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);

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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;
}

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读取properties文件的另一个例子：

配置文件的作用真是非常方便. 先放上配置文件. <CmdRelation.properties> 2222222=abc
1010001=efg
1010002=aaa
1010003=bbbb
現在是java文件. import java.io.*;
import java.util.*; public class TestProperties
{
public static void main(String dd[])throws Exception{
Properties p = new Properties();
FileInputStream ferr=new FileInputStream("CmdRelation.properties");
       try{
        p.load(ferr);
        ferr.close();
        Set s = p.keySet();
        System.out.println(s.toString());
        Iterator it = s.iterator();
        while(it.hasNext()){
         String id = (String)it.next();
         System.out.println("------key------"+id);
         String value = p.getProperty(id);
         System.out.println("------value:---"+value);
        }
        System.out.println(p.toString());  
       }catch(Exception e){
        e.printStackTrace();
       }
}
}          下麵是運行結果: ---------- java ----------
[2222222, 1010003, 1010002, 1010001]
------key------2222222
------value:---abc
------key------1010003
------value:---bbbb
------key------1010002
------value:---aaa
------key------1010001
------value:---efg
{2222222=abc, 1010003=bbbb, 1010002=aaa, 1010001=efg} 输出完成 (耗时 0 秒) - 正常终止        這樣就把配置文件的信息都讀取齣來暸. 讀取的信息可以封裝成對象作為后續的項目基礎. 是非常方便的東東..

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在项目中使用Properties的示例如下：（将Properties
文件读出，放进Map或者List中）

1、

      Map msgInfoMap = new HashMap();
      List list = new List();
      Properties properties = new Properties();
      int i =0;
      try {
       properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("application.properties"));
       Enumeration      msgIter = properties.keys();
        String msgKey = null;
             while (msgIter.hasMoreElements()) {
                 msgKey = (String) msgIter.nextElement();
                 msgInfoMap.put(msgKey, properties.getProperty(msgKey));
             }
      } catch (IOException e) {
      e.printStackTrace();
      }

2、

      Map msgInfoMap = new HashMap();
      List list = new List();
      Properties properties = new Properties();
      int i =0;

      try {
       properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("application.properties"));
       Enumeration      msgIter = properties.keys();
        String msgKey = null;
             while (msgIter.hasMoreElements()) {
              i = i + 1;
              msgKey = (String) msgIter.nextElement();
              list.add(properties.getProperty(msgKey),i);
             }
      } catch (IOException e) {
      e.printStackTrace();
      }

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补充：

将文件读出后，转成List或者Map对象

   // *************************************************************************************

   Map msgInfoMap = new HashMap();
   List list = new List();
   Properties properties = new Properties();
   int i =0;
//   try {
//    properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("application.properties"));
//    Enumeration   msgIter = properties.keys();
//     String msgKey = null;
//          while (msgIter.hasMoreElements()) {
//              msgKey = (String) msgIter.nextElement();
//              msgInfoMap.put(msgKey, properties.getProperty(msgKey));
//          }
//   } catch (IOException e) {
//   e.printStackTrace();
//   }
   try {
    properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("application.properties"));
    Enumeration   msgIter = properties.keys();
     String msgKey = null;
          while (msgIter.hasMoreElements()) {
           i = i + 1;
           msgKey = (String) msgIter.nextElement();
           list.add(properties.getProperty(msgKey),i);
          }
   } catch (IOException e) {
   e.printStackTrace();
   }
   // *************************************************************************************