Java 加载配置文件的方式

一使用原生方式读取配置文件

1 文件系统加载

Java代码

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

Java代码

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

B 在类的下一级目录

Java代码

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

Java代码

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

Java代码

InputStream in = Main.class.getClassLoader().

getResourceAsStream("test/resource/config.properties");

E 资源配置文件在classes下

Java代码

InputStream in =

Main.class.getClassLoader().getResourceAsStream("config.properties");

二使用apache提供的功能组件

参照网上相关资料

1 读取properties文件的方式

示例代码

Java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[i]);

}

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

Java代码

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：

Xml代码

<password>jakarta99</password>

<roles>

<role>admin</role>

<role>manager</role>

</roles>

</config>

示例2

Java代码

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代码

<?xml version="1.0" encoding="ISO-8859-1" ?>

<engine-config>

<start-criteria>

Temperature Above -10 Celsius

</criteria>

Fuel tank is not empty

</criteria>

</start-criteria>

<volume>4 Liters</volume>

</engine-config>

示例3：混合读取二种文件

Java代码

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

Java代码

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代码

<?xml version="1.0" encoding="ISO-8859-1" ?>

</configuration>