javapackageexplorer.java

ESQL包 PostgreSQL jsp servlet javaBean 数据库访问 存取数据

package com.dao;

import java.io.File;
import java.net.JarURLConnection;
import java.net.URI;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.Stack;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/** 包浏览器, 列出指定包即子包中所有类 */
public class JavaPackageExplorer
{
	private String name; // 包名

	public JavaPackageExplorer(String name)
	{
		this.name = name;
	}

	public List<String> explore() throws Exception
	{
		List<String> list = new ArrayList<String>();

		String s = name.replace('.', '/');
		for (Enumeration<URL> e = getClass().getClassLoader().getResources(s); e.hasMoreElements();)
		{
			URL url = e.nextElement();
			if (url.getProtocol().equals("jar"))
			{
				JarURLConnection con = (JarURLConnection) url.openConnection();
				JarFile file = con.getJarFile();
				list.addAll(listFromJarFile(file));
			}
			else
			{
				File file = new File(new URI(url.toExternalForm()));
				list.addAll(listFromFileSystem(file));
			}
		}

		return list;
	}

	private List<String> listFromJarFile(JarFile file)
	{
		List<String> list = new ArrayList<String>();
		for (Enumeration<JarEntry> je = file.entries(); je.hasMoreElements();)
		{
			JarEntry entry = je.nextElement();

			String s = entry.getName();
			if (!s.startsWith(name)) continue;
			if (!s.endsWith(".class")) continue;

			s = s.substring(0, s.length() - 6).replace('/', '.');
			list.add(s);
		}

		return list;
	}

	private List<String> listFromFileSystem(File path)
	{
		List<String> list = new ArrayList<String>();

		int n = path.getAbsolutePath().length() - name.length();
		Stack<File> stack = new Stack<File>();

		stack.push(path);
		while (!stack.isEmpty())
		{
			File file = stack.pop();
			if (file.isFile())
			{
				String s = file.getAbsolutePath();
				if (!s.endsWith(".class")) continue;
				s = s.substring(n, s.length() - 6).replaceAll("[/\\\\]", ".");
				list.add(s);
				continue;
			}

			if (file.isDirectory())
			{
				File[] files = file.listFiles();
				for (int i = 0; i < files.length; i++)
				{
					stack.push(files[i]);
				}
			}
		}

		return list;
	}
}