java使用Properties类读取配置文件信息

java中使用Properties类可以方便的读取配置信息。首先需要创建一个Properties类的实例，然后使用load方法在入FileInputStream实例指向的配置文件。

假定我们要读取的配置文件内容如下：

# System configuration
# Comments will automatically be excluded by the program.

parameter1=value1
parameter2=value2

代码：

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Properties;

/**
* Main.java
*
* @author outofmemory.cn
*/

public class Main {

Properties config;

/**
* Loads configuration parameters from a textfile and print them out.
*/
public void loadConfigFile() {

//Load configuration file
String filename = "conf/systemconfig.txt";
config = new Properties();

try {

config.load(new FileInputStream(filename));

} catch (FileNotFoundException ex) {
ex.printStackTrace();
return;
} catch (IOException ex) {
ex.printStackTrace();
return;
}

//Print out the configuration parameters
Enumeration en = config.keys();

System.out.println("********** System configuration **********");
while (en.hasMoreElements()) {

String key = (String) en.nextElement();
System.out.println(key + " => " + config.get(key));

}
}
/**
* Starts the program
*
* @param args the command line arguments
*/
public static void main(String[] args) {
new Main().loadConfigFile();
}
}

下面是输出：

********** System configuration **********
parameter2 => value2
parameter1 => value1