package com.xiaopeng.trafficControl.util;

import java.io.*;
import java.lang.reflect.Method;
import java.net.URL;

/**
 * 资源工具类
 * @author binghuoliu
 * 
 */
public class ResourceUtil {

	/**
	 * 读取classpath下的文件<br>
	 * 读取classpath下的文件 一般用于读取classpath下的配置文件,注意读取的配置文件路径是相对传入参数clazz的load入路径. 例：<br>
	 * ClassTest c1;//假设c1是从/usr/local/classpath/ 载入<br>
	 * ClassTest c2;//假设c2是从/home/classpath/ 载入<br>
	 * ............<br>
	 * loadConfigFile("a.xml",c1.class);//从/usr/local/classpath1/下寻找a.xml<br>
	 * loadConfigFile("a.xml",c2.class);//从/home/classpath/下寻找a.xml<br>
	 * @param resource 资源路径
	 * @param clazz
	 * @return InputStream 文件的inputstram,如果找不到则返回null
	 */
	@SuppressWarnings("unchecked")
	public static InputStream loadConfigFile(String resource, Class clazz) {
		ClassLoader classLoader = null;
		try {
			Method method = Thread.class.getMethod("getContextClassLoader");
			classLoader = (ClassLoader) method.invoke(Thread.currentThread());
		} catch (Exception e) {
			throw new RuntimeException("loadConfigFile error: ", e);
		}
		if (classLoader == null) {
			classLoader = clazz.getClassLoader();
		}
		try {
			if (classLoader != null) {
				URL url = classLoader.getResource(resource);
				if (url == null) {
					System.out.println("Can not find resource:" + resource);
					return null;
				}
				if (url.toString().startsWith("jar:file:")) {
					System.out.println("Get resource \"" + resource + "\" from jar:\t" + url.toString());
					return clazz.getResourceAsStream(resource.startsWith("/") ? resource : "/" + resource);
				} else {
					System.out.println("Get resource \"" + resource + "\" from:\t" + url.toString());
					return new FileInputStream(new File(url.toURI()));
				}
			}
		} catch (Exception e) {
			throw new RuntimeException("loadConfigFile error: ", e);
		}
		return null;
	}

	/**
	 * 释放资源（有异常抛出）
	 * @param closeable
	 * @throws IOException
	 */
	public static void close(Closeable closeable) throws IOException {
		if (closeable != null) {
			closeable.close();
		}
	}

	/**
	 * 以优雅的形式释放资源（内部吃掉了异常）
	 * @param closeable
	 */
	public static void closeGracefully(Closeable closeable) {
		if (closeable != null) {
			try {
				closeable.close();
			} catch (IOException e) {
			}
		}
	}
}