需要在maven项目的pom.xml中添加fegin依赖。如果需要用JSON传递,也要引入JSON相关的依赖,本文使用alibaba的fastjson依赖

<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
<version>2.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>RELEASE</version>
</dependency>

3.2 在service层编写用来消费的接口

@FeignClient(url = "${map.url}",name = "mapurl")
public interface GaoDeMapService {
@RequestMapping(value = "/v3/ip",method = RequestMethod.GET)
JSONObject getMap(@RequestParam("ip") String ip,
@RequestParam("key") String key);
}

此处@FeignClient表中这是消费者,url中的${map.url}是配置在application.properties中的IP地址和端口号

server.port=8010
map.url = https://restapi.amap.com

RequestMapping中的 “/v3/ip”表示被调用的服务端的接口地址名称;
method表中请求的方式:get或者post都可以;

3.3 在Spring Boot启动类上添加注释@EnableFeignClients,开启fegin

@SpringBootApplication
@EnableFeignClients
public class TransportApplication {
public static void main(String[] args) {
SpringApplication.run(TransportApplication.class, args);
}
}

3.4 在代码中调用接口即可
本文是以调用高德地图API为例

@RestController
public class TestController {
@Autowired
GaoDeMapService gaoDeMapService;
@RequestMapping("/test2")
public JSONObject test2( String ip,String key){
return gaoDeMapService.getMap(ip,key);
}
}

 

版权声明
本文为[osc_0kdyznad]所创,转载请带上原文链接,感谢
https://my.oschina.net/u/4406404/blog/4917169

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