velocity-web模板工具

package com.liuxiang.velocity.util; import java.io.File; import java.io.FileFilter; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; public class _ClassUtils { private static final String CLASS_EXT = ".class"; private static final String JAR_FILE_EXT = ".jar"; private static final String ERROR_MESSAGE = "packageName can't be null"; private static final String DOT = "."; private static final String ZIP_SLASH = "/"; private static final String BLACK = ""; private static final ClassFilter NULL_CLASS_FILTER = null; /**(1) 文件过滤器，过滤掉不需要的文件**/ private static FileFilter fileFilter = new FileFilter() { public boolean accept(File pathname) { return isClass(pathname.getName()) || isDirectory(pathname) || isJarFile(pathname.getName()); } }; /** * 如果packageName为空，就抛出空指针异常。</br> * (本工具类有一个bug，如果扫描文件时需要一个包路径为截取字符串的条件，现在还没有修复,所以加上该条件) * * @param packageName */ private static void ckeckNullPackageName(String packageName) { if (packageName == null || packageName.trim().length() == 0) throw new NullPointerException(ERROR_MESSAGE); } /** * 改变 com -> com. 避免在比较的时候把比如 completeTestSuite.class类扫描进去，如果没有. * </br>那如果class里面由一个com也会被扫描进去 * 其实就是包名称后面或前面需要一个 . * @param packageName * @return */ private static String getWellFormedPackageName(String packageName) { return packageName.lastIndexOf(DOT) != packageName.length() - 1 ? packageName + DOT : packageName; } /** * 扫面包路径下满足class过滤器条件的所有class文件，</br> 如果包路径为 com.abs + A.class * 但是输入 abs 会产生classNotFoundException</br> 因为className 应该为 com.abs.A 现在却成为 * abs.A,此工具类对该异常进行忽略处理,有可能是一个不完善的地方，以后需要进行修改</br> * @param packageName 包路径 com | com. | com.abs | com.abs. * @param classFilter class过滤器，过滤掉不需要的class * @return */ public static List<Class> scanPackage(String packageName,ClassFilter classFilter) { //检测packageName 是否为空，如果为空就抛出NullPointException ckeckNullPackageName(packageName); //实例化一个篮子 P: 放置class final List<Class> classes = new ArrayList<Class>(); // 遍历在classpath 下面的jar包，class文件夹(现在没有包括 java jre) for (String classPath : getClassPathArray()) { // 填充 classes fillClasses(new File(classPath), getWellFormedPackageName(packageName),classFilter, classes); } return classes; } /** * 扫面改包路径下所有class文件 * @param packageName 包路径 com | com. | com.abs | com.abs. * @return */ public static List<Class> scanPackage(String packageName) { return scanPackage(packageName, NULL_CLASS_FILTER); } /** * 填充满足条件的class 填充到 classes * * @param file 类路径下的文件 * @param packageName 需要扫面的包名 * @param classFilter class过滤器 * @param classes List 集合 */ private static void fillClasses(File file, String packageName,ClassFilter classFilter, List<Class> classes) { if (isDirectory(file)) { processDirectory(file, packageName, classFilter, classes); } else if (isClass(file.getName())) { processClassFile(file, packageName, classFilter, classes); } else if (isJarFile(file.getName())) { processJarFile(file, packageName, classFilter, classes); } } /** * 处理如果为目录的情况,需要递归调用 fillClasses方法 * * @param directory * @param packageName * @param classFilter * @param classes */ private static void processDirectory(File directory, String packageName,ClassFilter classFilter, List<Class> classes) { for (File file : directory.listFiles(fileFilter)) { fillClasses(file, packageName, classFilter, classes); } } /** * 处理为class文件的情况,填充满足条件的class 到 classes * * @param file * @param packageName * @param classFilter * @param classes */ private static void processClassFile(File file, String packageName,ClassFilter classFilter, List<Class> classes) { final String filePathWithDot = file.getAbsolutePath().replace(File.separator, DOT); int subIndex = -1; if ((subIndex = filePathWithDot.indexOf(packageName)) != -1) { final String className = filePathWithDot.substring(subIndex).replace(CLASS_EXT, BLACK); fillClass(className, packageName, classes, classFilter); } } /** * 处理为jar文件的情况，填充满足条件的class 到 classes * * @param file * @param packageName * @param classFilter * @param classes */ private static void processJarFile(File file, String packageName,ClassFilter classFilter, List<Class> classes) { try { for (ZipEntry entry : Collections.list(new ZipFile(file).entries())) { if (isClass(entry.getName())) { final String className = entry.getName().replace(ZIP_SLASH, DOT).replace(CLASS_EXT, BLACK); fillClass(className, packageName, classes, classFilter); } } } catch (Exception ex) { } } /** * 填充class 到 classes * * @param className * @param packageName * @param classes * @param classFilter */ private static void fillClass(String className, String packageName,List<Class> classes, ClassFilter classFilter) { if (checkClassName(className, packageName)) { try { final Class clazz = Class.forName(className, Boolean.FALSE,_ClassUtils.class.getClassLoader()); if (checkClassFilter(classFilter, clazz)) { classes.add(clazz); } } catch (ClassNotFoundException ex) { } } } private static String[] getClassPathArray() { // System.getProperty("java.home"); 不包括 jre return System.getProperty("java.class.path").split(System.getProperty("path.separator")); } private static boolean checkClassName(String className, String packageName) { return className.indexOf(packageName) == 0; } private static boolean checkClassFilter(ClassFilter classFilter, Class clazz) { return classFilter == NULL_CLASS_FILTER || classFilter.accept(clazz); } private static boolean isClass(String fileName) { return fileName.endsWith(CLASS_EXT); } private static boolean isDirectory(File file) { return file.isDirectory(); } private static boolean isJarFile(String fileName) { return fileName.endsWith(JAR_FILE_EXT); } }