代码优化

2023-02-02 15:35:02 +08:00
parent 7b8fedacbd
commit 57e8f17e6e
8 changed files with 81 additions and 70 deletions
--- a/.idea/.gitignore
+++ b/.idea/.gitignore
@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
--- a/src/main/java/com/tarzan/recommend/RecommendSystemApplication.java
+++ b/src/main/java/com/tarzan/recommend/RecommendSystemApplication.java
@@ -1,8 +1,7 @@
 package com.tarzan.recommend;

-import com.tarzan.recommend.Service.Recommend;
+import com.tarzan.recommend.service.Recommend;
 import com.tarzan.recommend.dto.ItemDTO;
-import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;

 import java.util.List;
--- a/src/main/java/com/tarzan/recommend/core/CoreMath.java
+++ b/src/main/java/com/tarzan/recommend/core/CoreMath.java
@@ -12,49 +12,57 @@ import java.util.stream.IntStream;
 *
 * @author tarzan
 * @version 1.0
- * @company 洛阳图联科技有限公司
- * @copyright (c) 2019 LuoYang TuLian Co'Ltd Inc. All rights reserved.
 * @date 2020/7/31$ 15:21$
 * @since JDK1.8
 */
 public class CoreMath {

+    /**
+     * 方法描述: 推荐电影id列表
+     *
+     * @param userId 当前用户
+     * @param list 用户电影评分数据
+     * @return {@link List<Integer>}
+     * @date 2023年02月02日 14:51:42
+     */
    public List<Integer> recommend(Integer userId, List<RelateDTO> list) {
-        //找到最近邻用户id
-        Map<Double, Integer> distances = computeNearestNeighbor(userId, list);
-        Integer nearest = distances.values().iterator().next();
-
+        //按用户分组
        Map<Integer, List<RelateDTO>>  userMap=list.stream().collect(Collectors.groupingBy(RelateDTO::getUseId));
-
+        //获取其他用户与当前用户的关系值
+        Map<Double, Integer> distances = computeNeighbor(userId, userMap);
+        //取关系最近的用户
+        Integer nearestUserId = distances.values().iterator().next();
        //最近邻用户看过电影列表
-        List<Integer>  neighborItemList = userMap.get(nearest).stream().map(e->e.getModuleId()).collect(Collectors.toList());
+        List<Integer>  neighborItems = userMap.get(nearestUserId).stream().map(RelateDTO::getModuleId).collect(Collectors.toList());
        //指定用户看过电影列表
-        List<Integer>  userItemList  = userMap.get(userId).stream().map(e->e.getModuleId()).collect(Collectors.toList());;
+        List<Integer>  userItems  = userMap.get(userId).stream().map(RelateDTO::getModuleId).collect(Collectors.toList());

        //找到最近邻看过，但是该用户没看过的电影，计算推荐，放入推荐列表
        List<Integer> recommendList = new ArrayList<>();
-        for (Integer item : neighborItemList) {
-            if (!userItemList.contains(item)) {
+        for (Integer item : neighborItems) {
+            if (!userItems.contains(item)) {
                recommendList.add(item);
            }
        }
-        Collections.sort(recommendList);
+       // Collections.sort(recommendList);
        return recommendList;
    }


    /**
     * 在给定userId的情况下，计算其他用户和它的相关系数并排序
-     * @param userId
-     * @param list
-     * @return
+     * @param userId 用户id
+     * @param userMap 用户电影评分关系mqp
+     * @return Map<Double, Integer>
     */
-    private Map<Double, Integer> computeNearestNeighbor(Integer userId, List<RelateDTO> list) {
-        Map<Integer, List<RelateDTO>>  userMap=list.stream().collect(Collectors.groupingBy(RelateDTO::getUseId));
+    private Map<Double, Integer> computeNeighbor(Integer userId, Map<Integer,List<RelateDTO>>  userMap) {
        Map<Double, Integer> distances = new TreeMap<>();
+        List<RelateDTO> userItems=userMap.get(userId);
        userMap.forEach((k,v)->{
-            if(k!=userId){
-                double distance = pearson_dis(v,userMap.get(userId));
+            //排除此用户
+            if(!k.equals(userId)){
+                //关系距离
+                double distance = pearsonDis(v,userItems);
                distances.put(distance, k);
            }
        });
@@ -65,16 +73,16 @@ public class CoreMath {
    /**
     * 计算两个序列间的相关系数
     *
-     * @param xList
-     * @param yList
-     * @return
+     * @param xList 用户1喜欢的电影
+     * @param yList 用户2喜欢的电影
+     * @return double
     */
-    private double pearson_dis(List<RelateDTO> xList, List<RelateDTO> yList) {
+    private double pearsonDis(List<RelateDTO> xList, List<RelateDTO> yList) {
        List<Integer> xs= Lists.newArrayList();
        List<Integer> ys= Lists.newArrayList();
        xList.forEach(x->{
            yList.forEach(y->{
-                if(x.getModuleId()==y.getModuleId()){
+                if(x.getModuleId().equals(y.getModuleId())){
                    xs.add(x.getIndex());
                    ys.add(y.getIndex());
                }
@@ -86,14 +94,13 @@ public class CoreMath {
    /**
     * 方法描述: 皮尔森（pearson）相关系数计算
     *
-     * @param xs
-     * @param ys 
-     * @Return {@link Double}
-     * @throws 
+     * @param xs x集合
+     * @param ys y集合
+     * @Return {@link double}
     * @author tarzan
     * @date 2020年07月31日 17:03:20
     */
-    public static Double getRelate(List<Integer> xs, List<Integer>  ys){
+    public static double getRelate(List<Integer> xs, List<Integer> ys){
        int n=xs.size();
        double Ex= xs.stream().mapToDouble(x->x).sum();
        double Ey=ys.stream().mapToDouble(y->y).sum();
@@ -102,7 +109,9 @@ public class CoreMath {
        double Exy= IntStream.range(0,n).mapToDouble(i->xs.get(i)*ys.get(i)).sum();
        double numerator=Exy-Ex*Ey/n;
        double denominator=Math.sqrt((Ex2-Math.pow(Ex,2)/n)*(Ey2-Math.pow(Ey,2)/n));
-        if (denominator==0) return 0.0;
+        if (denominator==0) {
+            return 0D;
+        }
        return numerator/denominator;
    }

--- a/src/main/java/com/tarzan/recommend/dto/ItemDTO.java
+++ b/src/main/java/com/tarzan/recommend/dto/ItemDTO.java
@@ -7,10 +7,8 @@ import lombok.NoArgsConstructor;
 /**
 * 业务项
 *
- * @author liu yapeng
+ * @author TARZAN
 * @version 1.0
- * @company 洛阳图联科技有限公司
- * @copyright (c) 2019 LuoYang TuLian Co'Ltd Inc. All rights reserved.
 * @date 2020/7/31$ 15:02$
 * @since JDK1.8
 */
@@ -18,9 +16,13 @@ import lombok.NoArgsConstructor;
@NoArgsConstructor
@AllArgsConstructor
 public class ItemDTO {
+    /** 主键 */
    private Integer id;
+    /** 名称 */
    private String name;
+    /** 日期 */
    private String date;
+    /** 链接 */
    private String link;

 }
--- a/src/main/java/com/tarzan/recommend/dto/RelateDTO.java
+++ b/src/main/java/com/tarzan/recommend/dto/RelateDTO.java
@@ -7,10 +7,8 @@ import lombok.NoArgsConstructor;
 /**
 * 关系数据
 *
- * @author liu yapeng
+ * @author tarzan
 * @version 1.0
- * @company 洛阳图联科技有限公司
- * @copyright (c) 2019 LuoYang TuLian Co'Ltd Inc. All rights reserved.
 * @date 2020/7/31$ 14:51$
 * @since JDK1.8
 */
@@ -18,11 +16,11 @@ import lombok.NoArgsConstructor;
@AllArgsConstructor
@NoArgsConstructor
 public class RelateDTO {
-    //用户id
+    /** 用户id */
    private Integer useId;
-    //业务id
+    /** 业务id */
    private Integer moduleId;
-    //指数
+    /** 指数 */
    private Integer index;


--- a/src/main/java/com/tarzan/recommend/dto/UserDTO.java
+++ b/src/main/java/com/tarzan/recommend/dto/UserDTO.java
@@ -7,7 +7,7 @@ import lombok.NoArgsConstructor;
 /**
 * 用户对象
 *
- * @author liu yapeng
+ * @author TARZAN
 * @version 1.0
 * @company 洛阳图联科技有限公司
 * @copyright (c) 2019 LuoYang TuLian Co'Ltd Inc. All rights reserved.
@@ -18,15 +18,15 @@ import lombok.NoArgsConstructor;
@AllArgsConstructor
@NoArgsConstructor
 public class UserDTO {
-    //主键
+    /** 主键 */
    private Integer id;
-    //年纪
+    /** 年纪 */
    private Integer age;
-    //性别
+    /** 性别 */
    private String sex;
-    //职业
+    /** 职业 */
    private String profession;
-    //邮编
+    /** 邮编 */
    private String postcode;

 }
--- a/src/main/java/com/tarzan/recommend/service/FileDataSource.java
+++ b/src/main/java/com/tarzan/recommend/service/FileDataSource.java
@@ -1,4 +1,4 @@
-package com.tarzan.recommend.Service;
+package com.tarzan.recommend.service;

 import com.tarzan.recommend.dto.ItemDTO;
 import com.tarzan.recommend.dto.RelateDTO;
@@ -10,7 +10,11 @@ import org.assertj.core.util.Lists;
 import java.io.*;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
+import java.util.Objects;

+/**
+ * @author tarzan
+ */
@Data
@Slf4j
 public class FileDataSource {
@@ -22,20 +26,18 @@ public class FileDataSource {
    /**
     * 方法描述: 读取基础数据
     *
-     * @param
     * @Return {@link List<RelateDTO>}
-     * @throws
     * @author tarzan
     * @date 2020年07月31日 16:53:40
     */
    public static List<RelateDTO> getData() {
-        folderPath=new FileDataSource().getClass().getResource("/ml-100k").getPath();
+        folderPath= Objects.requireNonNull(FileDataSource.class.getResource("/ml-100k")).getPath();
        List<RelateDTO> relateList = Lists.newArrayList();
        try {
            FileInputStream out = new FileInputStream(folderPath+"\\u.data");
            InputStreamReader reader = new InputStreamReader(out, StandardCharsets.UTF_8);
            BufferedReader in = new BufferedReader(reader);
-            String line = null;
+            String line;
            while ((line = in.readLine()) != null) {
                String newline = line.replaceAll("[\t]", " ");
                String[] ht = newline.split(" ");
@@ -54,20 +56,18 @@ public class FileDataSource {
    /**
     * 方法描述: 读取用户数据
     *
-     * @param
     * @Return {@link List<UserDTO>}
-     * @throws
     * @author tarzan
     * @date 2020年07月31日 16:54:51
     */
    public static List<UserDTO> getUserData() {
-        folderPath=new FileDataSource().getClass().getResource("/ml-100k").getPath();
+        folderPath= Objects.requireNonNull(FileDataSource.class.getResource("/ml-100k")).getPath();
        List<UserDTO> userList = Lists.newArrayList();
        try {
            FileInputStream out = new FileInputStream(folderPath+"\\u.user");
            InputStreamReader reader = new InputStreamReader(out, StandardCharsets.UTF_8);
            BufferedReader in = new BufferedReader(reader);
-            String line = null;
+            String line;
            while ((line = in.readLine()) != null) {
                String newline = line.replaceAll("[\t]", " ");
                String[] ht = newline.split("\\|");
@@ -89,20 +89,18 @@ public class FileDataSource {
    /**
     * 方法描述: 读取电影数据
     *
-     * @param
     * @Return {@link List<ItemDTO>}
-     * @throws
     * @author tarzan
     * @date 2020年07月31日 16:54:22
     */
    public static List<ItemDTO> getItemData() {
-        folderPath=new FileDataSource().getClass().getResource("/ml-100k").getPath();
+        folderPath= Objects.requireNonNull(FileDataSource.class.getResource("/ml-100k")).getPath();
        List<ItemDTO> itemList = Lists.newArrayList();
        try {
            FileInputStream out = new FileInputStream(folderPath+"\\u.item");
            InputStreamReader reader = new InputStreamReader(out, StandardCharsets.UTF_8);
            BufferedReader in = new BufferedReader(reader);
-            String line = null;
+            String line;
            while ((line = in.readLine()) != null) {
                String newline = line.replaceAll("[\t]", " ");
                String[] ht = newline.split("\\|");
--- a/src/main/java/com/tarzan/recommend/service/Recommend.java
+++ b/src/main/java/com/tarzan/recommend/service/Recommend.java
@@ -1,4 +1,4 @@
-package com.tarzan.recommend.Service;
+package com.tarzan.recommend.service;

 import com.tarzan.recommend.core.CoreMath;
 import com.tarzan.recommend.dto.ItemDTO;
@@ -10,9 +10,8 @@ import java.util.stream.Collectors;
 /**
 * 推荐服务
 *
- * @author liu yapeng
+ * @author TARZAN
 * @version 1.0
- * @copyright (c) 2019 LuoYang TuLian Co'Ltd Inc. All rights reserved.
 * @date 2020/7/31$ 16:18$
 * @since JDK1.8
 */
@@ -21,9 +20,8 @@ public class Recommend{
    /**
     * 方法描述: 猜你喜欢
     *
-     * @param
+     * @param userId 用户id
     * @Return {@link List<ItemDTO>}
-     * @throws
     * @author tarzan
     * @date 2020年07月31日 17:28:06
     */
@@ -31,8 +29,7 @@ public class Recommend{
        CoreMath coreMath = new CoreMath();
        List<RelateDTO> data= FileDataSource.getData();
        List<Integer> recommendations = coreMath.recommend(userId, data);
-        List<ItemDTO> itemList= FileDataSource.getItemData().stream().filter(e->recommendations.contains(e.getId())).collect(Collectors.toList());
-        return itemList;
+        return FileDataSource.getItemData().stream().filter(e->recommendations.contains(e.getId())).collect(Collectors.toList());
    }