Property文件以字符串形式保存数据。

这个类可以从Property文件中读取各种转换后的常见对象，可以继续扩展。

package com.arui.util;import java.io.File;import java.net.InetAddress;import java.net.UnknownHostException;import java.text.DateFormat;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Properties;import java.util.TimeZone;public class PropertiesUtil extends Properties {	private static final long serialVersionUID = -1810519669397594359L;	/**	 * Default constructor.	 */	public PropertiesUtil() {	}	/**	 * Load existing property.	 */	public PropertiesUtil(final Properties prop) {		super(prop);	}	/**	 * Get boolean value.	 */	public boolean getBoolean(final String str) throws Exception {		String prop = getProperty(str);		if (prop == null) {			throw new Exception(str + " not found");		}		return prop.toLowerCase().equals("true");	}	/**	 * Get boolean value.	 */	public boolean getBoolean(final String str, final boolean bol) {		try {			return getBoolean(str);		} catch (Exception ex) {			return bol;		}	}	/**	 * Get integer value.	 */	public int getInteger(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		try {			return Integer.parseInt(value);		} catch (NumberFormatException ex) {			throw new Exception("PropertiesUtil.getInteger()", ex);		}	}	/**	 * Get integer value.	 */	public int getInteger(final String str, final int intVal) {		try {			return getInteger(str);		} catch (Exception ex) {			return intVal;		}	}	/**	 * Get long value.	 */	public long getLong(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		try {			return Long.parseLong(value);		} catch (NumberFormatException ex) {			throw new Exception("PropertiesUtil.getLong()", ex);		}	}	/**	 * Get long value.	 */	public long getLong(final String str, final long val) {		try {			return getLong(str);		} catch (Exception ex) {			return val;		}	}	/**	 * Get double value.	 */	public double getDouble(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		try {			return Double.parseDouble(value);		} catch (NumberFormatException ex) {			throw new Exception("PropertiesUtil.getDouble()", ex);		}	}	/**	 * Get double value.	 */	public double getDouble(final String str, final double doubleVal) {		try {			return getDouble(str);		} catch (Exception ex) {			return doubleVal;		}	}	/**	 * Get InetAddress.	 */	public InetAddress getInetAddress(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		try {			return InetAddress.getByName(value);		} catch (UnknownHostException ex) {			throw new Exception("Host " + value + " not found");		}	}	/**	 * Get InetAddress.	 */	public InetAddress getInetAddress(final String str, final InetAddress addr) {		try {			return getInetAddress(str);		} catch (Exception ex) {			return addr;		}	}	/**	 * Get String.	 */	public String getString(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		return value;	}	/**	 * Get String.	 */	public String getString(final String str, final String s) {		try {			return getString(str);		} catch (Exception ex) {			return s;		}	}	/**	 * Get File object.	 */	public File getFile(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		return new File(value);	}	/**	 * Get File object.	 */	public File getFile(final String str, final File fl) {		try {			return getFile(str);		} catch (Exception ex) {			return fl;		}	}	/**	 * Get Class object	 */	public Class
     getClass(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		try {			return Class.forName(value);		} catch (ClassNotFoundException ex) {			throw new Exception("PropertiesUtil.getClass()", ex);		}	}	/**	 * Get Class object	 */	public Class
     getClass(final String str, final Class
     cls) {		try {			return getClass(str);		} catch (Exception ex) {			return cls;		}	}	/**	 * Get TimeZone	 */	public TimeZone getTimeZone(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		return TimeZone.getTimeZone(value);	}	/**	 * Get TimeZone	 */	public TimeZone getTimeZone(final String str, final TimeZone tz) {		try {			return getTimeZone(str);		} catch (Exception ex) {			return tz;		}	}	/**	 * Get DateFormat object.	 */	public SimpleDateFormat getDateFormat(final String str) throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		try {			return new SimpleDateFormat(value);		} catch (IllegalArgumentException e) {			throw new Exception("Date format was incorrect: " + value, e);		}	}	/**	 * Get DateFormat object.	 */	public SimpleDateFormat getDateFormat(final String str,			final SimpleDateFormat fmt) {		try {			return getDateFormat(str);		} catch (Exception ex) {			return fmt;		}	}	/**	 * Get Date object.	 */	public Date getDate(final String str, final DateFormat fmt)			throws Exception {		String value = getProperty(str);		if (value == null) {			throw new Exception(str + " not found");		}		try {			return fmt.parse(value);		} catch (ParseException ex) {			throw new Exception("PropertiesUtil.getdate()", ex);		}	}	/**	 * Get Date object.	 */	public Date getDate(final String str, final DateFormat fmt, final Date dt) {		try {			return getDate(str, fmt);		} catch (Exception ex) {			return dt;		}	}	/**	 * Set boolean value.	 */	public void setProperty(final String key, final boolean val) {		setProperty(key, String.valueOf(val));	}	/**	 * Set integer value.	 */	public void setProperty(final String key, final int val) {		setProperty(key, String.valueOf(val));	}	/**	 * Set double value.	 */	public void setProperty(final String key, final double val) {		setProperty(key, String.valueOf(val));	}	/**	 * Set float value.	 */	public void setProperty(final String key, final float val) {		setProperty(key, String.valueOf(val));	}	/**	 * Set long value.	 */	public void setProperty(final String key, final long val) {		setProperty(key, String.valueOf(val));	}	/**	 * Set InetAddress.	 */	public void setInetAddress(final String key, final InetAddress val) {		setProperty(key, val.getHostAddress());	}	/**	 * Set File object.	 */	public void setProperty(final String key, final File val) {		setProperty(key, val.getAbsolutePath());	}	/**	 * Set DateFormat object.	 */	public void setProperty(final String key, final SimpleDateFormat val) {		setProperty(key, val.toPattern());	}	/**	 * Set TimeZone object.	 */	public void setProperty(final String key, final TimeZone val) {		setProperty(key, val.getID());	}	/**	 * Set Date object.	 */	public void setProperty(final String key, final Date val,			final DateFormat fmt) {		setProperty(key, fmt.format(val));	}	/**	 * Set Class object.	 */	public void setProperty(final String key, final Class
     val) {		setProperty(key, val.getName());	}}