出现这个异常原因可能很多：
1.编码问题
2.没有加载类驱动：换一种数据库的连接方式，就忘了这个：Class.forName(driverclass);
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties; public class JdbcUtil {
private static String driverclass;
private static String url;
private static String user;
private static String password;
static{
try{
ClassLoader cl=JdbcUtil.class.getClassLoader(); InputStream in=cl.getResourceAsStream("dbbcfg.properties");
Properties props=new Properties();
props.load(in); driverclass=props.getProperty("driverClass");
url=props.getProperty("url");
user=props.getProperty("user");
password=props.getProperty("password"); in.close();
}catch (Exception e){
e.printStackTrace();
}
try {
Class.forName(driverclass);
}catch (ClassNotFoundException e){
e.printStackTrace();
}
}
public static Connection getConnection(){
try {
Connection conn = DriverManager.getConnection(url,user,password);
return conn;
} catch (Exception e) {
throw new RuntimeException("链接数据库的url或用户名密码错误,请检查您的配置文件");
}
}
public static void release(ResultSet rs,Statement stmt,Connection conn){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs = null;
}
if(stmt!=null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
public static void main(String[] args){
System.out.println("Test connection");
try{
Connection conn=JdbcUtil.getConnection();
System.out.println(conn); }catch (Exception e){
e.printStackTrace();
} }
}