問題一:
1 String driver="org.mjt.mm.mysql.Driver";
2 String driver="org.gjt.mm.mysql.Driver";
3 String driver="com.mysql.jdbc.Driver";
1,2,3 三個不同,分別代表什么?問題二:
mysql-connector-java-5.1.7-bin.jar
應該放在哪里?因下面程序是單獨運行。
我放到了tomcat/lib. java/lib。在classpath指向了java/lib中。
===================代碼===================
import java.io.*;
import java.sql.*;
public class testmysql{
public static void main(String[] args){
1 //String driver="org.mjt.mm.mysql.Driver";
2 //String driver="org.gjt.mm.mysql.Driver";
3 String driver="com.mysql.jdbc.Driver";
String url="jdbc:mysql://localhost:3304/mysql";
String username="user";
String pwd="";
try{
Class.forName(driver);
}catch(Exception E){
System.out.println("Loading Driver Error:"+driver);
E.printStackTrace();
}
try {
Connection con=DriverManager.getConnection(url,username,pwd);
Statement stm=con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
String sql="select * from user";
ResultSet rs = stm.executeQuery(sql);
while(rs.next()){
System.out.println(rs.getString(1));
}
System.out.println("sccessfull");
}catch(SQLException ES){
ES.printStackTrace();
} }
}
=========================================================錯誤信息===================================
Loading Driver Error:com.mysql.jdbc.Driver
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at testmysql.main(testmysql.java:15)
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getConnection(DriverManager.java:545)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at testmysql.main(testmysql.java:22)
1 String driver="org.mjt.mm.mysql.Driver";
2 String driver="org.gjt.mm.mysql.Driver";
3 String driver="com.mysql.jdbc.Driver";
1,2,3 三個不同,分別代表什么?問題二:
mysql-connector-java-5.1.7-bin.jar
應該放在哪里?因下面程序是單獨運行。
我放到了tomcat/lib. java/lib。在classpath指向了java/lib中。
===================代碼===================
import java.io.*;
import java.sql.*;
public class testmysql{
public static void main(String[] args){
1 //String driver="org.mjt.mm.mysql.Driver";
2 //String driver="org.gjt.mm.mysql.Driver";
3 String driver="com.mysql.jdbc.Driver";
String url="jdbc:mysql://localhost:3304/mysql";
String username="user";
String pwd="";
try{
Class.forName(driver);
}catch(Exception E){
System.out.println("Loading Driver Error:"+driver);
E.printStackTrace();
}
try {
Connection con=DriverManager.getConnection(url,username,pwd);
Statement stm=con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
String sql="select * from user";
ResultSet rs = stm.executeQuery(sql);
while(rs.next()){
System.out.println(rs.getString(1));
}
System.out.println("sccessfull");
}catch(SQLException ES){
ES.printStackTrace();
} }
}
=========================================================錯誤信息===================================
Loading Driver Error:com.mysql.jdbc.Driver
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at testmysql.main(testmysql.java:15)
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getConnection(DriverManager.java:545)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at testmysql.main(testmysql.java:22)
問題一:
1 String driver="org.mjt.mm.mysql.Driver";
2 String driver="org.gjt.mm.mysql.Driver";
3 String driver="com.mysql.jdbc.Driver";
1,2,3 三個不同,分別代表什么?
都是mysql的driver, 第一个好像没看到过, 现在一般都用第三个。問題二:
mysql-connector-java-5.1.7-bin.jar
應該放在哪里?因下面程序是單獨運行。
我放到了tomcat/lib. java/lib。在classpath指向了java/lib中。
放到tomcat/common/lib下面。