完成了主窗口和增删改查

src/backend/service/impl/QuestionsService.java

@@ -0,0 +1,48 @@
+package backend.service.impl;
+
+import backend.dao.impl.QuestionsDao;
+import backend.model.Questions;
+import backend.model.enums.GlobalData;
+
+import java.util.List;
+import java.util.Vector;
+
+public class QuestionsService {
+    private QuestionsDao questionsDao = new QuestionsDao();
+    private Vector<Vector<String>> commonHandler(List<Questions> questionsList){
+        //加工数据 把数据库查到的List转成Vector<Vector<>>
+        Vector<Vector<String>> questionsData = new Vector<>();
+        if(questionsList != null) {
+            for (Questions questionsPo : questionsList) {
+                Vector<String> row = new Vector<>();
+                row.add(String.valueOf(questionsPo.getId()));
+                row.add(questionsPo.getName());
+                row.add(questionsPo.getDescription());
+                row.add(questionsPo.getAnswer());
+                row.add(GlobalData.FREQUENCY_MAP.get(questionsPo.getFrequency()));
+                questionsData.add(row);
+            }
+        }
+        return questionsData;
+    }
+    public Vector<Vector<String>> getAll(){
+        //从数据库中获取所有单词
+        List<Questions> questionsList = questionsDao.getAll();
+        //把List转成表格所需的格式
+        return commonHandler(questionsList);
+        //返回给前端
+    }
+
+    public Vector<Vector<String>> getByCondition(Integer frequency,String key){
+        //从数据库中获取所有单词
+        List<Questions> wordPoList = questionsDao.getByCondition(frequency,key);
+        //把List转成表格所需的格式
+        return commonHandler(wordPoList);
+    }
+    public boolean insert(Questions question){
+        return questionsDao.insert(question);
+    }
+    public void delete(Integer id){
+        questionsDao.delete(id);
+    }
+}