feat: 🎸 课程列表按最新\最热\推荐排序

jeecg-boot/jeecg-boot-module/jeecg-module-learn/src/main/java/org/jeecg/modules/biz/controller/CourseBizController.java

@@ -33,8 +33,8 @@ import org.jeecg.modules.gen.resource.entity.Resource;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
+import java.util.Comparator;
 
-import javax.annotation.PostConstruct;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -55,8 +55,27 @@ public class CourseBizController {
     public Result<List<CourseWithTeacherInfo>> queryCourseList(
             @RequestParam(value = "categoryId", required = false) String categoryId,
             @RequestParam(value = "difficulty", required = false) String difficulty,
-            @RequestParam(value = "subject", required = false) String topic) {
+            @RequestParam(value = "subject", required = false) String topic,
+            @RequestParam(value = "sort", required = false) String sort) {
         List<CourseWithTeacherInfo> list = courseBizService.getCourseList(categoryId, difficulty, topic);
+        if (sort != null) {
+            switch (sort) {
+                case "hottest":
+                    list = list.stream()
+                        .sorted(Comparator.comparing(Course::getEnrollCount, Comparator.nullsLast(Integer::compareTo)).reversed())
+                        .collect(Collectors.toList());
+                    break;
+                case "latest":
+                    list = list.stream()
+                        .sorted(Comparator.comparing(Course::getCreateTime, Comparator.nullsLast(java.util.Date::compareTo)).reversed())
+                        .collect(Collectors.toList());
+                    break;
+                case "recommend":
+                default:
+                    // 不处理，直接返回
+                    break;
+            }
+        }
         return Result.OK(list);
     }