记录英语单词时，想把英语和中文翻译分别对齐，有些人写代码喜欢把变量按这种方式对齐。在网上没搜到相关方法，于是自己试着写代码去实现，原本以为很简单，写的时候才发现有不少问题。先看效果：

普通的

对齐前：

对齐后：

发挥点创意

对齐前：

对齐后：

实现

实现的思路比较简单，读取文本文件，按正则分割，找出最长的部分，补齐空格，输出。

看起来相当简单，花了一个多小时，就写出来了，马上运行，发现输出一团糟，去查看每个部分的字符数，个数是一样的，网上一搜，原来跟字体有关系，好吧，那换个等宽的字体。换好字体后有些地方已经对齐了，有些地方还是没对齐，发现是中文的问题，中文宽度与英文宽度不相同，于是首先根据正则去判断字符是中文还是英文，然后自己实现计算字符长度的方法，在判断中文字符上折腾了许久，因为标点符号等等都要考虑进去，反正是来来回回试了好久，对Unicode编码范围不熟悉，没办法。终于，好像都搞定了，反复测试，突然发现第一行的对齐少了一个空格，尼玛，这是怎么回事啊，Debug发现第一行的最开始有一个奇怪的字符"\uFEFF"，这他妈是什么鬼，上网搜，发现是Unicode编码的什么BOM头，好吧，不管它是什么鬼，直接把它去掉了……

反正是遇到了各种各样的问题，与字符集相关的问题实在是太头疼了。另外，我没有去处理编码的问题，所以文本的编码需要和IDE的编码保持一致，否则就会产生乱码。

源码

看过《重构》和《代码整洁之道》之后，写代码时时刻想着要写干净点，扩展性强点，经过反复修改，最终自己觉得还行吧，当然，肯定有不少值得改进的地方，现在就这样吧。

App.java

1 packagetextalign;2

3 importjava.io.IOException;4

5 /**

6 *@authortingl7 *@version2017/9/278 */

9 public classApp {10

11 public static voidmain(String[] args) {12 long start =System.currentTimeMillis();13

14 String filePath = "C:\\Users\\tingl\\Desktop\\Test2.txt";15 TextAlign textAlign = new TextAlign(/*"，|。|,|[.]|( {2,})|\t|　+"*/);16

17 if (args.length > 0) {18 filePath = args[0];19 }20 try{21 textAlign.align(filePath);22 } catch(IOException e) {23 e.printStackTrace();24 }25

26 System.out.println(System.currentTimeMillis() -start);27 }28 }

TextAlign.java

1 packagetextalign;2

3 importjava.io.IOException;4 importjava.util.List;5 importjava.util.regex.Pattern;6

7 /**

8 *@authortingl9 *@version2017/9/2710 */

11 public classTextAlign {12 private static final String CHINESE_CHARACTER = "[\u4e00-\u9fa5]|[\uFE30-\uFFA0]|[\u3000-\u303F]";13 private static final Pattern CHINESE_CHARACTER_PATTERN =Pattern.compile(CHINESE_CHARACTER);14 private static final int SEPARATE_SPACE_AMOUNT = 4;15

16 privateTextAlignFileUtil textAlignFileUtil;17 private ListtextLines;18 private int[] longestBlockLengths;19

20 publicTextAlign() {21 textAlignFileUtil = newTextAlignFileUtil();22 }23

24 publicTextAlign(String spiltRegex) {25 textAlignFileUtil = newTextAlignFileUtil(spiltRegex);26 }27

28 public void align(String filePath) throwsIOException {29 textLines =textAlignFileUtil.readToList(filePath);30 initLongestBlockLengths();31 fillTextLinesBySpaces();32 textAlignFileUtil.write();33 }34

35 private voidinitLongestBlockLengths() {36 int longestArrayLength = 0;37 for(String[] blocks : textLines) {38 if (blocks.length >longestArrayLength) {39 longestArrayLength =blocks.length;40 }41 }42 longestBlockLengths = new int[longestArrayLength];43 fillLongestBlockLengths();44 }45

46 private voidfillLongestBlockLengths() {47 for(String[] blocks : textLines) {48 if (blocks.length < 2) continue;49 for (int i = 0; i < blocks.length; i++) {50 int length =stringLengthFitWidth(blocks[i]);51 if (length >longestBlockLengths[i]) {52 longestBlockLengths[i] =length;53 }54 }55 }56 }57

58 private intstringLengthFitWidth(String s) {59 if (!CHINESE_CHARACTER_PATTERN.matcher(s).find()) {60 returns.length();61 }62 int length = 0;63 for (String c : s.split("")) {64 if(CHINESE_CHARACTER_PATTERN.matcher(c).find()) {65 length++;66 }67 length++;68 }69 returnlength;70 }71

72 private voidfillTextLinesBySpaces() {73 for(String[] blocks : textLines) {74 for (int i = 0; i < blocks.length - 1; i++) {75 String block =blocks[i];76 int spaceAmount = longestBlockLengths[i] - stringLengthFitWidth(block) +SEPARATE_SPACE_AMOUNT;77 blocks[i] = block +spaces(spaceAmount);78 }79 }80 }81

82 private String spaces(intspaceAmount) {83 StringBuilder spaces = newStringBuilder();84 for (int i = 0; i < spaceAmount; i++) {85 spaces.append(" ");86 }87 returnspaces.toString();88 }89 }

TextAlignFileUtil.java

1 packagetextalign;2

3 import java.io.*;4 importjava.util.ArrayList;5 importjava.util.Arrays;6 importjava.util.List;7

8 /**

9 *@authortingl10 *@version2017/9/2711 */

12 classTextAlignFileUtil {13 private static final String FILENAME_POSTFIX = "_aligned";14 private String spiltRegex = "( {2,})|\t";15 private ListtextLines;16 privateString outPath;17

18 TextAlignFileUtil() {19 }20

21 TextAlignFileUtil(String spiltRegex) {22 this.spiltRegex =spiltRegex;23 }24

25 List readToList(String path) throwsIOException {26 File file = newFile(path);27 returnreadToList(file);28 }29

30 private List readToList(File file) throwsIOException {31 getOutPath(file.getAbsolutePath());32 try (BufferedReader reader = new BufferedReader(newFileReader(file))) {33 textLines = new ArrayList<>();34 String line;35 while ((line = reader.readLine()) != null) {36 textLines.add(removeEmptyAndTrim(line.split(spiltRegex)));37 }38 }39 removeBomHead();40 returntextLines;41 }42

43 private voidgetOutPath(String srcPath) {44 int dotPosition = srcPath.lastIndexOf(".");45 outPath = srcPath.substring(0, dotPosition) + FILENAME_POSTFIX +srcPath.substring(dotPosition);46 if (newFile(outPath).exists()) {47 getOutPath(outPath);48 }49 }50

51 privateString[] removeEmptyAndTrim(String[] src) {52 for (int i = 0; i < src.length; i++) {53 src[i] =src[i].trim();54 }55

56 List dest = new ArrayList<>(Arrays.asList(src));57 dest.removeIf(String::isEmpty);58 return dest.toArray(new String[0]);59 }60

61 private voidremoveBomHead() {62 String[] blocks = textLines.get(0);63 blocks[0] = blocks[0].replace("\uFEFF", "");64 }65

66 void write() throwsIOException {67 try (BufferedWriter writer = new BufferedWriter(newFileWriter(outPath))) {68 for(String[] blocks : textLines) {69 writer.write(getLine(blocks));70 writer.newLine();71 writer.flush();72 }73 }74 }75

76 privateString getLine(String[] blocks) {77 StringBuilder sb = newStringBuilder();78 for(String block : blocks) {79 sb.append(block);80 }81 returnsb.toString();82 }83 }