617
京東網上商城
抽象模型，嚴謹代碼，開源分享
前言首先，感謝Eric對我代碼上的建議，感謝Stone在FTP Lab環境部署上對我的指導。
今年4月份的時候，做了一個小的項目，當時也沒有去總結整理，現在想想總結整理是很有必要的，這也是一個很好的工作研究的習慣。
關於項目，不論大小，其實做到極致也不是一件容易的事。隻有做到極致，才算真正的項目經驗；隻有做到極致，才能讓編程真正成為一門藝術；隻有體會編程是一門有趣的藝術時，你的職業生涯才經久不衰，常青不老。
當然，我現在也隻是一個走在編程藝術道路上的小孩，不停探索，充滿好奇，我也希望誌同道合的同仁們給我指教與分享。
我相信，隻有開源了，才會有更多更大的進步，才會有活力，有創造力。我支持開源與自由，我唾棄陳舊死板的開發與管理！
項目簡介
略......
編程點滴
1. 同樣一個文件能隻打開一次搞定的，就隻打開一次，避免頻繁的I/O流操作。比如：讀一個屬性文件，文件中有很多屬性項目，我們可以將屬性項預定義在一個數組裏，當打開屬性文件時，遍曆屬性數組，將得到的屬性鍵值對預存在一個哈希表裏，這樣之後在用到屬性值時，隻需從哈希表裏獲取就可以了。
String[] propertyArray = new String[] { "templateDirectory", "sourceDirectory", "cm",
"filereadyfile", "xmlCMIRPVersion", "expireHour",
"meLimitCount", "fileNamePrefix", "subObjectLimitCount" };
Map<String, String> propertyMap = CommonTool.getPropertyMap(ConstantPool.CM_CONFIGRATION_FILE, propertyArray);
public static Map<String, String> getPropertyMap(String cmccCmConfigurationFile, String[] propertyArray) {
InputStream inputStream = null;
Map<String, String> propertyMap = new HashMap<String, String>();
int propertyArrayLength = propertyArray.length;
Properties properties = new Properties();
try {
inputStream = Files.newInputStream(Paths.get(cmccCmConfigurationFile));
properties.load(inputStream);
} catch (IOException ioe) {
LOG.error(ioe.getMessage());
ioe.printStackTrace();
} finally {
IOUtils.closeQuietly(inputStream);
}
for (int index = 0; index < propertyArrayLength; index++) {
String propertyName = propertyArray[index];
String propertyValue = properties.getProperty(propertyName);
if (StringUtils.trimToEmpty(propertyValue).equals("")) {
throw new NullPointerException("There is no property " + propertyName + " in the configuration file " + cmccCmConfigurationFile);
} else {
propertyValue = StringUtils.trim(propertyValue);
}
propertyMap.put(propertyName, propertyValue);
}
return propertyMap;
}
2. 我們能計算一次搞定的，就隻計算一次，比如：我們會經常遍曆數組，往往會讓數組長度的計算在循環中計算多次，這是低效的。
int propertyArrayLength = propertyArray.length;
for (int index = 0; index < propertyArrayLength; index++) {
......
}
for (int index = 0; index < propertyArray.length; index++) {
......
}
3. 我們處理屬性文件時，一定要嚴謹，比如：有個屬性項是表示數量的，當我們獲取到該屬性項時，我們要對其進行數字正則判斷，要不然你得到一個非數字的屬性，你怎麼拿來運算？
public static boolean isDigit(String str) {
boolean isDigitFlag = false;
if (str.matches("(^[-|+]?)\\d+")) {
isDigitFlag = true;
}
return isDigitFlag;
}
4. 我們經常會拚湊，傳參等方式來定義文件名，所以在這種情況下，有必要對文件名合法性與否作出正則判斷。
public static boolean isInvalidFileName(String fileName) {
boolean isInvalidFileNameFlag = false;
if (fileName.matches(".*[\\/:\\*\\?\"<>\\|].*")) {
isInvalidFileNameFlag = true;
}
return isInvalidFileNameFlag;
}
5. 我們對特殊字符的處理，也要嚴謹，考慮方方麵麵，比如：在文件中將'&'轉換成'&'，'<'轉換成'<'，'>'轉換成'>'，在這種情況下，你就不能將'&'和'<'，以及'>'中的'&'再轉換成'&'了。
public static String replaceReserveSymbel(String convertPartStr) {
if (convertPartStr != null) {
if (convertPartStr.contains("&")) {
StringBuffer sb = new StringBuffer("");
convertPartStr = replaceReserveSymbel(convertPartStr, sb);
}
convertPartStr = convertPartStr.replace("<", "<");
convertPartStr = convertPartStr.replace(">", ">");
convertPartStr = convertPartStr.replace("\\", "\\\\");
convertPartStr = convertPartStr.replace("{", "\\{");
convertPartStr = convertPartStr.replace("}", "\\}");
convertPartStr = convertPartStr.replace("(", "\\(");
convertPartStr = convertPartStr.replace(")", "\\)");
convertPartStr = convertPartStr.replace(",", "\\,");
}
return convertPartStr;
}
public static String replaceReserveSymbel(String convertPartStr, StringBuffer sb) {
int index = convertPartStr.indexOf("&");
String leftStr = "";
String rightStr = "";
if (index >= 0) {
leftStr = convertPartStr.substring(0, index + 1);
rightStr = convertPartStr.substring(index + 1);
sb.append(leftStr);
if (!rightStr.startsWith("amp;") && !rightStr.startsWith("lt;") && !rightStr.startsWith("gt;")) {
sb.append("amp;");
}
replaceReserveSymbel(rightStr, sb);
} else {
sb.append(convertPartStr);
}
return sb.toString();
}
6. 在多線程編程中，我們很多時候要實現接口Callable<?>, 而非實現接口Runnable,接口Callable<?>給我們帶來的方便是不言而喻的，因為，可以重寫它的方法call()，獲得我們想要的返回值。
/**
* @author shengshu
*
*/
public class ConverterTask implements Callable<File> {
private static final Logger LOG = Logger.getLogger(ConverterTask.class);
private File templateFile = null;
private File fragmentFile = null;
private String exportDirectoryStr = null;
private String notificationDirectoryStr = null;
public String fileNamePrefix = null;
private static final Date date = new Date();
public ConverterTask(File fragmentFile, File templateFile, String destDirectoryStr, String notificationDirectoryStr, String fileNamePrefix) {
this.fragmentFile = fragmentFile;
this.templateFile = templateFile;
this.exportDirectoryStr = destDirectoryStr;
this.notificationDirectoryStr = notificationDirectoryStr;
this.fileNamePrefix = fileNamePrefix;
}
public File convertFile(File fragmentFile, File templateFile, String exportDirectoryStr, String notificationDirectoryStr, String fileNamePrefix) {
......
return exportFile;
}
public void convertFile(File fragmentFile, File templateFile, File exportDirectory, File notificationDirectory, String fileNamePrefix) throws Throwable {
convertFile(fragmentFile, templateFile, exportDirectory.getAbsolutePath(), notificationDirectory.getAbsolutePath(), fileNamePrefix);
}
@Override
public File call() throws Exception {
File exportFile = convertFile(fragmentFile, templateFile, exportDirectoryStr, notificationDirectoryStr, fileNamePrefix);
return exportFile;
}
}
private static void initConverter() {
LOG.info("Converter thread pool size: " + threadPoolSize);
converterThreadPool = Executors.newFixedThreadPool(threadPoolSize);
converterFutureList = new ArrayList<Future<File>>();
if (sourceDirectory != null && sourceDirectory.isDirectory()) {
fragmentFileCollection = FileUtils.listFiles(sourceDirectory, new String[] { "xml", "XML" }, false);
} else {
LOG.warn("The directory " + sourceDirectoryStr + " doesn't exist or is invalid!");
}
if (templateDirectory != null && templateDirectory.isDirectory()) {
templateFileCollection = FileUtils.listFiles(templateDirectory, new String[] { "xsl", "XSL" }, false);
} else {
LOG.warn("The directory " + templateDirectoryStr + " doesn't exist or is invalid!");
}
}
public void converter() {
LOG.info("==================Converter Start==================");
startTime = System.currentTimeMillis();
initConverter();
if ((fragmentFileCollection != null && !fragmentFileCollection.isEmpty()) && (templateFileCollection != null && !templateFileCollection.isEmpty())) {
Iterator<File> fragmentFileIterator = fragmentFileCollection.iterator();
while (fragmentFileIterator.hasNext()) {
File fragmentFile = fragmentFileIterator.next();
LOG.info("Fragment file: " + fragmentFile);
Iterator<File> templateFileIterator = templateFileCollection.iterator();
while (templateFileIterator.hasNext()) {
File templateFile = templateFileIterator.next();
LOG.info("Template file: " + templateFile);
ConverterTask converterTask = new ConverterTask(fragmentFile, templateFile, exportDirectoryStr, notificationDirectoryStr, fileNamePrefix);
Future<File> converterFuture = converterThreadPool.submit(converterTask);
converterFutureList.add(converterFuture);
}
}
}
destroyConverter();
endTime = System.currentTimeMillis();
deltaTime = endTime - startTime;
LOG.info("Converter spend " + deltaTime / 1000 + " seconds");
LOG.info("==================Converter End==================");
}
private static void destroyConverter() {
LOG.info("===Start to destroy thread pool and delete files under source directory===");
for (Future<File> future : converterFutureList) {
try {
File exportFile = future.get();
if (exportFile.exists()) {
LOG.info("Invoke method call() and return : " + exportFile);
exportFileCollection.add(exportFile);
}
} catch (InterruptedException ie) {
ie.printStackTrace();
} catch (ExecutionException ee) {
ee.printStackTrace();
}
}
converterThreadPool.shutdown();
LOG.info("Thread pool is changed as status: SHUTDOWN");
while (!converterThreadPool.isTerminated())
;
LOG.info("Thread pool is changed as status: STOP");
if (!CommonTool.deleteFileCollection(fragmentFileCollection)) {
LOG.error("Fail to delete fragment files under directory " + sourceDirectoryStr);
}
LOG.info("===End to destroy thread pool and delete files under source directory===");
}
7. 我們會經常處理多線程，高並發的問題，往往會用到線程池，所以我們既要保證任務都能被執行，又能保證線程池正常終止。
subSpliterThreadPool.shutdown();
while (!subSpliterThreadPool.isTerminated())
;
8. 在處理XML文件時，對XSLT的應用將會大大簡化我們的代碼邏輯與數量，實現代碼與文本處理的解耦。
最後更新：2017-04-03 07:57:00