SpringBoot學習8.1-RestTemplate請求rest風格後端

1.RestTemplate

RestTemplate的底層是通過HttpURLConnection實現的（注意:java.net.HttpURLConnection.setRequestMethod 不支持PATCH方法，無法將請求發送出去）。參考文章

訪問已經創建好的rest風格後端。這裏使用SpringBoot學習8.0-創建REST風格站點介紹的後端代碼。

2.RestTemplate使用

用RestTemplate調用一下方法：

• GET請求：postForObject()
• POST請求：getForObject()、getForEntity()
• PUT請求：put()
• PATCH請求：不支持
• DELETE請求：delete()

舉例說明：

其中http://localhost:9001/是啓動的用戶微服務ip和端口。

package com.zyf.appserver.user;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.client.RestTemplate;
@Controller
@ResponseBody // 請求結果默認轉換爲json
public class UserController {
	// rest請求模板
	RestTemplate restTemplate = new RestTemplate();

	@RequestMapping("/insert")
	public User insert(@RequestBody User user) {
		HttpHeaders headers = new HttpHeaders();
		HttpEntity<User> reqeust = new HttpEntity<>(user, headers);
		// post請求
		return restTemplate.postForObject("http://localhost:9001/userRestController/user", reqeust, User.class);
	}
	@RequestMapping(value = "/getUser/{id}")
	public User getUser(@PathVariable int id) {
		// get請求
		return restTemplate.getForObject("http://localhost:9001/userRestController/user/{id}", User.class, id);
	}
	@SuppressWarnings({ "rawtypes", "unchecked" })
	@RequestMapping("/getUsers/{id}/{name}")
	public List<User> getUsers(@PathVariable String id, @PathVariable String name) {
		Map<String, Object> param = new HashMap<String, Object>();
		param.put("id", id);
		param.put("name", name);
		// get請求
		ResponseEntity<List> responseEntity = restTemplate
				.getForEntity("http://localhost:9001/userRestController" + "/user/{id}/{name}", List.class, param);
		List<User> users = responseEntity.getBody();
		return users;
	}
	@RequestMapping("/update/{id}") // 更新全部屬性
	public User update(@PathVariable int id, @RequestBody User user) {
		HttpHeaders headers = new HttpHeaders();
		HttpEntity<User> reqeust = new HttpEntity<>(user, headers);
		// put請求
		restTemplate.put("http://localhost:9001/userRestController/user/{id}", reqeust, id);
		return user;
	}
	@RequestMapping("/updatepatch/{id}/{name}/{note}") // 更新部分屬性
	public User updatepatch(@PathVariable int id, @PathVariable String name, @PathVariable String note) {
		Map<String, Object> param = new HashMap<String, Object>();
		param.put("id", id);
		param.put("name", name);
		param.put("note", note);
		HttpHeaders headers = new HttpHeaders();
		HttpEntity<Map<String, Object>> reqeust = new HttpEntity<>(param, headers);
		// patch請求
		// RestTemplate的底層是通過HttpURLConnection實現的（注意:java.net.HttpURLConnection.setRequestMethod
		// 不支持PATCH方法，無法將請求發送出去）。
		return restTemplate.patchForObject("http://localhost:9001/userRestController/user/{id}/{name}/{note}", reqeust,
				User.class, param);
	}
	@RequestMapping("/delete")
	public User delete(int id) {
		// delete請求
		restTemplate.delete("http://localhost:9001/userRestController/user/{id}", id);
		return new User(1, "吉姆格林", 1, "rest風格，刪除");
	}
}

 

github:https://github.com/zhangyangfei/spring-cloud-learn.git 中的cloud-parent工程。