加载配置文件的方式（java[Properties,InputStream]与apache-commons-configuration组件）

llcong

一 使用原生方式读取配置文件
1 文件系统加载

InputStream in = new FileInputStream("config.properties");
Properties p = new Properties();
p.load(in);


2 类加载方式
A 与类同级目录

InputStream in = Main.class.getResourceAsStream("config.properties");
B 在类的下一级目录

InputStream in =
Main.class.getResourceAsStream("resource/config.properties");

C 指定加载资源配置文件的classes相对路径

InputStream in =
Main.class.getResourceAsStream("/test/resource/config.properties");

注意事项：如上以/开头的是指从根目录开始加载。
D 使用类加载器的方式
InputStream in = Main.class.getClassLoader().
getResourceAsStream("test/resource/config.properties");
E 资源配置文件在classes下

InputStream in =
Main.class.getClassLoader().getResourceAsStream("config.properties");


二 使用apache提供的功能组件
它使用了大量的apache-commons其它组件，很麻烦
参照网上相关资料
1 读取properties文件的方式
示例代码

import java.util.List;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
public class PropertiesConfigurationDemo {
public static void main(String[] args) throws ConfigurationException {
Configuration config = new PropertiesConfiguration(PropertiesConfigurationDemo.class.getResource("system-config.properties"));
String ip = config.getString("ip");      
String[] colors = config.getStringArray("colors.pie");
for (int i = 0; i < colors.length; i++) {
System.out.println(colors);
}
List<?> colorList = config.getList("colors.pie");
for (int i = 0; i < colorList.size(); i++) {
System.out.println(colorList.get(i));
}
}
}

配置文件代码：
ip=10.10.1.1
colors.pie = #FF0000, #00FF00, #0000FF

2 读取XML文件的方式

import java.util.List;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.XMLConfiguration;
public class XMLConfigurationDemo {
public static void main(String[] args) throws ConfigurationException {
Configuration config = new XMLConfiguration(XMLConfigurationDemo.class
.getResource("system-config.xml"));
String ip = config.getString("ip");
String account = config.getString("account");
String password = config.getString("password");
List<?> roles = config.getList("roles.role");
System.out.println("IP: " + ip);
System.out.println("Account: " + account);
System.out.println("Password: " + password);        
for (int i = 0; i < roles.size(); i++) {
System.out.println("Role: " + roles.get(i));
}      
}
}

Xml文件代码：

<config>
<ip>10.10.1.1</ip>
<account>jini</account>
<password>jakarta99</password>
<roles>
<role>admin</role>
<role>manager</role>
<role>user</role>
</roles>
</config>


示例2

import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.XMLConfiguration;
public class XmlConfigurationExample {
public static void main(String[] args) throws Exception,
ConfigurationException {
String resource = "main/global.xml";
Configuration config = new XMLConfiguration(resource);
// 只有new一个XMLConfiguration的实例就可以了.
List<?> startCriteria = config.getList("start-criteria.criteria");
for (int i = 0; i < startCriteria.size(); i++) {
System.out.println("Role: " + startCriteria.get(i));
}
int horsepower = config.getInt("horsepower");
System.out.println(horsepower);
}
}

global.xml文件代码

<?xml version="1.0" encoding="ISO-8859-1" ?>
<engine-config>
<start-criteria>
<criteria>
Temperature Above -10 Celsius
</criteria>
<criteria>
Fuel tank is not empty
</criteria>
</start-criteria>
<volume>4 Liters</volume>
<horsepower>42</horsepower>
</engine-config>


示例3：混合读取二种文件

import java.util.List;
import org.apache.commons.configuration.CompositeConfiguration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.commons.configuration.XMLConfiguration;
public class Test {
public static void main(String[] args) throws ConfigurationException {
CompositeConfiguration config = new CompositeConfiguration();
config.addConfiguration(new PropertiesConfiguration(
"main/global.properties"));
config.addConfiguration(new XMLConfiguration("main/global.xml"));
List<?> startCriteria = config.getList("start-criteria.criteria");
int horsepower = config.getInt("horsepower");
for (int i = 0; i < startCriteria.size(); i++) {
System.out.println("Role: " + startCriteria.get(i));
}
System.out.println(horsepower);
System.out.println("Speed: " + config.getFloat("speed"));
System.out.println("Names: " + config.getString("name"));
}
}

Xml如上所示，global.properties文件如下：
speed=50
name=Default User

示例4

import java.net.URL;
import java.util.List;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.ConfigurationFactory;
public class PropertiesXmlConfigurationExample {
public static void main(String[] args) throws Exception {
ConfigurationFactory factory = new ConfigurationFactory();
URL configURL = PropertiesXmlConfigurationExample.class.getResource("additional-xml-configuration.xml");
factory.setConfigurationURL(configURL);
Configuration config = factory.getConfiguration();
List<?> startCriteria = config.getList("start-criteria.criteria");
for (int i = 0; i < startCriteria.size(); i++) {
System.out.println("Role: " + startCriteria.get(i));
}
int horsepower = config.getInt("horsepower");
System.out.println("Horsepower: " + horsepower);
System.out.println("Speed: " + config.getFloat("speed"));
System.out.println("Names: " + config.getString("name"));
}
}


additional-xml-configuration.xml文件内容：

<?xml version="1.0" encoding="ISO-8859-1" ?>
<configuration>
<properties fileName="global.properties"/>
<xml fileName="global.xml"/>
</configuration>


相关API说明：
# PropertiesConfiguration 从一个 property 文件中加载配置 .
# XMLConfiguration 从 XML 文件中加载配置信息 .
# XMLPropertyListConfiguration 也可以读取 XML 被 Mac OSX 使用变量 .
# JNDIConfiguration 利用 jndi 树的一个键值，可以返回一个值，这个值来作为配置信息
# BaseConfiguration 访问内存中的一个配置对象 .
# HierarchicalConfiguration 一个在内存中的配置对象，这个对象可以处理复杂的数据结构 .
# SystemConfiguration 一个利用系统属性的配置信息
# ConfigurationConverter 把 java.util.Properties 或者 org.apache.collections.commons.ExtendedProperties 转化为一个 Configuration 对象
参考资料：
Jakarta-Common-Configuration使用笔记
http://blog.csdn.net/kunshan_shenbin/archive/2008/01/24/2062542.as
common-configuration读取xml,properties文件
http://javamy.iteye.com/blog/252619
使用apache common configuration读取配置文件或修改配置文件
http://www.suneca.com/article.asp?id=9
附件说明：
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