初步完成底层的数据操作，项目结构初显

主要修改：
- 完成蔬菜数据类(Vegetable.java)
- 完成统一响应类(UnityResponse.java, ResponseTool.java，名字可能会改)
- 完成底层的数据处理类(Tools.java，名字也可能会改，ResponseProcessor.java)
- 新增部分异常类(me.lensfrex.vegetables.exceptions)
- 小改IOUtil的注释
当然还不能跑 ~~(就算跑起来了也是bug一大坨吧(超小声))~~

.idea/runConfigurations/vegetables.xml

@@ -0,0 +1,12 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="vegetables" type="Application" factoryName="Application">
+    <option name="ALTERNATIVE_JRE_PATH" value="1.8" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="true" />
+    <option name="MAIN_CLASS_NAME" value="me.lensfrex.vegetables.VegetablesMain" />
+    <module name="vegetables" />
+    <method v="2">
+      <option name="Make" enabled="true" />
+      <option name="com.soywiz.korge.intellij.UpdateResourceBeforeRunTask" enabled="false" />
+    </method>
+  </configuration>
+</component>

vegetables/src/me/lensfrex/vegetables/ResponseProcessor.java

@@ -0,0 +1,22 @@
+package me.lensfrex.vegetables;
+
+import me.lensfrex.vegetables.data.Vegetable;
+import me.lensfrex.vegetables.resopnse.UnityResponse;
+
+import java.util.ArrayList;
+
+/**
+ * 请求处理类，上层处理请求，主要为对返回数据的封装。
+ * 由于功能简单，仅有处理分页数据
+ */
+public class ResponseProcessor {
+    public UnityResponse<ArrayList<Vegetable>> getListPage(int pageNum, int pageSize) {
+        try {
+
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        return null;
+    }
+}

vegetables/src/me/lensfrex/vegetables/Tools.java

@@ -1,15 +1,95 @@
 package me.lensfrex.vegetables;
 
-import me.lensfrex.vegetables.data.Vegetables;
+import me.lensfrex.vegetables.data.Vegetable;
-import me.lensfrex.vegetables.utils.IOUtils;
+import me.lensfrex.vegetables.exceptions.IllegalPageParamException;
+import me.lensfrex.vegetables.exceptions.RequestPageTooLargeException;
 
-import java.util.ArrayList;
+import java.util.LinkedList;
 import java.util.List;
 
+/**
+ * 请求处理工具
+ * 由于功能较为简单，目前仅有获取分页数据的功能
+ */
 public class Tools {
-    public static final String SOURCE_FILE_PATH = "/vegetables.txt";
+    // 测试用路径，使用前记得改 :P
+    public static final String SOURCE_FILE_PATH = "C:\\Users\\lenfrex\\projects\\AmberGround\\vegetables\\resources\\vegetables.txt";
 
-//    public static List<Vegetables> getListPage(int pageNum, int pageSize) {
+    /**
-//        ArrayList<String> source = IOUtils.getListFromFile();
+     * 根据给定的页索引以及页大小，对全部蔬菜数据进行分页并返回分页后的List。
-//    }
+     *
+     * @param pageNum          页码（从1开始）
+     * @param pageSize         页大小
+     * @param allVegetableList 全体的待分页的蔬菜数据
+     * @return LinkedList<Vegetable> 分页后的蔬菜数据。
+     * @throws RequestPageTooLargeException 如果请求的页码已经超过了最大页数
+     * @throws IllegalPageParamException    如果分页请求的参数不对
+     */
+    public List<Vegetable> getListPage(int pageNum, int pageSize, List<Vegetable> allVegetableList)
+            throws RequestPageTooLargeException, IllegalPageParamException {
+
+        // 请求的分页大小或页码非法
+        if (pageNum <= 0 || pageSize <= 0) {
+            throw new IllegalPageParamException(
+                    String.format("分页请求的参数不对：pageNum: %d, pageSize: %d", pageNum, pageSize));
+        }
+
+        int resultSize = allVegetableList.size();
+
+        // 判断上一页的记录是不是已经超过最后一条记录，防止页码超过最大值
+        if ((pageNum - 1)*pageSize >= resultSize) {
+            throw new RequestPageTooLargeException();
+        }
+
+        LinkedList<Vegetable> pagedVegetableList = new LinkedList<>();
+        for (int i = (pageNum - 1)*pageSize; (i < pageNum*pageSize && i < resultSize); i++) {
+            pagedVegetableList.add(allVegetableList.get(i));
+        }
+
+        return pagedVegetableList;
+    }
+
+    /**
+     * 根据数据字符串解析并获取蔬菜数据
+     *
+     * @param vegetableStrings 蔬菜数据源字符串列表，字符串信息格式应为
+     *                         "蔬菜名 最低价 平均价 最高价 信息日期"
+     *                         其中信息日期格式应为 "yyyy-mm-dd hh:mm:ss"
+     * @return LinkedList<Vegetable> 解析后的蔬菜信息列表
+     */
+    public LinkedList<Vegetable> getAllVegetables(LinkedList<String> vegetableStrings) {
+        LinkedList<Vegetable> vegetables = new LinkedList<>();
+        for (String vegetableString : vegetableStrings) {
+            vegetables.add(parseVegetableInfo(vegetableString));
+        }
+
+        return vegetables;
+    }
+
+    private static void printMessage() {
+        System.out.println("Get data source from: " + SOURCE_FILE_PATH);
+        System.out.println("This is just for test.");
+        System.out.println("If some IO error occurred, try to change SOURCE_FILE_PATH in me.lensfrex.vegetables.Tools :P");
+    }
+
+    /**
+     * 解析Vegetable的信息字符串，并返回相应的蔬菜信息数据
+     *
+     * @param vegetableString 蔬菜信息字符串，
+     *                        格式应为 "蔬菜名 最低价 平均价 最高价 信息日期"
+     *                        其中信息日期格式应为 "yyyy-mm-dd hh:mm:ss"
+     * @return 蔬菜信息数据类
+     */
+    private Vegetable parseVegetableInfo(String vegetableString) {
+        String[] spilt = vegetableString.split(" ");
+        Vegetable vegetable = new Vegetable();
+
+        vegetable.setName(spilt[0]);
+        vegetable.setPrice(Double.parseDouble(spilt[1]), Vegetable.PRICE_MIN);
+        vegetable.setPrice(Double.parseDouble(spilt[2]), Vegetable.PRICE_AVG);
+        vegetable.setPrice(Double.parseDouble(spilt[3]), Vegetable.PRICE_MAX);
+        vegetable.setPriceDate(spilt[4] + spilt[5]);
+
+        return vegetable;
+    }
 }

vegetables/src/me/lensfrex/vegetables/VegetablesMain.java

@@ -1,9 +1,7 @@
 package me.lensfrex.vegetables;
 
 public class VegetablesMain {
-    public static final String SOURCE_FILE_PATH = "resources/vegetables.txt";
 
     public static void main(String[] args) {
-
     }
 }

vegetables/src/me/lensfrex/vegetables/data/Vegetable.java

@@ -0,0 +1,50 @@
+package me.lensfrex.vegetables.data;
+
+import java.util.Arrays;
+
+/**
+ * Vegetable的信息数据类，仅用于存储相关的数据结构
+ */
+public class Vegetable {
+    public static final int PRICE_MIN = 0;
+    public static final int PRICE_AVG = 1;
+    public static final int PRICE_MAX = 2;
+
+    private String name;
+    private double[] price;
+
+    private String priceDate;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public double getPrice(int priceType) {
+        return price[priceType];
+    }
+
+    public void setPrice(double price, int priceType) {
+        this.price[priceType] = price;
+    }
+
+    public String getPriceDate() {
+        return priceDate;
+    }
+
+    public void setPriceDate(String priceDate) {
+        this.priceDate = priceDate;
+    }
+
+    @Override
+    public String toString() {
+        return "Vegetable{" +
+                "name='" + name + '\'' +
+                ", price=" + Arrays.toString(price) +
+                ", priceDate='" + priceDate + '\'' +
+                '}';
+    }
+}

vegetables/src/me/lensfrex/vegetables/data/Vegetables.java

@@ -1,34 +0,0 @@
-package me.lensfrex.vegetables.data;
-
-import java.util.Date;
-
-public class Vegetables {
-    private String name;
-    private double[] price;
-
-    private String date;
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public double getPrice(int priceType) {
-        return price[priceType];
-    }
-
-    public void setPrice(double price, int priceType) {
-        this.price[priceType] = price;
-    }
-
-    public String getDate() {
-        return date;
-    }
-
-    public void setDate(String date) {
-        this.date = date;
-    }
-}

vegetables/src/me/lensfrex/vegetables/exceptions/IllegalPageParamException.java

@@ -0,0 +1,10 @@
+package me.lensfrex.vegetables.exceptions;
+
+/**
+ * 数据页请求数据非法异常
+ */
+public class IllegalPageParamException extends Exception{
+    public IllegalPageParamException(String message) {
+        super("IllegalPageRequest: " + message);
+    }
+}

vegetables/src/me/lensfrex/vegetables/exceptions/RequestPageTooLargeException.java

@@ -0,0 +1,10 @@
+package me.lensfrex.vegetables.exceptions;
+
+/**
+ * 用于当请求数据的页数已经超过最大页数时抛出的异常
+ */
+public class RequestPageTooLargeException extends Exception {
+    public RequestPageTooLargeException() {
+        super("请求结果的页数已超过最大数量");
+    }
+}

vegetables/src/me/lensfrex/vegetables/resopnse/ResponseTool.java

@@ -0,0 +1,24 @@
+package me.lensfrex.vegetables.resopnse;
+
+public class ResponseTool {
+    /**
+     * 构建请求成功的响应返回类
+     * @param data 请求到的数据
+     * @param message 请求信息
+     * @param <T> 请求的数据类型
+     * @return 构建出的请求响应类
+     */
+    public static <T> UnityResponse<T> success(T data, String message) {
+        return new UnityResponse<>(UnityResponse.ResultCode.SUCCESS, message, data);
+    }
+
+    /**
+     * 构建请求失败的响应返回类
+     * @param message 失败信息
+     * @param code 失败状态码，应从UnityResponse.ResultCode中定义的常量中选择
+     * @return 构建出的请求响应类
+     */
+    public static UnityResponse<String> error(String message, int code) {
+        return new UnityResponse<>(code, message, "null");
+    }
+}

vegetables/src/me/lensfrex/vegetables/resopnse/UnityResponse.java

@@ -0,0 +1,92 @@
+package me.lensfrex.vegetables.resopnse;
+
+/**
+ * 统一的返回数据结构，含有字段code, message, data
+ *
+ * @param <T> data的类型
+ */
+public class UnityResponse<T> {
+    /**
+     * 返回码。其值为ResultCode中定义的常量
+     */
+    private int code;
+    /**
+     * 返回的结果信息
+     */
+    private String message;
+    /**
+     * 请求的数据，其类型为声明返回类时指定的类型
+     */
+    private T data;
+
+    public UnityResponse(int code, String message, T data) {
+        this.code = code;
+        this.message = message;
+        this.data = data;
+    }
+
+    public UnityResponse() {
+        this.code = ResultCode.EMPTY_DATA;
+        this.message = "数据未初始化";
+        this.data = null;
+    }
+
+    public int getCode() {
+        return code;
+    }
+
+    public void setCode(int code) {
+        this.code = code;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+
+    public T getData() {
+        return data;
+    }
+
+    public void setData(T data) {
+        this.data = data;
+    }
+
+    @Override
+    public String toString() {
+        return "UnityResponse{" +
+                "code=" + code +
+                ", message='" + message + '\'' +
+                ", data=" + data +
+                '}';
+    }
+
+    /**
+     * 状态码的常量
+     */
+    static class ResultCode {
+        /**
+         * 请求成功
+         */
+        public static final int SUCCESS = 200;
+        /**
+         * 数据是空的
+         */
+        public static final int EMPTY_DATA = 0;
+        /**
+         * 请求的分页页码超过最大值
+         */
+        public static final int PAGE_OUT_OF_MAX = 100;
+        /**
+         * 请求的分页参数有误
+         */
+        public static final int PAGE_PARAM_WORN = 101;
+        /**
+         * 未知错误
+         */
+        public static final int UNKNOWN_ERROR = 503;
+    }
+}

vegetables/src/me/lensfrex/vegetables/utils/IOUtils.java

@@ -3,18 +3,18 @@ package me.lensfrex.vegetables.utils;
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.IOException;
-import java.util.ArrayList;
+import java.util.LinkedList;
 import java.util.List;
 
 public class IOUtils {
-    // copy 来自实例，偷懒了
     /**
-     * 读取文件，返回list集合
+     * 从文件中读取每行数据。
-     * @param path 文件的存储路径 D:\领航招新\培训计划\notes\vegetables.txt
+     * 为保证性能，此处使用LinkedList
-     * @return List<String> 集合
+     * @param path 文件的存储路径
+     * @return LinkedList<String> 读取到的每行文本
      */
-    public static List<String> getListFromFile(String path){
+    public static LinkedList<String> getListFromFile(String path) {
-        List<String> list = new ArrayList<>();
+        LinkedList<String> list = new LinkedList<>();
         try{
             //读取文件内容
             //创建一个新的 FileReader ，给定要读取的文件的名称。