这是我使用的代码
删除和重命名目录中的大量文件。
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html; charset=UTF-8");
response.setCharacterEncoding("UTF-8");
RootSipResourceApp.updateRootFile(strDirectorypath, strappID, appNames);
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/index.jsp");
dispatcher.forward(request, response);
}
public static void updateRootFile(String directorypath, String appID, String[] appName)
throws IOException {
try {
FileInputStream fin = null;
File[] listOfFiles=fileLists(directorypath);
for (int i = 0; i < listOfFiles.length; i++) {
if (listOfFiles[i].isFile()) {
rootFiles = listOfFiles[i].getName();
if (rootFiles.endsWith(".properties") || rootFiles.endsWith(".PROPERTIES")) {
fin = new FileInputStream(directorypath + rootFiles);
properties.load(new InputStreamReader(fin, Charset.forName("UTF-8")));
String getAppName = properties.getProperty("root.label." + appID);
String propertyStr = "root.label." + appID;
saveFile(fin, getAppName, directorypath + rootFiles, propertyStr, appName[i]);
}
}
}
} catch (Exception e) {
System.out.println("expn-" + e);
}
}
public static void saveFile(FileInputStream fins, String oldAppName, String filePath, String propertyStr, String appName)
throws IOException {
String oldChar = propertyStr + "=" + oldAppName;
String newChar = propertyStr + "=" + appName;
String strLine;
File f1 = new File(filePath);
File f2 = new File("C:\\Equinox\\RootSipResource\\root\\root_created.properties");
BufferedReader br = new BufferedReader(new InputStreamReader( new FileInputStream(f1), "UTF-8"));
OutputStreamWriter out = new OutputStreamWriter(new FileOutputStream(f2), "UTF-8");
while ((strLine = br.readLine()) != null) {
strLine = strLine.replace(oldChar, newChar);
out.write(strLine);
out.write("\r\n");
}
out.flush();
out.close();
br.close();
fins.close();
}
最佳答案
选项 1:
将public static void updateRootFile
更改为public static synchronized void updateRootFile
选项 2:
添加成员到servlet类
private final static Object lock = new Object();
然后将 updateRootFile 方法中的代码包装到
synchronized(lock) {
....
}
不同之处在于选项 1 锁定整个 servlet 类(所有它的同步方法),而选项 2 允许从除 updateRootFile()
之外的其他线程调用其他 servlet 的方法
我相信最权威的指南之一 is here .第 07 - 11 章与多线程代码相关。
关于java - 如何防止多个 Servlet 线程同时访问静态方法,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8600827/