由于工作需要,公司数据要与客户的数据进度匹配,在网上找了一些方法感觉还不错,我采用的是余弦算法。这是我的参考地址http://www.maoguangpu.com/post/117.html。 里面只做对中文的处理,我做了些改进,中,英,符号都可进行。上代码
import java.io.UnsupportedEncodingException; import java.util.HashMap; import java.util.Iterator; import java.util.Map; public class StringSimilar { public static void main (String [] args){ System.out.println(StringSimilar.getSimilarity("a中国", "国a")); } public static double getSimilarity(String doc1, String doc2) { doc1=doc1.trim(); doc2=doc2.trim(); if (doc1 != null && doc1.length() > 0 && doc2 != null && doc2.length() > 0) { Map<Integer, int[]> AlgorithmMap = new HashMap<Integer, int[]>(); //将两个字符串中的中文字符以及出现的总数封装到,AlgorithmMap中 for (int i = 0; i < doc1.length(); i++) { char d1 = doc1.charAt(i); if(isHanZi(d1)){ int charIndex = getGB2312Id(d1); if(charIndex != -1){ int[] fq = AlgorithmMap.get(charIndex); if(fq != null && fq.length == 2){ fq[0]++; }else { fq = new int[2]; fq[0] = 1; fq[1] = 0; AlgorithmMap.put(charIndex, fq); } } }else{ int by=(int)-String.valueOf(d1).getBytes()[0]; int[] fq = AlgorithmMap.get(by); if(fq != null && fq.length == 2){ fq[0]++; }else { fq = new int[2]; fq[0] = 1; fq[1] = 0; AlgorithmMap.put(by, fq); } } } for (int i = 0; i < doc2.length(); i++) { char d2 = doc2.charAt(i); if(isHanZi(d2)){ int charIndex = getGB2312Id(d2); if(charIndex != -1){ int[] fq = AlgorithmMap.get(charIndex); if(fq != null && fq.length == 2){ fq[1]++; }else { fq = new int[2]; fq[0] = 0; fq[1] = 1; AlgorithmMap.put(charIndex, fq); } } }else{ int by=(int)-String.valueOf(d2).getBytes()[0]; int[] fq = AlgorithmMap.get(by); if(fq != null && fq.length == 2){ fq[1]++; }else { fq = new int[2]; fq[0] = 0; fq[1] = 1; AlgorithmMap.put(by, fq); } } } Iterator<Integer> iterator = AlgorithmMap.keySet().iterator(); double sqdoc1 = 0; double sqdoc2 = 0; double denominator = 0; while(iterator.hasNext()){ int[] c = AlgorithmMap.get(iterator.next()); denominator += c[0]*c[1]; sqdoc1 += c[0]*c[0]; sqdoc2 += c[1]*c[1]; } return denominator / Math.sqrt(sqdoc1*sqdoc2); } else { throw new NullPointerException( " the Document is null or have not cahrs!!"); } } public static boolean isHanZi(char ch) { // 判断是否汉字 return (ch >= 0x4E00 && ch <= 0x9FA5); } /** * 根据输入的Unicode字符,获取它的GB2312编码或者ascii编码, * * @param ch * 输入的GB2312中文字符或者ASCII字符(128个) * @return ch在GB2312中的位置,-1表示该字符不认识 */ public static short getGB2312Id(char ch) { try { byte[] buffer = Character.toString(ch).getBytes("GB2312"); if (buffer.length != 2) { // 正常情况下buffer应该是两个字节,否则说明ch不属于GB2312编码,故返回'?',此时说明不认识该字符 return -1; } int b0 = (int) (buffer[0] & 0x0FF) - 161; // 编码从A1开始,因此减去0xA1=161 int b1 = (int) (buffer[1] & 0x0FF) - 161; // 第一个字符和最后一个字符没有汉字,因此每个区只收16*6-2=94个汉字 return (short) (b0 * 94 + b1); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return -1; } }