add notification API

GET /notification
DELETE /notification
POST /notification/read

Change-Id: I06f28ce188049015cb6a0fe221caf2f784687db5
diff --git a/src/main/java/com/g9/g9backend/pojo/Notification.java b/src/main/java/com/g9/g9backend/pojo/Notification.java
index 7ebf7c1..249eb7e 100644
--- a/src/main/java/com/g9/g9backend/pojo/Notification.java
+++ b/src/main/java/com/g9/g9backend/pojo/Notification.java
@@ -2,6 +2,7 @@
 
 import com.baomidou.mybatisplus.annotation.IdType;
 import com.baomidou.mybatisplus.annotation.TableId;
+import com.fasterxml.jackson.annotation.JsonProperty;
 import lombok.*;
 
 import java.util.Date;
@@ -21,14 +22,13 @@
 
     private int userId;
 
-    private String type;
-
     private String title;
 
     private String content;
 
     private Date createAt;
 
+    @JsonProperty("isRead")
     private boolean isRead;
 
     private int triggeredBy;
diff --git a/src/main/java/com/g9/g9backend/pojo/Thread.java b/src/main/java/com/g9/g9backend/pojo/Thread.java
index ddcea67..a69fb82 100644
--- a/src/main/java/com/g9/g9backend/pojo/Thread.java
+++ b/src/main/java/com/g9/g9backend/pojo/Thread.java
@@ -29,8 +29,6 @@
 
     private int likes;
 
-    private boolean isLike;
-
     private Date createAt;
 
     private int commentNumber;
diff --git a/src/main/java/com/g9/g9backend/pojo/ThreadLike.java b/src/main/java/com/g9/g9backend/pojo/ThreadLike.java
new file mode 100644
index 0000000..6818ed4
--- /dev/null
+++ b/src/main/java/com/g9/g9backend/pojo/ThreadLike.java
@@ -0,0 +1,18 @@
+package com.g9.g9backend.pojo;
+
+import com.github.jeffreyning.mybatisplus.anno.MppMultiId;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class ThreadLike {
+
+    @MppMultiId
+    private int userId;
+
+    @MppMultiId
+    private int threadId;
+}