本文共 12766 字，大约阅读时间需要 42 分钟。
最近接触的一个项目中，其中有一个功能需求就是号码归属地的查询，乍一看确实挺简单，反正数据库也都有了，只不过就是查询一下而已嘛！到了实际程序设计的时候才发现，5M的数据库光要加载起来就得1分多钟，放在android手机上跑的太慢了，没办法，只好另辟蹊径了！！！
本文的基本思路如下：
1. 先把数据进行分组，即每一个地区一个组，例如
1898742 1898743 1898744 :云南曲靖
1894380 1894381 1894382 :吉林松原
2. 把电话号码进行排序，目的就是为了找到电话号码的区间，例如
1894815 --> 1899819 :广东珠海，
找到了一个区段，这样就不用把每个电话号码读存储下来， 只要存储一个区间就好，
这样可以大大节省存储空间
3. 设计新的存储格式，本文的程序采用如下方式存储
| 第一条电话记录在文件中的位置偏移 | 最后一条电话记录在文件中的位置偏移 |
| 电话归属地的字符串（例如：辽宁大连，湖北武汉，广东珠海，广东深圳..., 字符串之间以逗号分隔） | |
| 第一条电话记录 （例如：1894815{代表号码段起始值} 5{代表连续的号码个数} 2{代表该归属地字符串在所有归属地字符串中的偏移量}） | |
| 第二条电话记录 | |
| ... | |
| 最后一条电话记录 | |
4. 归属地查询
根据用户输入的电话号码，利用二分查找法可快速定位到该记录在文件中的位置偏移，读出该记录中位置字符串的偏移值，进而查表即可找到归属地
程序设计，源码如下：
package com.carey.tel;import java.io.BufferedReader;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.RandomAccessFile;import java.util.ArrayList;import java.util.Collections;import java.util.Date;import java.util.HashMap;public class JavaTelArea { private static JavaTelArea jta = null; private static final String INDEXDATAFILE = "tel.bin"; private static Hearder cacheHearder = null; private static AreaCode cacheAreaCode = null; private static String cacheIndexFilePath = null; public static void main(String[] args) { JavaTelArea ctc = JavaTelArea.getInstance(); //ctc.genIndexFile("e:\", "e:\telphone.txt"); String indexPath = "e:\"; long startTime = new Date().getTime(); String searchNum = "13889650920"; String res = ctc.searchTel(indexPath, searchNum); System.out.println(searchNum + " : " + res); System.out.println(System.currentTimeMillis() - startTime + "ms"); startTime = new Date().getTime(); searchNum = "+8613659867583"; res = ctc.searchTel(indexPath, searchNum); System.out.println(searchNum + " : " + res); System.out.println(System.currentTimeMillis() - startTime + "ms"); startTime = new Date().getTime(); searchNum = "1301815"; res = ctc.searchTel(indexPath, searchNum); System.out.println(searchNum + " : " + res); System.out.println(System.currentTimeMillis() - startTime + "ms"); startTime = new Date().getTime(); searchNum = "1301816"; res = ctc.searchTel(indexPath, searchNum); System.out.println("没有预测"); System.out.println(searchNum + " : " + res); System.out.println(System.currentTimeMillis() - startTime + "ms"); startTime = new Date().getTime(); searchNum = "1301816"; res = ctc.searchTel(indexPath, searchNum, true); System.out.println("根据号码连贯性原理预测"); System.out.println(searchNum + " : " + res); System.out.println(System.currentTimeMillis() - startTime + "ms"); startTime = new Date().getTime(); searchNum = "1301817"; res = ctc.searchTel(indexPath, searchNum); System.out.println(searchNum + " : " + res); System.out.println(System.currentTimeMillis() - startTime + "ms"); } private HashMap generateTestData() { HashMap telToAreaCode = new HashMap (); telToAreaCode.put(1310944l, "新疆伊犁州"); telToAreaCode.put(1301263l, "新疆伊犁州"); telToAreaCode.put(1301264l, "新疆伊犁州"); telToAreaCode.put(1301260l, "新疆伊犁州"); telToAreaCode.put(955L, "海南"); telToAreaCode.put(1320955l, "海南"); telToAreaCode.put(1320957l, "海南"); telToAreaCode.put(1300561L, "陕西商州"); telToAreaCode.put(1300562L, "陕西商州"); return telToAreaCode; } public static synchronized JavaTelArea getInstance() { if (jta == null) { jta = new JavaTelArea(); } return jta; } /** * Generate Index File (tel.bin) * */ private void genIndexFile(String indexFilePath, String souceFile) { ArrayList strs = readFileToList(souceFile); HashMap telToArea = createTel2AreaHashMap(strs); writeDate(indexFilePath + INDEXDATAFILE, telToArea); } /** * read file content to String array list, every line one string. * */ private ArrayList readFileToList(String filePath) { final ArrayList strLists = new ArrayList (); BufferedReader bReader = null; try { bReader = new BufferedReader(new InputStreamReader(new FileInputStream(filePath))); String str = bReader.readLine(); while (str != null) { strLists.add(str); str = bReader.readLine(); } } catch (Exception e) { e.printStackTrace(); } finally { if (bReader != null) { try { bReader.close(); } catch (IOException e) { e.printStackTrace(); } } } return strLists; } /** * create telephone number to area hash map. * */ HashMap createTel2AreaHashMap(ArrayList strs) { final HashMap telToArea = new HashMap (); String[] tels = null; int len = 0; String strArea = null; for (String string : strs) { tels = string.split(" "); len = tels.length; strArea = tels[len - 1].substring(1); for (int i = 0; i < len - 1; i++) { telToArea.put(Long.valueOf(tels[i]), strArea); } } return telToArea; } /** * combined the adjacent Records. * */ private void combinedRecords(ArrayList records, Record newRecord) { int size = records.size(); if (size > 0&& records.get(size - 1).areacodeIndex == newRecord.areacodeIndex) { // combined Record lastRecord = records.get(size - 1); lastRecord.numCnt = (int) (newRecord.baseTelNum - lastRecord.baseTelNum) + newRecord.numCnt; } else { records.add(newRecord); } } /** * write index info to file. * */ private void writeDate(String filePath, HashMap telToAreaCode) { // 1. get all area info ArrayList tmpAreaCodes = new ArrayList (telToAreaCode.values()); ArrayList strAreaCodes = new ArrayList (); for (String str : tmpAreaCodes) { if (!strAreaCodes.contains(str)) { strAreaCodes.add(str); } } tmpAreaCodes.clear(); tmpAreaCodes = null; StringBuffer sb = new StringBuffer(); for (String str : strAreaCodes) { sb.append(str + ","); } sb.deleteCharAt(sb.length() - 1); AreaCode areaCode = new AreaCode(sb.toString()); areaCode.print(); // 2. Sort HashMap and combined the adjacent telephone number ArrayList telNunms = new ArrayList (telToAreaCode.keySet()); Collections.sort(telNunms); ArrayList records = new ArrayList (); long baseNum = 0; String baseArea = null; int numCnt = 0; for (Long tm : telNunms) { if (numCnt == 0) { baseNum = tm; baseArea = telToAreaCode.get(tm); numCnt = 1; } else { if (tm == baseNum + numCnt && baseArea.equals(telToAreaCode.get(tm))) { numCnt++; } else { combinedRecords(records, new Record(baseNum, numCnt, strAreaCodes.indexOf(baseArea))); baseNum = tm; baseArea = telToAreaCode.get(tm); numCnt = 1; } } } combinedRecords(records, new Record(baseNum, numCnt, strAreaCodes.indexOf(baseArea))); // for (Record record : records) { // record.print(); // } // 3. Write data to the file RandomAccessFile raf = null; try { raf = new RandomAccessFile(filePath, "rw"); raf.seek(0); Hearder hearder = new Hearder(); hearder.firstRecordOffset = hearder.Size() + areaCode.Size(); hearder.lastRecordOffset = hearder.firstRecordOffset + (records.size() - 1) * records.get(0).Size(); hearder.print(); hearder.write(raf); areaCode.write(raf); for (Record record : records) { record.write(raf); } } catch (Exception e) { e.printStackTrace(); } finally { if (raf != null) { try { raf.close(); } catch (IOException e) { e.printStackTrace(); } } } } class Hearder { int firstRecordOffset; int lastRecordOffset; public int Size() { return (Integer.SIZE + Integer.SIZE) / Byte.SIZE; } public void write(RandomAccessFile raf) throws IOException { raf.writeInt(this.firstRecordOffset); raf.writeInt(this.lastRecordOffset); } public void read(RandomAccessFile raf) throws IOException { this.firstRecordOffset = raf.readInt(); this.lastRecordOffset = raf.readInt(); } public void print() { System.out.println("===== Hearder ===== "); System.out.println("[" + firstRecordOffset + " , " + lastRecordOffset + "]"); } } class AreaCode { private String areacode; private String[] codes; public AreaCode() { this(""); } public AreaCode(String areacode) { this.areacode = areacode; this.codes = null; } public int Size() { return areacode.getBytes().length + (Integer.SIZE / Byte.SIZE); } public void print() { System.out.println("===== AreaCode ===== "); System.out.println("[" + areacode.getBytes().length + "]" + areacode); } public void write(RandomAccessFile raf) throws IOException { raf.writeInt(areacode.getBytes().length); raf.write(this.areacode.getBytes()); } public void read(RandomAccessFile raf) throws IOException { byte[] bytes = new byte[raf.readInt()]; raf.read(bytes); this.areacode = new String(bytes); } public String getCodeByIndex(int index) { if (this.codes == null) { this.codes = this.areacode.split(","); } return (index < 0 || this.codes == null || index >= this.codes.length) ? null : this.codes[index]; }}class Record { long baseTelNum; int numCnt; int areacodeIndex; public Record() { this(0, 0, 0); } public Record(long baseTelNum, int numCnt, int areacodeIndex) { this.baseTelNum = baseTelNum; this.numCnt = numCnt; this.areacodeIndex = areacodeIndex; } public void print() { System.out.println("===== Record ===== "); System.out.println("<" + baseTelNum + "> <" + numCnt + "> <" + areacodeIndex + ">"); } public int Size() { return (Long.SIZE + Integer.SIZE) / Byte.SIZE; } public void write(RandomAccessFile raf) throws IOException { raf.writeLong(this.baseTelNum); int tmp = this.numCnt << 16; tmp += 0xFFFF & this.areacodeIndex; raf.writeInt(tmp); } public void read(RandomAccessFile raf) throws IOException { this.baseTelNum = raf.readLong(); int tmp = raf.readInt(); this.numCnt = tmp >> 16; this.areacodeIndex = 0xFFFF & tmp; } public int inWhich(long telNum) { if (telNum < this.baseTelNum) { return -1; } else if (telNum >= this.baseTelNum + this.numCnt) { return 1; } else { return 0; } } } public String searchTel(String indexFilePath, String telNum) { return searchTel(indexFilePath, telNum, false); } /** * search * */ public String searchTel(String indexFilePath, String telNum, boolean forecast) { StringBuffer sb = new StringBuffer(telNum); // + if (sb.charAt(0) == '+') { sb.deleteCharAt(0); } // 86 if (sb.charAt(0) == '8' && sb.charAt(1) == '6') { sb.delete(0, 2); } // 以0开头，是区号 if (sb.charAt(0) == '0') { sb.deleteCharAt(0); // 首先按照4位区号查询，若查询为空，再按3位区号查询 if (sb.length() >= 3) { sb.delete(3, sb.length()); } String dial = searchTel(indexFilePath, Long.valueOf(sb.toString()),false); if (dial != null) { return dial; } if (sb.length() >= 2) { sb.delete(2, sb.length()); } } // 以1开头，是手机号或者服务行业号码 else if (sb.charAt(0) == '1') { // 首先按照手机号码查询，若查询为空，再按特殊号码查询 if (sb.length() > 7) { String dial = searchTel(indexFilePath, Long.valueOf(sb.substring(0, 8)),false); if (dial != null) { return dial; } dial = searchTel(indexFilePath, Long.valueOf(sb.toString()),false); if (dial != null) { return dial; } // 只需要保留7位号码就ok了，多余的删掉 if (sb.length() > 7) { sb.delete(7, sb.length()); } } else { //小于7位，最有可能是服务号码 //do nothing. } } // 以其他数字开头，这也不知道是啥号码了 else { //do nothing. } return searchTel(indexFilePath, Long.valueOf(sb.toString()), forecast); } private String searchTel(String indexFilePath, long telNum, boolean forecast) { RandomAccessFile raf = null; try { raf = new RandomAccessFile(indexFilePath + INDEXDATAFILE, "r"); if (cacheIndexFilePath == null || !cacheIndexFilePath.equals(indexFilePath)) { cacheIndexFilePath = indexFilePath; cacheHearder = new Hearder(); cacheHearder.read(raf); cacheHearder.print(); cacheAreaCode = new AreaCode(); cacheAreaCode.read(raf); cacheAreaCode.print(); } int index = lookUP(raf, cacheHearder.firstRecordOffset, cacheHearder.lastRecordOffset, telNum, forecast); return cacheAreaCode.getCodeByIndex(index); } catch (Exception e) { e.printStackTrace(); } finally { if (raf != null) { try { raf.close(); } catch (IOException e) { e.printStackTrace(); } } } return null; } private int lookUP(RandomAccessFile raf, long startpos, long endpos, long looknum, boolean forecast) throws IOException { Record record = new Record(); long seekpos = 0; do { seekpos = startpos + (endpos - startpos) / record.Size() / 2 * record.Size(); raf.seek(seekpos); record.read(raf); if (record.inWhich(looknum) > 0) { startpos = seekpos + record.Size(); } else if (record.inWhich(looknum) < 0) { endpos = seekpos - record.Size(); } else { return record.areacodeIndex; } } while (startpos <= endpos); if (forecast) { return record.areacodeIndex; } else { return -1; } }} 程序运行情况如下：
==== Hearder =====[4554 , 605622]===== AreaCode ===== [4542]北福建南平,福建三明,海果洛,青海海南,...13889650920 : 辽宁大连20ms+8613659867583 : 湖北武汉2ms1301815 : 四川泸州2ms没有预测1301816 : null2ms根据号码连贯性原理预测1301816 : 四川泸州1ms1301817 : 四川宜宾2ms
可以看到，除了第一次查询的时候要加载索引文件大约耗时20ms，以后的查询基本都在1ms，速度非常快了！！！
本程序的测试data文件下载
转载地址：http://nolli.baihongyu.com/