import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class QueryTest
{
private Connection con;
public static void main(String [] atgs)
{
QueryTest test = new QueryTest();
Connection con = test.getConnection();
String sql = "select * from Student";
test.getStudent(con, sql);
}
public void getStudent(Connection con, String sql)
{
try
{
Statement st = con.createStatement(); //申请会话
ResultSet rs = st.executeQuery(sql); //获得查询记录集
while( rs.next() )
{
String name = rs.getString( "姓名" );
String number = rs.getString( "学号" );
String sex = rs.getString( "性别" );
Date date = rs.getDate( "生日" );
String spe = rs.getString( "专业" );
String address = rs.getString( "籍贯" );
System.out.println( "\n姓名: " + name + "\t学号" + number + "\t性别" + sex
+ "\t生日" + date + "\t专业" + spe + "\t籍贯" + address );
}
st.close();
con.close();
}
catch( SQLException e )
{
e.printStackTrace();
}
}
public Connection getConnection()
{
String url = "jdbc:sqlserver://localhost:1433; DatabaseName= Student";
String username = "sa";
String password = "";
try
{
//登陆jdbc驱动程序
Class.forName( "com.microsoft.jdbc.sqlserver.SQLServerDriver");
con = DriverManager.getConnection(url, username, password);
}
catch( SQLException e )
{
e.printStackTrace();
}
catch( ClassNotFoundException ex )
{
ex.printStackTrace();
System.out.println( "报错 " );
}
return con;
}
}
运行时出现以下问题 请帮忙解决
java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at QueryTest.getConnection(QueryTest.java:57)
at QueryTest.main(QueryTest.java:15)
报错
Exception in thread "main" java.lang.NullPointerException
at QueryTest.getStudent(QueryTest.java:24)
at QueryTest.main(QueryTest.java:17)
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class QueryTest
{
private Connection con;
public static void main(String [] atgs)
{
QueryTest test = new QueryTest();
Connection con = test.getConnection();
String sql = "select * from Student";
test.getStudent(con, sql);
}
public void getStudent(Connection con, String sql)
{
try
{
Statement st = con.createStatement(); //申请会话
ResultSet rs = st.executeQuery(sql); //获得查询记录集
while( rs.next() )
{
String name = rs.getString( "姓名" );
String number = rs.getString( "学号" );
String sex = rs.getString( "性别" );
Date date = rs.getDate( "生日" );
String spe = rs.getString( "专业" );
String address = rs.getString( "籍贯" );
System.out.println( "\n姓名: " + name + "\t学号" + number + "\t性别" + sex
+ "\t生日" + date + "\t专业" + spe + "\t籍贯" + address );
}
st.close();
con.close();
}
catch( SQLException e )
{
e.printStackTrace();
}
}
public Connection getConnection()
{
String url = "jdbc:sqlserver://localhost:1433; DatabaseName= Student";
String username = "sa";
String password = "";
try
{
//登陆jdbc驱动程序
Class.forName( "com.microsoft.jdbc.sqlserver.SQLServerDriver");
con = DriverManager.getConnection(url, username, password);
}
catch( SQLException e )
{
e.printStackTrace();
}
catch( ClassNotFoundException ex )
{
ex.printStackTrace();
System.out.println( "报错 " );
}
return con;
}
}
运行时出现以下问题 请帮忙解决
java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at QueryTest.getConnection(QueryTest.java:57)
at QueryTest.main(QueryTest.java:15)
报错
Exception in thread "main" java.lang.NullPointerException
at QueryTest.getStudent(QueryTest.java:24)
at QueryTest.main(QueryTest.java:17)
解决方案 »
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