Java

Java中调用DOS命令的问题

最近遇到一个问题，就是我的mail文件夹下面的mail太多了，使得Becky的浏览速度变得很慢，所以必须先备份原先的数据，但是又不能将目录结构删除，所以我想写一个java程序来完成这个工作。

刚开始我的思路是用java中出需要删除的文件或文件夹，保存在一个set中，然后对这个set进行遍历，每一项拼成一个DOS命令，然后用Runtime.getRuntime().exec()来运行，思路是对的，但是谁知道当要删除的文件很多的时候，Runtime.getRuntime().exec()产生的进程就会挂起，一直没有响应，我很郁闷，不知道是为什么，上网找资料也没有找到，所以另辟蹊径了。
将所有的命令输出到一个bat文件中，然后用Runtime.getRuntime().exec()来调用这个文件就解决问题了。
源代码如下：
有一些冗余的东西没有删除。
当然用别的语言也许更简单。

  1. package tools.deletefile;
  2. import java.io.BufferedReader;
  3. import java.io.BufferedWriter;
  4. import java.io.File;
  5. import java.io.FileWriter;
  6. import java.io.IOException;
  7. import java.io.InputStreamReader;
  8. import java.io.OutputStreamWriter;
  9. import java.io.PrintWriter;
  10. import java.util.HashSet;
  11. import java.util.Iterator;
  12. import java.util.Set;
  13. public class DeleteSpecialFile2{
  14. private static String batPath = System.getProperty( “user.dir” ) + File.separator + “deleteFile.bat” ;
  15. private BufferedWriter batFileOut;
    1. private static String mailPath = “@@/email/46d6483d.mb” ;
  17. private static String svnPath = “@@” ;
  18. private static String path = svnPath;
    1. private static String[] deleteFileExtension = new String[] { “.bmf” , “.java” , “.mf” , “.idx” };
  20. private static String[] deleteFolder = new String[] { “#Attach” };
    1. private Set s = new HashSet();
  22. private int deletedFileCount;
  23. private int deletedFolderCount;
    1. private StringBuffer deleteFileCommand = new StringBuffer();
  25. private StringBuffer deleteFolderCommand = new StringBuffer();
    1. public DeleteSpecialFile2(){
  27. }
    1. public void callBatFile(){
  29. //open bat file
  30. try {
  31. batFileOut = new BufferedWriter( new FileWriter(batPath));
  32. generateBatFile();
  33. batFileOut.flush();
  34. batFileOut.close();
  35. } catch (IOException e) {
  36. e.printStackTrace();
  37. }
    1. System.out.println(batPath);
  39. runBat( “cmd.exe /c” + batPath);
  40. System.out.println(deletedFileCount + “ ‘s file is deleted.” );
  41. System.out.println(deletedFolderCount + “ ‘s folder is deleted.” );
  42. System.out.println( “Thank you for use! jialiang” );
  43. }
    1. public void runBat(String command){
  45. Process child = null ;
  46. try {
  47. Runtime rt = Runtime.getRuntime();
  48. child = rt.exec(command);
  49. String line = null ;
  50. BufferedReader reader = new BufferedReader( new InputStreamReader(child.getInputStream()));
  51. while ((line = reader.readLine()) != null ) {
  52. System.out.println(line);
  53. }
  54. reader.close();
  55. while ( true ) {
  56. if (child.waitFor() == 0 )
  57. break ;
  58. }
  59. } catch (Exception ex) {
  60. child.destroy();
  61. ex.printStackTrace();
  62. }
  63. }
    1. private void generateBatFile(){
  65. process( null );
  66. }
    1. public void process(PrintWriter out){
  68. try {
  69. scan( new String[] { path });
  70. } catch (IOException e) {
  71. e.printStackTrace();
  72. }
  73. for (Iterator iterator = s.iterator(); iterator.hasNext();) {
  74. String object = (String) iterator.next();
  75. if (isSuitableFileExtension(object)) {
  76. deleteFile2(object, out);
  77. }
  78. if (isSuitableFolder(object)) {
  79. deleteFolder2(object, out);
  80. }
  81. }
  82. }
    1. private void scan(String[] strings) throws IOException{
  84. File telegramPath;
  85. String[] fileNames;
  86. telegramPath = new File(strings[ 0 ]);
  87. fileNames = telegramPath.list();
  88. for ( int i = 0 ; i < fileNames.length; i++) {
  89. File f = new File(telegramPath.getPath(), fileNames[i]);
  90. if (f.isDirectory()) {
  91. if (isSuitableFolder(f.getCanonicalPath())) {
  92. s.add(f.getCanonicalPath());
  93. } else {
  94. scan( new String[] { f.getPath() });
  95. }
  96. } else if (f.isFile()) {
  97. s.add(f.getCanonicalPath());
  98. }
  99. }
  100. }
    1. private boolean isSuitableFileExtension(String fileName){
  102. boolean result = false ;
  103. for ( int i = 0 ; i < deleteFileExtension.length; i++) {
  104. if (fileName.endsWith(deleteFileExtension[i])) {
  105. result = true ;
  106. break ;
  107. }
  108. }
  109. return result;
  110. }
    1. private boolean isSuitableFolder(String fileName){
  112. boolean result = false ;
  113. for ( int i = 0 ; i < deleteFolder.length; i++) {
  114. if (fileName.endsWith(deleteFolder[i])) {
  115. result = true ;
  116. break ;
  117. }
  118. }
  119. return result;
  120. }
    1. private void deleteFile2(String target, PrintWriter out){
  122. String command = “del “ + target + “/n” ;
  123. System.out.print(command);
  124. try {
  125. batFileOut.write(command);
  126. } catch (IOException e) {
  127. e.printStackTrace();
  128. }
  129. deletedFileCount++;
  130. }
    1. private void deleteFolder2(String target, PrintWriter out){
  132. String command = “rd /s/q “ + target + “/n” ;
  133. System.out.print(command);
  134. try {
  135. batFileOut.write(command);
  136. } catch (IOException e) {
  137. e.printStackTrace();
  138. }
  139. deletedFolderCount++;
  140. }
    1. public static void main(String[] test){
  142. DeleteSpecialFile2 delete = new DeleteSpecialFile2();
  143. delete.callBatFile();
  144. }
  145. }