这些我都试了,怎么都不行,这是我测试的代码 import java.sql.*; public class jdbc{ //定义驱动程序的名称 public static final String drivername="oracle.jdbc.driver.OracleDriver"; public static final String URL="jdbc:oracle:thin:@localhost:1521:orcl"; public static final String user="scott"; public static final String password="aaa"; public static void main(String args[]){ String query="select ename,sal from scott.emp where deptno=20"; Connection conn=null; Statement st=null; ResultSet rs=null; try{ //加载驱动器 Class.forName(drivername); //建立连接 conn=DriverManager.getConnection(URL,user,password); //创建statement对象 st=conn.createStatement(); // rs=st.executeQuery(query); while(rs.next()) { System.out.println(rs.getString("ename")+"as"+rs.getString("sal")); } rs.close(); st.close(); conn.close(); } catch(Exception e){ System.out.println("this is error"); } }
}
除了"this is error" 还能报什么错误,这样的调试神仙也没有办法.
catch(Exception e){ System.out.println("this is error"); } 这个不好,数据库连接可能出现异常的点非常多,但就简单的输出"this is error",怎么确定问题?问题都不知道,怎么解决? System.out.println(e); 或者 e.printStackTrace(System.out);
驱动类:"oracle.jdbc.driver.OracleDriver"
Connection connection = null; try {
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException e1) {
System.out.println("数据库驱动类没找到");
}
try {
// 建立连接
String serverName = "xxx.xxx.xxx.xxx"; // or 本机 "localhost"
String portNumber = "1521";
String sid = "database";
String url = "jdbc:oracle:thin:@" + serverName + ":" + portNumber + ":" + sid;
String username = "name";
String password = "password";
connection = DriverManager.getConnection(url, username, password);
System.out.println("数据库连接成功!");
} catch (SQLException e) {
System.out.println("执行SQL语句异常!");
e.printStackTrace();
}
return connection;
}
import java.sql.*;
public class jdbc{
//定义驱动程序的名称
public static final String drivername="oracle.jdbc.driver.OracleDriver";
public static final String URL="jdbc:oracle:thin:@localhost:1521:orcl";
public static final String user="scott";
public static final String password="aaa";
public static void main(String args[]){
String query="select ename,sal from scott.emp where deptno=20";
Connection conn=null;
Statement st=null;
ResultSet rs=null;
try{
//加载驱动器
Class.forName(drivername);
//建立连接
conn=DriverManager.getConnection(URL,user,password);
//创建statement对象
st=conn.createStatement();
//
rs=st.executeQuery(query);
while(rs.next())
{
System.out.println(rs.getString("ename")+"as"+rs.getString("sal"));
}
rs.close();
st.close();
conn.close();
}
catch(Exception e){
System.out.println("this is error");
}
}
}
除了"this is error" 还能报什么错误,这样的调试神仙也没有办法.
System.out.println("this is error");
} 这个不好,数据库连接可能出现异常的点非常多,但就简单的输出"this is error",怎么确定问题?问题都不知道,怎么解决?
System.out.println(e);
或者 e.printStackTrace(System.out);