使用J2SE API读取Properties文件的六大方法（综合篇）

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:

JProperties.java文件


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文件的六种方法
* 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<String> 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


package com.kindani.test;

import junit.framework.*;
import com.kindani.JProperties;

//import javax.servlet.ServletContext;
import java.util.Properties;

public class JPropertiesTest extends TestCase {
    JProperties jProperties;
    String key = "helloworld.title";
    String value = "Hello World!";

    public void testLoadProperties() throws Exception {
        String name = null;
        Properties p = new Properties();

        name = "C:\\IDEAP\\Properties4Methods\\src\\com\\
kindani\\test\\LocalStrings.properties";
        p = JProperties.loadProperties(name, JProperties.BY_PROPERTIES);
        assertEquals(value, p.getProperty(key));

        name = "com.kindani.test.LocalStrings";
        p = JProperties.loadProperties(name,JProperties.BY_RESOURCEBUNDLE);
        assertEquals(value, p.getProperty(key));
        assertEquals(value,((JProperties.ResourceBundleAdapter)p).getString(key));

        name = "C:\\IDEAP\\Properties4Methods\\src\\com\\
kindani\\test\\LocalStrings.properties";
        p = JProperties.loadProperties(name, JProperties.BY_PROPERTYRESOURCEBUNDLE);
        assertEquals(value, p.getProperty(key));
        assertEquals(value,((JProperties.ResourceBundleAdapter)p).getString(key));

        name = "\\com\\kindani\\test\\LocalStrings.properties";
        p = JProperties.loadProperties(name, JProperties.BY_SYSTEM_CLASSLOADER);
        assertEquals(value, p.getProperty(key));

        name = "\\com\\kindani\\test\\LocalStrings.properties";
        p = JProperties.loadProperties(name, JProperties.BY_CLASSLOADER);
        assertEquals(value, p.getProperty(key));

        name = "test\\LocalStrings.properties";
        p = JProperties.loadProperties(name, JProperties.BY_CLASS);
        assertEquals(value, p.getProperty(key));
    }

/*
    public void testLoadProperties2() throws Exception {
        ServletContext context = null;
        String path = null;
        Properties p = null;
        path = "/WEB-INF/classes/LocalStrings.properties";
        p = JProperties.loadProperties(context, path);
        assertEquals(value, p.getProperty(key));
    }
*/
}
properties文件与JPropertiesTest.java文件相同的目录下

LocalStrings.properties文件


# $Id: LocalStrings.properties,v 1.1 2000/08/17 00:57:52 horwat Exp $

# Default localized resources for example servlets
# This locale is en_US

helloworld.title=Hello World!

requestinfo.title=Request Information Example
requestinfo.label.method=Method:
requestinfo.label.requesturi=Request URI:
requestinfo.label.protocol=Protocol:
requestinfo.label.pathinfo=Path Info:
requestinfo.label.remoteaddr=Remote Address:

requestheader.title=Request Header Example

requestparams.title=Request Parameters Example
requestparams.params-in-req=Parameters in this request:
requestparams.no-params=No Parameters, Please enter some
requestparams.firstname=First Name:
requestparams.lastname=Last Name:

cookies.title=Cookies Example
cookies.cookies=Your browser is sending the following cookies:
cookies.no-cookies=Your browser isn't sending any cookies
cookies.make-cookie=Create a cookie to send to your browser
cookies.name=Name:
cookies.value=Value:
cookies.set=You just sent the following cookie to your browser:

sessions.title=Sessions Example
sessions.id=Session ID:
sessions.created=Created:
sessions.lastaccessed=Last Accessed:
sessions.data=The following data is in your session:
sessions.adddata=Add data to your session
sessions.dataname=Name of Session Attribute:
sessions.datavalue=Value of Session Attribute: