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package com.wichell.core.util;

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.CodeSource;
import java.security.ProtectionDomain;
import java.util.Collection;
import java.util.Map;

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;

/**
 * 常见的辅助类
 * 
 * @author Wichell
 * @since 2011-11-08
 */
public final class DataUtil {
	private DataUtil() {
	}

	/**
	 * 十进制字节数组转十六进制字符串
	 * 
	 * @param b
	 * @return
	 */
	public static final String byte2hex(byte[] b) { // 一个字节数，转成16进制字符串
		StringBuilder hs = new StringBuilder(b.length * 2);
		String stmp = "";
		for (int n = 0; n < b.length; n++) {
			// 整数转成十六进制表示
			stmp = Integer.toHexString(b[n] & 0XFF);
			if (stmp.length() == 1)
				hs.append("0").append(stmp);
			else
				hs.append(stmp);
		}
		return hs.toString(); // 转成大写
	}

	/**
	 * 十六进制字符串转十进制字节数组
	 * 
	 * @param b
	 * @return
	 */
	public static final byte[] hex2byte(String hs) {
		byte[] b = hs.getBytes();
		if ((b.length % 2) != 0)
			throw new IllegalArgumentException("长度不是偶数");
		byte[] b2 = new byte[b.length / 2];
		for (int n = 0; n < b.length; n += 2) {
			String item = new String(b, n, 2);
			// 两位一组，表示一个字节,把这样表示的16进制字符串，还原成一个十进制字节
			b2[n / 2] = (byte) Integer.parseInt(item, 16);
		}
		return b2;
	}

	/**
	 * 这个方法可以通过与某个类的class文件的相对路径来获取文件或目录的绝对路径。 通常在程序中很难定位某个相对路径，特别是在B/S应用中。
	 * 通过这个方法，我们可以根据我们程序自身的类文件的位置来定位某个相对路径。
	 * 比如：某个txt文件相对于程序的Test类文件的路径是../../resource/test.txt，
	 * 那么使用本方法Path.getFullPathRelateClass("../../resource/test.txt",Test.class)
	 * 得到的结果是txt文件的在系统中的绝对路径。
	 * 
	 * @param relatedPath
	 *            相对路径
	 * @param cls
	 *            用来定位的类
	 * @return 相对路径所对应的绝对路径
	 * @throws IOException
	 *             因为本方法将查询文件系统，所以可能抛出IO异常
	 */
	public static final String getFullPathRelateClass(String relatedPath, Class cls) {
		String path = null;
		if (relatedPath == null) {
			throw new NullPointerException();
		}
		String clsPath = getPathFromClass(cls);
		File clsFile = new File(clsPath);
		String tempPath = clsFile.getParent() + File.separator + relatedPath;
		File file = new File(tempPath);
		try {
			path = file.getCanonicalPath();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return path;
	}

	/**
	 * 获取class文件所在绝对路径
	 * 
	 * @param cls
	 * @return
	 * @throws IOException
	 */
	public static final String getPathFromClass(Class cls) {
		String path = null;
		if (cls == null) {
			throw new NullPointerException();
		}
		URL url = getClassLocationURL(cls);
		if (url != null) {
			path = url.getPath();
			if ("jar".equalsIgnoreCase(url.getProtocol())) {
				try {
					path = new URL(path).getPath();
				} catch (MalformedURLException e) {
				}
				int location = path.indexOf("!/");
				if (location != -1) {
					path = path.substring(0, location);
				}
			}
			File file = new File(path);
			try {
				path = file.getCanonicalPath();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return path;
	}

	/**
	 * 判断对象是否Empty(null或元素为0)

	 * 实用于对如下对象做判断:String Collection及其子类 Map及其子类
	 * 
	 * @param pObj
	 *            待检查对象
	 * @return boolean 返回的布尔值
	 */
	public static final boolean isEmpty(Object pObj) {
		if (pObj == null || "".equals(pObj))
			return true;
		if (pObj instanceof String) {
			if (((String) pObj).trim().length() == 0) {
				return true;
			}
		} else if (pObj instanceof Collection) {
			if (((Collection) pObj).size() == 0) {
				return true;
			}
		} else if (pObj instanceof Map) {
			if (((Map) pObj).size() == 0) {
				return true;
			}
		}
		return false;
	}

	/**
	 * 判断对象是否为NotEmpty(!null或元素>0)

	 * 实用于对如下对象做判断:String Collection及其子类 Map及其子类
	 * 
	 * @param pObj
	 *            待检查对象
	 * @return boolean 返回的布尔值
	 */
	public static final boolean isNotEmpty(Object pObj) {
		if (pObj == null || "".equals(pObj))
			return false;
		if (pObj instanceof String) {
			if (((String) pObj).trim().length() == 0) {
				return false;
			}
		} else if (pObj instanceof Collection) {
			if (((Collection) pObj).size() == 0) {
				return false;
			}
		} else if (pObj instanceof Map) {
			if (((Map) pObj).size() == 0) {
				return false;
			}
		}
		return true;
	}

	/**
	 * JS输出含有\n的特殊处理
	 * 
	 * @param pStr
	 * @return
	 */
	public static final String replace4JsOutput(String pStr) {
		pStr = pStr.replace("\r\n", "
  ");
		pStr = pStr.replace("\t", "    ");
		pStr = pStr.replace(" ", " ");
		return pStr;
	}

	/**
	 * 分别去空格
	 * 
	 * @param paramArray
	 * @return
	 */
	public static final String[] trim(String[] paramArray) {
		if (ArrayUtils.isEmpty(paramArray)) {
			return paramArray;
		}
		String[] resultArray = new String[paramArray.length];
		for (int i = 0; i < paramArray.length; i++) {
			String param = paramArray[i];
			resultArray[i] = StringUtils.trim(param);
		}
		return resultArray;
	}

	/**
	 * 获取类的class文件位置的URL
	 * 
	 * @param cls
	 * @return
	 */
	private static URL getClassLocationURL(final Class cls) {
		if (cls == null)
			throw new IllegalArgumentException("null input: cls");
		URL result = null;
		final String clsAsResource = cls.getName().replace('.', '/').concat(".class");
		final ProtectionDomain pd = cls.getProtectionDomain();
		if (pd != null) {
			final CodeSource cs = pd.getCodeSource();
			if (cs != null)
				result = cs.getLocation();
			if (result != null) {
				if ("file".equals(result.getProtocol())) {
					try {
						if (result.toExternalForm().endsWith(".jar") || result.toExternalForm().endsWith(".zip"))
							result = new URL("jar:".concat(result.toExternalForm()).concat("!/").concat(clsAsResource));
						else if (new File(result.getFile()).isDirectory())
							result = new URL(result, clsAsResource);
					} catch (MalformedURLException ignore) {
					}
				}
			}
		}
		if (result == null) {
			final ClassLoader clsLoader = cls.getClassLoader();
			result = clsLoader != null ? clsLoader.getResource(clsAsResource)
					: ClassLoader.getSystemResource(clsAsResource);
		}
		return result;
	}

	/** 初始化设置默认值 */
	public static final  K ifNull(K k, K defaultValue) {
		if (k == null) {
			return defaultValue;
		}
		return k;
	}
}