老师, 请问一下, 我按照视频中的方法加载"db.properties"文件到输入流, 但是输入流是null.. 请看:
DBUtil.JAVA文件截图:

代码:
package com.yuanzhao.dbutil;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class DBUtil {
private static String url;
private static String user;
private static String password;
static {
try {
Properties prop = new Properties();
// 创建文件输入流
InputStream is = DBUtil.class.getClassLoader().getResourceAsStream("db.properties");
//测试输出
System.out.println(is);
// 加载配置文件
prop.load(is);
url = prop.getProperty("jdbc.url").trim();
user = prop.getProperty("jdbc.username").trim();
password = prop.getProperty("jdbc.password").trim();
} catch (IOException e) {
e.printStackTrace();
}
}
public static Connection getConn() {
Connection conn = null;
try {
conn = DriverManager.getConnection(url, user, password);
} catch (SQLException e) {
System.out.println("DBUtil.getConn(连接创建失败, 请检查[url]:" + url + ", [user]:" + user + ", [password]:" + password + ")");
}
return conn;
}
public static Statement getStatement(Connection conn) {
Statement statement = null;
try {
statement = conn.createStatement();
} catch (SQLException e) {
e.printStackTrace();
}
return statement;
}
public static PreparedStatement getStatement(Connection conn, String sql) {
PreparedStatement preparedStatement = null;
try {
preparedStatement = conn.prepareStatement(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return preparedStatement;
}
public static void bindParam(PreparedStatement preparedStatement, Object... params) {
try {
for (int i = 0; i < params.length; i++) {
preparedStatement.setObject((i + 1), params[i]);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(ResultSet resultSet, Statement statement, Connection conn) {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (statement != null) {
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
源代码打包:
MyPro0305.zip