标签:return name 对象 base obj Java null 接近 id
之前遇到一个需求需要做数据筛选上报以便控制峰值,我们想从集合中选取出变化最大的记录上传,集合的个数、集合类型、或者集合类元素的类型都不确定,于是在网上寻找相关的功能代码,奈何没找到,于是自己写了一个
定义相似度计算基本规则
- 已第一个参数p1为基准计算第二个参数p2与p1的相似度
- 基本数据类型中的数值类型统一使用父类Number类型进行计算
- 计算的结果为1表示完全相同,为0表示完全不同
- 不是同类型的对象为0
- 内存地址或者内容相同为1
- 数值计算方式fun(p1,p2):
- 第二个参数比第一个参数大:s=(p1 * 2)/(p1+p2) 计算结果0-1
- 第一个参数比第二个参数大:s=(p2 * 2)/(p1+p2) 计算结果0-1
- char类型转为number进行计算
- 字符型计算方式:
- 首先计算长度相似度为s1=fun(l1,l2)(数值计算方式)
- 在计算第二个字符串与第一个字符串相同个数c与第一个字符串的长度之间的相似度s2=fun(l1,c)
- 返回:s=s1*s2 计算结果0-1
- 布尔类型相等返回1,不相等返回0
- 非集合类对象分别计算两个对象(o1与o2)每个字段的相似度并求和sum除以字段的个数c:s=sum(fun(o1,o2))/c 计算结果0-1
- 两个参数都是集合时(第一个P[p1,p2...pn],第二个Q[q1,q2...qn]):
- 首先计算长度相似度为s1=fun(Pl,Ql)(数值计算方式)
- 在计算第二个集合与第一个集合相同个数c与第一个集合的长度之间的相似度s2=fun(Pl,c)
- 返回:s=s1*s2 计算结果0-1
从集合(只支持colection集合)中取合适对象
- 取最相似的元素:遍历集合参数P[p1,p2...pn],分别计算p1..pn与第二个参数p之间的相似度,取最大的一个相似度值对应的元素返回
- 取最不相似的元素:遍历集合参数P[p1,p2...pn],分别计算p1..pn与第二个参数p之间的相似度,取最小的一个相似度值对应的元素返回
代码:
最相似元素:
/** * 相似度最大计算 * * @return */ public static <T> T getMaxSimilarity(Collection<T> base, T t) { if (base == null || t == null || base.size() == 0) { return null; } T max = null; double maxSimilarity = 0; for (T obj : base) { double v = similarity(t, obj); System.out.println("maxSimilarity:" + v); if (maxSimilarity <= v || max == null) { max = obj; maxSimilarity = v; } } return max; }
取最不相似度元素:
/** * 相似度最小计算 * * @return */ public static <T> T getMinSimilarity(Collection<T> base, T t) { if (base == null || t == null || base.size() == 0) { return null; } T min = null; double minSimilarity = 0; for (T obj : base) { double v = similarity(t, obj); System.out.println("minSimilarity:" + v); if (minSimilarity >= v || min == null) { min = obj; minSimilarity = v; } } return min; }
相似度计算:
/** * 相似度计算 * * @return */ public static double similarity(Object base, Object obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } if (!base.getClass().equals(obj.getClass())) { return 0; } if (base instanceof Boolean) { return booleanSimilarity((Boolean) base, ((Boolean) obj)); } if (base instanceof Character) { return numberSimilarity((int) base, (int) obj); } if (base instanceof Number) { return numberSimilarity((Number) base, (Number) obj); } if (base instanceof CharSequence) { return stringSimilarity(base.toString(), obj.toString()); } if (base instanceof Collection) { return collectionSimilarity((Collection) base, (Collection) obj); } if (base instanceof Map) { return mapSimilarity((Map) base, (Map) obj); } if (base.getClass().isArray()) { return arraySimilarity(base, obj); } return objectSimilarity(base, obj); }
查看所有代码:
//package me.muphy.util; import java.lang.reflect.Array; import java.lang.reflect.Field; import java.util.Collection; import java.util.Map; /** * 对象相似度算法 * getMaxSimilarity 重集合中获取最接近的两个对象 * getMinSimilarity 重集合中获取最不接近的两个对象 * similarity 比较两个对象的相似度 */ public class SimilarityAlgorithmUtils { /** * 相似度最大计算 * * @return */ public static <T> T getMaxSimilarity(Collection<T> base, T t) { if (base == null || t == null || base.size() == 0) { return null; } T max = null; double maxSimilarity = 0; for (T obj : base) { double v = similarity(t, obj); System.out.println("maxSimilarity:" + v); if (maxSimilarity <= v || max == null) { max = obj; maxSimilarity = v; } } return max; } /** * 相似度最小计算 * * @return */ public static <T> T getMinSimilarity(Collection<T> base, T t) { if (base == null || t == null || base.size() == 0) { return null; } T min = null; double minSimilarity = 0; for (T obj : base) { double v = similarity(t, obj); System.out.println("minSimilarity:" + v); if (minSimilarity >= v || min == null) { min = obj; minSimilarity = v; } } return min; } /** * 相似度计算 * * @return */ public static double similarity(Object base, Object obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } if (!base.getClass().equals(obj.getClass())) { return 0; } if (base instanceof Boolean) { return booleanSimilarity((Boolean) base, ((Boolean) obj)); } if (base instanceof Character) { return numberSimilarity((int) base, (int) obj); } if (base instanceof Number) { return numberSimilarity((Number) base, (Number) obj); } if (base instanceof CharSequence) { return stringSimilarity(base.toString(), obj.toString()); } if (base instanceof Collection) { return collectionSimilarity((Collection) base, (Collection) obj); } if (base instanceof Map) { return mapSimilarity((Map) base, (Map) obj); } if (base.getClass().isArray()) { return arraySimilarity(base, obj); } return objectSimilarity(base, obj); } /** * 数值相似度 * * @param base * @param obj * @return */ private static double arraySimilarity(Object base, Object obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } int baseLength = Array.getLength(base); int objLength = Array.getLength(obj); double k = 0; for (int i = 0; i < baseLength; i++) { for (int j = 0; j < objLength; j++) { k += objectSimilarity(Array.get(base, i), Array.get(obj, j)); //取出数组中每个值 } } return numberSimilarity(baseLength, objLength) * numberSimilarity(baseLength, k); } /** * 数值相似度 * * @param base * @param obj * @return */ private static double mapSimilarity(Map base, Map obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } double k = 0; for (Object key : base.keySet()) { if (obj.containsKey(key)) { k += objectSimilarity(base.get(key), obj.get(key)); } } return numberSimilarity(base.size(), obj.size()) * numberSimilarity(base.size(), k); } /** * 数值相似度 * * @param base * @param obj * @return */ private static double collectionSimilarity(Collection base, Collection obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } int k = 0; for (Object o1 : base) { for (Object o2 : obj) { k += objectSimilarity(o1, o2); } } return numberSimilarity(base.size(), obj.size()) * numberSimilarity(base.size(), k); } /** * 数值相似度 * * @param base * @param obj * @return */ private static double objectSimilarity(Object base, Object obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } if (base.equals(obj)) { return 1; } Field[] fields = base.getClass().getFields(); double sum = 0, k = 0; for (Field field : fields) { Object o1 = null, o2 = null; try { o1 = field.get(base); o2 = field.get(obj); } catch (IllegalAccessException e) { e.printStackTrace(); } k++; sum += similarity(o1, o2); } if (k == 0) { return 0; } return sum / k; } /** * 数值相似度 * * @param base * @param obj * @return */ private static double booleanSimilarity(Boolean base, Boolean obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } return base.booleanValue() == obj.booleanValue() ? 1 : 0; } /** * 数值相似度 * * @param base * @param obj * @return */ private static double charSimilarity(Character base, Character obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } return numberSimilarity((int) base.charValue(), (int) obj.charValue()); } /** * 数值相似度 * * @param base * @param obj * @return */ private static double numberSimilarity(Number base, Number obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } double b = base.doubleValue(); double o = obj.doubleValue(); double sum = b + o; if (sum < 0.00001) { if (b < 0.00001) { return 1; } } if (o >= b) { return b * 2 / sum; } return o * 2 / sum; } /** * 字符串相似度 * * @param base * @param obj * @return */ private static double stringSimilarity(String base, String obj) { if (base == obj) { return 1; } if (base == null || obj == null) { return 0; } int k = 0; for (int i = 0; i < base.length(); i++) { for (int j = 0; j < obj.length(); j++) { if (base.charAt(i) == obj.charAt(j)) { k++; } } } if (base.length() != obj.length()) { return numberSimilarity(base.length(), obj.length()) * numberSimilarity(base.length(), k); } return numberSimilarity(base.length(), k); } }View Code
测试
查看测试代码:
//package me.muphy.temp; import com.alibaba.fastjson.JSON; import com.moefon.scenemonitor.util.SimilarityAlgorithmUtils; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Objects; public class Test { public Test() { } public static void main(String[] args) { Test.arrayTest(); Test.listTest(); Test.mapTest(); Test.intSimilarityTest(); Test.objectSimilarityTest(); } public static void intSimilarityTest() { List<Integer> ints1 = new ArrayList<Integer>() {{ add(7); add(8); add(10); add(12); }}; int i = 9; Integer minSimilarity = SimilarityAlgorithmUtils.getMinSimilarity(ints1, i); System.out.println("list:" + JSON.toJSONString(ints1) + "与" + i + "之间的最不接近的是:" + minSimilarity); Integer maxSimilarity = SimilarityAlgorithmUtils.getMaxSimilarity(ints1, i); System.out.println("list:" + JSON.toJSONString(ints1) + "与" + i + "之间的最接近的是:" + maxSimilarity); } public static void objectSimilarityTest() { List<A> ints1 = new ArrayList<A>() {{ add(new A("oyerwhflkf,dasf")); add(new A("hjkloipsggsdfd")); add(new A("ppiffalshfklhf")); add(new A("asdfasljlsadhkn")); }}; A a = new A("pfasfklh"); A minSimilarity = SimilarityAlgorithmUtils.getMinSimilarity(ints1, a); System.out.println("list:" + JSON.toJSONString(ints1) + "与" + a.toString() + "之间的最不接近的是:" + minSimilarity); A maxSimilarity = SimilarityAlgorithmUtils.getMaxSimilarity(ints1, a); System.out.println("list:" + JSON.toJSONString(ints1) + "与" + a.toString() + "之间的最接近的是:" + maxSimilarity); } public static void arrayTest() { int[] ints1 = {5, 6, 7, 8}; int[] ints2 = {7, 8, 9, 1}; double similarity = SimilarityAlgorithmUtils.similarity(ints1, ints2); System.out.println("数组:" + JSON.toJSONString(ints1) + "与" + JSON.toJSONString(ints2) + "之间的相似度:" + similarity); } public static void mapTest() { Map<String, A> map1 = new HashMap<>(); Map<String, A> map2 = new HashMap<>(); A a1 = new A("a1"); A a2 = new A("a2"); A a3 = new A("a3"); A a4 = new A("a4"); A a5 = new A("a5"); A a6 = new A("a6"); A a7 = new A("a7"); map1.put("a1", a1); map1.put("a2", a2); map1.put("a3", a3); map2.put("a3", a3); map1.put("a4", a4); map2.put("a4", a4); map1.put("a5", a5); map2.put("a5", a5); map2.put("a6", a6); map1.put("a6", a6); map2.put("a7", a7); double similarity = SimilarityAlgorithmUtils.similarity(map1, map2); System.out.println("map:" + JSON.toJSONString(map1) + "与" + JSON.toJSONString(map2) + "之间的相似度:" + similarity); } public static void listTest() { List<A> list1 = new ArrayList<>(); List<A> list2 = new ArrayList<>(); A a1 = new A("a1"); A a2 = new A("a2"); A a3 = new A("a3"); list1.add(a1); list1.add(a2); list1.add(a3); list1.add(new A("a4")); list1.add(new A("a3")); list2.add(new A("a3")); list2.add(a2); list2.add(new A("a4")); list2.add(new A("a5")); double similarity = SimilarityAlgorithmUtils.similarity(list1, list2); System.out.println("list:" + JSON.toJSONString(list1) + "与" + JSON.toJSONString(list2) + "之间的相似度:" + similarity); } static class A { public String name; public int id = 5; public A(String name) { this.name = name; } @Override public String toString() { return "A{" + "name='" + name + '\'' + ", id=" + id + '}'; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; A a = (A) o; return Objects.equals(id, a.id) && Objects.equals(name, a.name); } @Override public int hashCode() { return Objects.hash(name) * id; } } }View Code
测试结果:
I/System.out: 数组:[5,6,7,8]与[7,8,9,1]之间的相似度:0.4
I/System.out: list:[{"id":5,"name":"a1"},{"id":5,"name":"a2"},{"id":5,"name":"a3"},{"id":5,"name":"a4"},{"id":5,"name":"a3"}]与[{"id":5,"name":"a3"},{"id":5,"name":"a2"},{"id":5,"name":"a4"},{"id":5,"name":"a5"}]之间的相似度:0.7901234567901234
I/System.out: map:{"a1":{"id":5,"name":"a1"},"a2":{"id":5,"name":"a2"},"a3":{"id":5,"name":"a3"},"a4":{"id":5,"name":"a4"},"a5":{"id":5,"name":"a5"},"a6":{"id":5,"name":"a6"}}与{"a3":{"id":5,"name":"a3"},"a4":{"id":5,"name":"a4"},"a5":{"id":5,"name":"a5"},"a6":{"id":5,"name":"a6"},"a7":{"id":5,"name":"a7"}}之间的相似度:0.7272727272727273
list:[7,8,10,12]与9之间的最不接近的是:12
list:[7,8,10,12]与9之间的最接近的是:10
I/System.out: list:[{"id":5,"name":"oyerwhflkf,dasf"},{"id":5,"name":"hjkloipsggsdfd"},{"id":5,"name":"ppiffalshfklhf"},{"id":5,"name":"asdfasljlsadhkn"}]与A{name='pfasfklh', id=5}之间的最不接近的是:A{name='ppiffalshfklhf', id=5}
I/System.out: list:[{"id":5,"name":"oyerwhflkf,dasf"},{"id":5,"name":"hjkloipsggsdfd"},{"id":5,"name":"ppiffalshfklhf"},{"id":5,"name":"asdfasljlsadhkn"}]与A{name='pfasfklh', id=5}之间的最接近的是:A{name='hjkloipsggsdfd', id=5}
就这样吧,我可能自己都不知道在写啥~~
标签:return,name,对象,base,obj,Java,null,接近,id 来源: https://www.cnblogs.com/muphy/p/14254619.html
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