小修改

src/main/java/jty/expressdistributionsystem/DTO/SendMessageDTO.java

@@ -4,8 +4,10 @@ import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
 import lombok.Data;
 
+import java.io.Serializable;
+
 @Data
-public class SendMessageDTO {
+public class SendMessageDTO implements Serializable {
     @JsonSerialize(using = ToStringSerializer.class)
     private Long Id;
 

src/main/java/jty/expressdistributionsystem/controller/AdminController.java

@@ -56,7 +56,7 @@ public class AdminController {
     @DeleteMapping("/delete/{id}")
     public Result<String> delete(@PathVariable Long id, @RequestParam @NotNull String operation) {
         User user = userService.getById(id);
-        if(user == null) {
+        if (user == null) {
             return new Result<>(401, "账号不存在", "");
         }
         switch (operation) {
@@ -77,12 +77,6 @@ public class AdminController {
     // 管理员发送消息
     @PostMapping("/sendMessage")
     public Result<String> sendMessage(@RequestBody @NotNull SendMessageDTO sendMessageDTO) {
-        LambdaQueryWrapper<User> userLambdaQueryWrapper = new LambdaQueryWrapper<>();
-        userLambdaQueryWrapper.eq(User::getId, sendMessageDTO.getId());
-        User user = userService.getOne(userLambdaQueryWrapper);
-        if(user == null) {
-            return new Result<>(404, "用户不存在", "");
-        }
         Message message = SendMessageUtil.sendMessage(sendMessageDTO);
         messageService.save(message);
         return new Result<>(200, "发送成功", "");
@@ -96,7 +90,7 @@ public class AdminController {
         List<ExpressListDTO> expressListDTOList = new ArrayList<>();
         // 获取所有的快递记录
         List<Records> recordsList = recordsService.list();
-        for(Records records : recordsList) {
+        for (Records records : recordsList) {
             Goods goods = goodsService.getById(records.getGoodsId());
             // 查询寄件人、收件人、签收者、快递员信息
             User sender = userService.getById(records.getSendUserId());