import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Properties;

public class ClassLoadDemo {
    public static void main(String[] args) throws Exception {
        //test1();

        test2();//以后開發(fā)中用的更多的是第二種
        
        //test3();
        
    }

    //3.使用相對路徑-相對于當(dāng)前加載資源文件的字節(jié)碼路徑
    private static void test3() throws Exception {
        //此時使用的ClassLoadDemo的字節(jié)碼路徑去尋找db.properties
        Properties pro = new Properties();
        InputStream in = ClassLoadDemo.class.getResourceAsStream("db.properties");
        pro.load(in);
        System.out.println(pro);
    }

    //2.使用相對路徑加載文件-相對于classpath的根路徑(字節(jié)碼輸出目錄)
    private static void test2() throws Exception {
        //此時使用的ClassLoader(類加載器),類加載器默認(rèn)就是從classPath根路徑去尋找文件的
        Properties p1 = new Properties();
        //ClassLoader loader = ClassLoadDemo.class.getClassLoader();
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        InputStream in = loader.getResourceAsStream("dp.properties");
        p1.load(in);
        System.out.println(p1);
    }

    //1.使用絕對路徑加載文件
    private static void test1() throws Exception {
        // TODO Auto-generated method stub
        Properties p = new Properties();
        InputStream in = new FileInputStream(new File("D:/Eclipse-jee/workplace/ClassDemo/db.properties"));
        p.load(in);
        System.out.println(p);
    }
}