用J2SE API读取Properties文件六种方法

最新推荐文章于 2021-02-26 17:46:06 发布

原创最新推荐文章于 2021-02-26 17:46:06 发布 · 432 阅读

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文章标签：

#properties #j2se #api #classloader #string #null

本文介绍并演示了在Java中加载属性文件的六种常见方法，包括使用`Properties`类、`ResourceBundle`类及其子类等，并提供了一个完整的示例程序进行验证。

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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);

　　完整的示例，可以参考附件文件

　　如何上传文件，谁知道请告诉以下。只好把source都贴上来了

　　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