package cn.itcast_02;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import org.junit.Test;
//这是获取Collection的工具类
public class JdbcUtils {
public static Connection getConnection() throws IOException, ClassNotFoundException, SQLException {
  // 加载配置文件
   
  InputStream is=JdbcUtils.class.getClassLoader().getResourceAsStream("dbconfig.properties");
//BufferedReader br = new BufferedReader(new FileReader("dbconfig.properties"));
  Properties pro = new Properties();
  pro.load(is);
  // 加载驱动类
  Class.forName(pro.getProperty("driverClassName"));
  // 得到Connection
  return DriverManager.getConnection(pro.getProperty("url"), pro.getProperty("username"),
    pro.getProperty("password"));
}
@Test
public void fun() throws ClassNotFoundException, IOException, SQLException {
  Connection con = JdbcUtils.getConnection();
  System.out.println(con);
}
}

为什么换成红色的语句就不行呢？不都是加载文本文件吗？

package cn.itcast_02;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import org.junit.Test;
//这是获取Collection的工具类
public class JdbcUtils {
public static Connection getConnection() throws IOException, ClassNotFoundException, SQLException {
  // 加载配置文件
   
  InputStream is=JdbcUtils.class.getClassLoader().getResourceAsStream("dbconfig.properties");
//BufferedReader br = new BufferedReader(new FileReader("dbconfig.properties"));
  Properties pro = new Properties();
  pro.load(is);
  // 加载驱动类
  Class.forName(pro.getProperty("driverClassName"));
  // 得到Connection
  return DriverManager.getConnection(pro.getProperty("url"), pro.getProperty("username"),
    pro.getProperty("password"));
}
@Test
public void fun() throws ClassNotFoundException, IOException, SQLException {
  Connection con = JdbcUtils.getConnection();
  System.out.println(con);
}
}

为什么换成红色的语句就不行呢？不都是加载文本文件吗？