import java.sql.*;
public class osconn
{public static final String sDBDriver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
public static final String sConnStr="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=ee";
public static final String user="sa";
public static final String password="";
Connection connect=null;
ResultSet rs=null;
Statement stmt=null;public osconn()
{
try
{
Class.forName(sDBDriver);
}
catch (java.lang.ClassNotFoundException e)
{
System.err.println(e.getMessage());
}
}
public ResultSet executeQuery(String sql)
{
try
{
connect=DriverManager.getConnection(sConnStr,user,password);
Statement stmt=connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=stmt.executeQuery(sql);
System.out.println("连接数据库成功");
return rs;
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
System.out.println("在这里发生异常啦");
return null;
}
}
public int executeUpdate(String sql)
{
int result=0;
try
{
connect=DriverManager.getConnection(sConnStr,user,password);
Statement stmt=connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
result=stmt.executeUpdate(sql);
stmt.close();
connect.close();
return result;
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
return result;
}
}public void closeConn(String sql)
{
try
{
stmt.close();
connect.close();
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
}
}public static void main(String[] args)
{
osconn conn=new osconn();
conn.executeQuery("select * from try");
conn.closeConn();
}}
编译的时候出现以下提示:---------- javac ----------
D:\try\osconn.java:78: 无法将 osconn 中的 closeConn(java.lang.String) 应用于 ()
conn.closeConn();
^
1 错误输出完成 (耗时: 1 秒) - 正常终止
public class osconn
{public static final String sDBDriver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
public static final String sConnStr="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=ee";
public static final String user="sa";
public static final String password="";
Connection connect=null;
ResultSet rs=null;
Statement stmt=null;public osconn()
{
try
{
Class.forName(sDBDriver);
}
catch (java.lang.ClassNotFoundException e)
{
System.err.println(e.getMessage());
}
}
public ResultSet executeQuery(String sql)
{
try
{
connect=DriverManager.getConnection(sConnStr,user,password);
Statement stmt=connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=stmt.executeQuery(sql);
System.out.println("连接数据库成功");
return rs;
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
System.out.println("在这里发生异常啦");
return null;
}
}
public int executeUpdate(String sql)
{
int result=0;
try
{
connect=DriverManager.getConnection(sConnStr,user,password);
Statement stmt=connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
result=stmt.executeUpdate(sql);
stmt.close();
connect.close();
return result;
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
return result;
}
}public void closeConn(String sql)
{
try
{
stmt.close();
connect.close();
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
}
}public static void main(String[] args)
{
osconn conn=new osconn();
conn.executeQuery("select * from try");
conn.closeConn();
}}
编译的时候出现以下提示:---------- javac ----------
D:\try\osconn.java:78: 无法将 osconn 中的 closeConn(java.lang.String) 应用于 ()
conn.closeConn();
^
1 错误输出完成 (耗时: 1 秒) - 正常终止
改为
public void closeConn()你这个关闭函数根本不用输入sql参数。你调用的时候用的是无参数的的closeConn函数,而你的程序没有定义public void closeConn()这样的函数
import java.sql.*;
public class osconn
{public static final String sDBDriver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
public static final String sConnStr="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=ee";
public static final String user="sa";
public static final String password="";
private static Connection connect=null;
private static ResultSet rs=null;
private static Statement stmt=null;public osconn()
{
try
{
Class.forName(sDBDriver);
}
catch (java.lang.ClassNotFoundException e)
{
System.err.println(e.getMessage());
}
}
public ResultSet executeQuery(String sql)
{
try
{
connect=DriverManager.getConnection(sConnStr,user,password);
stmt=connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=stmt.executeQuery(sql);
System.out.println("连接数据库成功");
return rs;
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
System.out.println("在这里发生异常啦");
return rs;
}
}
public int executeUpdate(String sql)
{
int result=0;
try
{
connect=DriverManager.getConnection(sConnStr,user,password);
Statement stmt=connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
result=stmt.executeUpdate(sql);
stmt.close();
connect.close();
return result;
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
return result;
}
}/*public void closeStmt(){
try{
stmt.close();
System.out.println("关闭stmt");
}catch(SQLException e){
e.printStackTrace();
}
}
public void closeConn(){try {
connect.close();
System.out.println("关闭connect");
} catch (SQLException e) {
e.printStackTrace();
}
}*/
public void closeConn()
{
try
{
stmt.close();
System.err.println("关闭stmt");
connect.close();
System.err.println("关闭connect");
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void main(String[] args)
{
try
{
osconn conn=new osconn();
rs=conn.executeQuery("select * from try");
while(rs.next())
{
System.out.print(rs.getString(1));
System.out.println(rs.getString(2)); }
conn.closeConn();
}
catch (SQLException e)
{
e.printStackTrace();
}
}}