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 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中國", "國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
     
       AlgorithmMap = new HashMap
      
       ();                        //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
       
         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;    }}