get與post兩種方式的區別:對於本次主題而言,最顯著的區別就是get請求方式參數是在url後,而post請求方式的參數是在request body中。因此兩者獲取參數的方式也大不一樣。
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
public class User implements Serializable {
private static final long serialVersionUID = 1L;
@JsonProperty(value = "id")
private Integer id;
@JsonProperty(value = "name")
private String name;
@JsonProperty(value = "age")
private Integer age;
@JsonProperty(value = "hobby")
private List<String> hobby;
}
Get方式參數的獲取
-
直接在方法體中指定參數
@GetMapping("/get")
public User getUserById(Integer id) {
if (id.intValue() == 0) {
return null;
}
return list.get(id);
}
使用requestParam
@GetMapping("/get")
public User getUserById(@RequestParam(name = "id", required = true) Integer id) {
if (id.intValue() == 0) {
return null;
}
return list.get(id);
}
其中RequestParam中name表示url中請求的字段名,當required爲true時,表示該參數必填;defaultValue表示當該參數沒有傳遞數據時給出的默認值,如defaultvalue=”0”
訪問方式同上
使用PathVariable
@GetMapping("/get/{id}")
public User getUserByPathValue(@PathVariable(name = "id", required = true) Integer id) {
return list.get(id);
}
該方式用來獲取路徑中的參數。@PathVariable中的字段含義同RequestParam
訪問http:///ip:port/xx/get/1 ——->對應於get/{id}
使用HttpServletRequest
@GetMapping("/get")
public User getUserById(HttpServletRequest request) {
Integer id = Integer.parseInt(request.getParameter("id"));
if (id.intValue() == 0) {
return null;
}
return list.get(id);
}
POST方式參數的獲取
一般而言,post形式的參數被放在請求體中以application/json的形式被後端獲取
獲取一個對象
content-type:application/json
@PostMapping("/save")
public User saveUser(@RequestBody User user) {
list.add(user);
return user;
}
會把這些字段組裝到對象中
使用Map
map中存放的鍵值對就對應於json中的鍵值對 content-type:application/json
@PostMapping("/save")
public User saveUser(@RequestBody Map<String, Object> map) {
Integer id = (Integer) map.get("id");
String name = (String) map.get("name");
Integer age = (Integer) map.get("age");
List<String> hobby=(List<String>) map.get("hobby");
User user = new User(id, name, age, hobby);
list.add(user);
return user;
}
使用HttpServletRequest
將content-type改爲x-www-form-urlencoded
@PostMapping("/save")
public User save(HttpServletRequest request) {
Integer id = Integer.parseInt(request.getParameter("id"));
String name = request.getParameter("name");
Integer age = Integer.parseInt(request.getParameter("age"));
String parameter = request.getParameter("hobby");
User user = new User(id, name, age, null);
list.add(user);
return user;
}
-
-
通過HTTP協議將參數轉換爲JSONObject
content-type:application/json
@PostMapping("/save")
public User save(HttpServletRequest request) throws IOException, JSONException {
JSONObject jsonObject = handlerData(request);
Integer id = jsonObject.getInteger("id");
String name = jsonObject.getString("name");
Integer age = jsonObject.getInteger("age");
List<String> hobby = jsonObject.getObject("hobby", List.class);
User user = new User(id, name, age, hobby);
list.add(user);
return user;
}
//這裏使用的是alibaba的json工具類
public static JSONObject handlerData(HttpServletRequest request) throws IOException, JSONException {
StringBuffer sb = new StringBuffer();
InputStream is = request.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is, "utf-8"));
String s = "";
while ((s = br.readLine()) != null) {
sb.append(s);
}
if (sb.toString().length() <= 0) {
return null;
} else {
return JSONObject.parseObject(sb.toString());
}
}
本來使用的是org.json包下的JSONObject,無奈啓動就報 org.json.JSONException,後改爲使用alibaba的fastjson
注意:使用緩衝輸入流讀取的是這裏的json,因此是一行一行讀取的:
!
讀取的時候 報出異常:not close json text,token:: 將json改爲如下所示