使用J2SE API读取Properties文件的六种方法

使用J2SE API读取Properties文件的六种方法

1。使用java.util.Properties类的load()方法
示例：

InputStream in = lnew BufferedInputStream(new FileInputStream(name));

Properties p = new Properties();

p.load(in);

2。使用java.util.ResourceBundle类的getBundle()方法
示例：

ResourceBundle rb = ResourceBundle.getBundle(name, Locale.getDefault());

3。使用java.util.PropertyResourceBundle类的构造函数
示例：

InputStream in = new BufferedInputStream(new FileInputStream(name));

ResourceBundle rb = new PropertyResourceBundle(in);

4。使用class变量的getResourceAsStream()方法
示例：

InputStream in = JProperties.class.getResourceAsStream(name);

Properties p = new Properties();

p.load(in);

5。使用class.getClassLoader()所得到的java.lang.ClassLoader的getResourceAsStream()方法
示例：

InputStream in = JProperties.class.getClassLoader().getResourceAsStream(name);

Properties p = new Properties();

p.load(in);

6。使用java.lang.ClassLoader类的getSystemResourceAsStream()静态方法
示例：

InputStream in = ClassLoader.getSystemResourceAsStream(name);

Properties p = new Properties();

p.load(in);

补充

Servlet中可以使用javax.servlet.ServletContext的getResourceAsStream()方法
示例：

InputStream in = context.getResourceAsStream(path);

Properties p = new Properties();

p.load(in);

完整示例:JProperties.java文件

/**

** This program is free software.

** You may redistribute it and/or modify it under the terms of the GNU

** General Public License as published by the Free Software Foundation.

** Version 2 of the license should be included with this distribution in

** the file LICENSE, as well as License.html. If the license is not

** included with this distribution, you may find a copy at the FSF web

** site at 'www.gnu.org' or 'www.fsf.org', or you may write to the

** Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.

** THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY OF ANY KIND,

** NOT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY. THE AUTHOR

** OF THIS SOFTWARE, ASSUMES _NO_ RESPONSIBILITY FOR ANY

** CONSEQUENCE RESULTING FROM THE USE, MODIFICATION, OR

** REDISTRIBUTION OF THIS SOFTWARE.

**/

package com.kindani;

//import javax.servlet.ServletContext;

import java.util.*;

import java.io.InputStream;

import java.io.IOException;

import java.io.BufferedInputStream;

import java.io.FileInputStream;

/**

* 使用J2SE API?取Properties文件的六?方法

* User: SYNFORM

* Date: 2005/07/12

* Time: 18:40:55

* To change this template use File | Settings | File Templates.

public class JProperties {

public final static int BY_PROPERTIES = 1;

public final static int BY_RESOURCEBUNDLE = 2;

public final static int BY_PROPERTYRESOURCEBUNDLE = 3;

public final static int BY_CLASS = 4;

public final static int BY_CLASSLOADER = 5;

public final static int BY_SYSTEM_CLASSLOADER = 6;

public final static Properties loadProperties(final String name, final int type) throws IOException {

Properties p = new Properties();

InputStream in = null;

if (type == BY_PROPERTIES) {

in = new BufferedInputStream(new FileInputStream(name));

assert (in != null);

p.load(in);

} else if (type == BY_RESOURCEBUNDLE) {

ResourceBundle rb = ResourceBundle.getBundle(name, Locale.getDefault());

assert (rb != null);

p = new ResourceBundleAdapter(rb);

} else if (type == BY_PROPERTYRESOURCEBUNDLE) {

in = new BufferedInputStream(new FileInputStream(name));

assert (in != null);

ResourceBundle rb = new PropertyResourceBundle(in);

p = new ResourceBundleAdapter(rb);

} else if (type == BY_CLASS) {

assert (JProperties.class.equals(new JProperties().getClass()));

in = JProperties.class.getResourceAsStream(name);

assert (in != null);

p.load(in);

// return new JProperties().getClass().getResourceAsStream(name);

} else if (type == BY_CLASSLOADER) {

assert (JProperties.class.getClassLoader().equals(new JProperties().getClass().getClassLoader()));

in = JProperties.class.getClassLoader().getResourceAsStream(name);

assert (in != null);

p.load(in);

// return new JProperties().getClass().getClassLoader().getResourceAsStream(name);

} else if (type == BY_SYSTEM_CLASSLOADER) {

in = ClassLoader.getSystemResourceAsStream(name);

assert (in != null);

p.load(in);

}

if (in != null) {

in.close();

}

return p;

}

// ---------------------------------------------- servlet used

public static Properties loadProperties(ServletContext context, String path) throws IOException {

assert (context != null);

InputStream in = context.getResourceAsStream(path);

assert (in != null);

Properties p = new Properties();

p.load(in);

in.close();

return p;

}

// ---------------------------------------------- support class

/**

* ResourceBundle Adapter class.

public static class ResourceBundleAdapter extends Properties {

public ResourceBundleAdapter(ResourceBundle rb) {

assert (rb instanceof java.util.PropertyResourceBundle);

this.rb = rb;

java.util.Enumeration e = rb.getKeys();

while (e.hasMoreElements()) {

Object o = e.nextElement();

this.put(o, rb.getObject((String) o));

}

private ResourceBundle rb = null;

public ResourceBundle getBundle(String baseName) {

return ResourceBundle.getBundle(baseName);

}

public ResourceBundle getBundle(String baseName, Locale locale) {

return ResourceBundle.getBundle(baseName, locale);

}

public ResourceBundle getBundle(String baseName, Locale locale, ClassLoader loader) {

return ResourceBundle.getBundle(baseName, locale, loader);

}

public Enumeration getKeys() {

return rb.getKeys();

}

public Locale getLocale() {

return rb.getLocale();

}

public Object getObject(String key) {

return rb.getObject(key);

}

public String getString(String key) {

return rb.getString(key);

}

public String[] getStringArray(String key) {

return rb.getStringArray(key);

}

protected Object handleGetObject(String key) {

return ((PropertyResourceBundle) rb).handleGetObject(key);

}

JPropertiesTest.java文件