java 静态代码块加载配置文件信息 方法2

文件结构:



db.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306?characterEncoding=utf8
username=root
password=123456

Main.java
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class Main {

private static String driver;
private static String url;
private static String username;
private static String password;
static
{
try {
//获取当前类加载器
ClassLoader classLoader=Main.class.getClassLoader();
//通过当前累加载器方法获得 文件db.properties的一个输入流
InputStream is=classLoader.getResourceAsStream("db.properties");
//创建一个Properties 对象
Properties properties=new Properties();
//加载输入流
properties.load(is);

driver=properties.getProperty("driver");
url=properties.getProperty("url");
username=properties.getProperty("username");
password=properties.getProperty("password");

}
catch (IOException e) {
e.printStackTrace();
}

}
public static void main(String[] args){
System.out.println(driver);
System.out.println(url);
System.out.println(username);
System.out.println(password);
}
}


运行结果: