用JAVA写了一个简单的JS代码格式化工具

Section I: 为什么写这个小玩意
1. 手上有些JS代码，因为某种原因，起代码中没有任何回车、制表符。在编辑器中打开时，显示的就是一行。而我实现想研究和学习这些写得比较漂亮的JS代码，
2. 可是好想没有哪个编辑器自带了JS格式化的功能。它们都可以给JS着色，但就是不能控制代码格式，真是遗憾。
3. 我是我去网上搜看有没有前人做过这个东东，发现有个JS写的JS代码格式化工具，相当不错，可以给代码格式化，还可以着色。只不过结果都是显示在网页上，复制下来的时候那些制表符都没有了，所以贴到编辑器中时，代码还是比较混乱；而且这个每次只能格式话一个文件，还得自己手动去Copy & paste；而且因为是JS写的，速度也受到了不小的限制；
基于以上原因，我准备自己些一个小工具来格式化我需要的代码：

Section II: 功能
1. 因为很多编辑器都有JS的着色功能，所一我需要的仅仅是一个格式化功能而已，那就是主要将那种故意将代码中的空白符去掉的的JS加上换行、制表符等等。
大概有一下几种情况：
1). add /n/n before "function";
2). add /n after ";" (Except "for", and ";" between " " which is part of a string in javascript. ) and /t before the next line;
3）. add "/n" and "/t" after "{";
4). add "/n" and "/t" before "}".
2. 不仅可以格式话一个给定的文件，还可以格式化给定的一个文件夹里的所有的JS文件。这个就是通过传给Main函数的参数来实现的。参数可以如下：
1）格式化一个文件：
    -f path/file.js
或者：
    --file path/file.js
2) 格式化给定的一个文件夹里的所有的JS文件
    -d path/directory
或者：
    --directory path/directory

举例：要格式化/home/newweapon/js/ 这个文件夹中的所有JS文件，可一使用如下命令：
JsFormatter -d /home/newweapon/js

Section III 缺陷
目前写的这个程序还是一个比较脆弱的程序。有很多情况没有考虑到，我在注释中把我想到的需要提高的基本都提了一下。但是因为我写这个小玩意主要是想把我自己下的一些JS代码格式化一下，而这个对我来说已经够用了，再加上自己的水平有限，所以没有将它写得很完美。等以后有时间了，再对这个程序做一些更新。

Section IV 代码

/**
* cn.newweapon.JsFormatter
*/
package cn.newweapon;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.FilenameFilter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Pattern;

/**
* @author Newweapon @ ustc [Email: newweapon111 (at) gmail.com]
* @version 0.0.1
* @Created 20071015
*
* @TODO 1. user can specify the formatted file name; 
* 2. User can located the formatted files to a specified folder. 
* 3. If a file is formatted partly already. Delete all blank characters first, and then format the file. 
*/
public class JsFormatter {

 /* ============ constants begin =================== */
 /** Usage */
 public static String USAGE = " Usage: JsFormatter -d path/directory JsFormatter -f path/filename.js " ;

 /** Type: Directory = "0"; File = "1" */
 public interface Type {
 /** Directory: 0 */
 public static String DIRECTORY = " 0 " ;
 /** File: 1 */
 public static String FILE = " 1 " ;
 }
 /* ============ constants end =================== */

 /**
 * Entry point of the project.
 *
 * @param args Like "-d /path/directory" or "-f /path/file.js"
 */
 public static void main(String[] args) {
 String startMsg = " Processing... " ;
 String finishMsg = " Finished. " ;

 // Parameters check.
 if (args.length != 2 ) {
 System.err.println(USAGE);
 return ;
 }
 // Get the two parameters.
 String type = args[ 0 ];
 String path = args[ 1 ];
 // Parameters check.
 if ( " -d " .equals(type) || " --directory " .equals(type)) {
 type = Type.DIRECTORY;
 } else if ( " -f " .equals(type) || " --file " .equals(type)) {
 type = Type.FILE;
 } else {
 System.err.println(USAGE);
 return ;
 }
 // Check file type
 if (Type.FILE.equals(type)) {
 if (path.length() <= 3 || ! isJsFile(path)) {
 System.err.println( " The file must be a JS file. " );
 return ;
 }
 }

 // Start message
 System.out.println(startMsg);

 // Format file(s)
 try {
 if (Type.FILE.equals(type)) {
 formatFile(path);
 } else {
 List < String > jsFileList = getJsFileList(path);
 Iterator < String > it = jsFileList.iterator();
 while (it.hasNext()) {
 formatFile(it.next());
 }
 finishMsg += " ( " + jsFileList.size() + " file(s) formatted) " ;
 }
 } catch (Exception e) {
 e.printStackTrace();
 return ;
 }

 // Finish message
 System.out.println(finishMsg);
 }

 /**
 * Format a JS file.
 *
 * @param fileName The file name of the file which is to be formatted.
 * @return String The formatted string.
 * @throws IOException Exception when open, read and write file.
 */
 private static void formatFile(String fileName) throws IOException {
 String formattedFileName = fileName + " .formatted " ;

 FileReader fr = new FileReader(fileName);
 FileWriter fw = new FileWriter(formattedFileName);

 String lastWord = "" ;

 int forCount = 0 ;
 int quoteCount = 0 ;
 int sigleQuoteCount = 0 ;
 int bracketCount = 0 ;

 int thisChar = 0 ;
 int lastChar = 0 ;
 int nextChar = 0 ;

 thisChar = fr.read();
 if (thisChar != - 1 ) {
 nextChar = fr.read();
 }

 while (thisChar != - 1 ) {
 // find and replace
 switch (thisChar) {
 // 2. add after ";" (Except "for", and ";" between " " which is part of a string in javascript. ) and before the next line
 case ' ; ' :
 // If the ";" is in quote or in "for", then not print " "
 if (quoteCount > 0 || sigleQuoteCount > 0 || forCount > 0 ) {
 fw.write( ' ; ' );
 if (forCount > 0 ) {
 forCount -- ;
 }
 // Add " " after ";"
 } else {
 fw.write( ' ; ' );
 if ( ' ' != nextChar && ' ' != nextChar) {
 fw.write( ' ' );
 fillTableChar(fw, bracketCount);
 }
 }
 break ;
 case ' { ' : // 3. add " " and " " after "{"
 bracketCount ++ ;
 fw.write( ' { ' );
 if ( ' ' != nextChar && ' ' != nextChar) { // If the file is already formatted, don't add after {.
 fw.write( ' ' );
 fillTableChar(fw, bracketCount);
 }
 break ;
 case ' } ' : // 4. add " " and " " before "}"
 bracketCount -- ;
 fw.write( ' ' );
 fillTableChar(fw, bracketCount);
 fw.write( ' } ' );
 if ( ' ; ' != nextChar && ' } ' != nextChar && ' ' != nextChar && ' ' != nextChar) {
 fw.write( ' ' );
 fillTableChar(fw, bracketCount);
 }
 break ;
 case ' ' ' :
 fw.write( ' ' ' );
 if (quoteCount == 0 ) { // When ' is not between "", change its state.
 sigleQuoteCount = sigleQuoteCount == 0 ? 1 : 0 ;
 }
 break ;
 case ' " ' :
 fw.write( ' " ' );
 if (sigleQuoteCount == 0 ) { // When ' is not between "", change its state.
 quoteCount = quoteCount == 0 ? 1 : 0 ;
 }
 break ;
 case ' f ' : // 1. add before "function"
 if (nextChar == ' u ' && lastChar != ' = ' ) { // TODO This is a very weak way to determine whether this coming word is "function", so it is need to be fixed.
 fw.write( ' ' );
 fw.write( ' ' );
 }
 fw.write( ' f ' );
 break ;
 default :
 fw.write(thisChar);
 break ;
 }

 if (isAlpha(thisChar)) {
 if ( ! isAlpha(lastChar)) {
 lastWord = "" ;
 }
 lastWord += String.valueOf(thisChar);
 } else {
 if (isAlpha(lastChar)) {
 if ( " 102111114 " .equals(lastWord)) { // "for"
 forCount = 2 ;
 }
 // TODO Whether is is suitable here to determine "function" and add " " before it?
 } else {
 lastWord = String.valueOf(thisChar);
 }
 }

 lastChar = thisChar;
 thisChar = nextChar;
 if (thisChar != - 1 ) {
 nextChar = fr.read();
 }
 }

 // close the files
 fw.close();
 fr.close();
 }

 /**
 * Find all JS files in the specified directory.
 *
 * @param directory The directory in which the files to be listed.
 * @return List<String> The JS file list.
 */
 private static List < String > getJsFileList(String directory) {
 List < String > jsFileList = new ArrayList < String > ();
 list(directory, jsFileList);
 return jsFileList;
 }

 /**
 * List all the JS files in the specified directory recursively.
 *
 * @param path The path to be recursively searched for JS files.
 * @param result The path and file list
 */
 private static void list(String path, List < String > result) {
 File f = new File(path);
 if (f.isDirectory()) {
 File[] fileList = f.listFiles();
 for ( int i = 0 ; i < fileList.length; i ++ ) {
 list(fileList[i].getPath(), result);
 }
 } else {
 if (isJsFile(f.getName())) {
 result.add(f.getPath());
 }
 }
 }

 /**
 * Determine whether the the specified file is a JS file.
 *
 * @param fileName
 * @return True: is a JS file; False: not a JS file.
 */
 private static boolean isJsFile(String fileName) {
 // TODO use pattern!!!
 return " .js " .equals(fileName.substring(fileName.length() - 3 ));
 }

 /**
 * List all JS files in the specified directory(Not in their sub-directory).
 *
 * @param dir The specified directory.
 * @return String[] The JS file list.
 */
 private static String[] getSingleDirJsFileList( final String dir) {
 String[] jsFileList;
 File path = new File(dir);
 jsFileList = path.list( new FilenameFilter() {
 private Pattern pattern = Pattern.compile( " .js " );
 public boolean accept(File dir, String name) {
 return pattern.matcher( new File(name).getName()).matches();
 }
 });
 return jsFileList;
 }

 /**
 * Check whether the character is an alpha char.
 * <red>Actually, the words exist in a function name would not be limit among those we list below.
 * This need to be fixed. </red>
 *
 * @param c The char to be checked.
 * @return boolean True: is alpha char; False: is not alpha char.
 */
 private static boolean isAlpha( int c) {
 return ((c > ' a ' && c < ' z ' ) || (c > ' A ' && c < ' Z ' ) || (c > ' 0 ' && c < ' 9 ' ));
 }

 /**
 * Fill specified number of ' '
 *
 * @param fw FileWriter
 * @param charNum Specified number of ' '
 * @throws IOException Exception when writing file
 */
 private static void fillTableChar(FileWriter fw, int charNum) throws IOException {
 for ( int i = 0 ; i < charNum; i ++ ) {
 fw.write( ' ' );
 }
 }
}

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用JAVA写了一个简单的JS代码格式化工具

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