解决方案：
我添加了这段代码
Class.forName("com.mysql.jdbc.Driver");
兄弟
Connection con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root");
谢谢大家回复我的问题
=====================
我有问题，我尝试使用 servlet 将数据插入 mysql db，但我无法访问 MySQL
- 数据库名称：test
- 表名：测试
- 我已经在项目库中添加了 jdbc 连接器
- 我正在使用 JDK 1.7、NetBeans 7.3、MySQL 5.6、Tomcat 7.0、Connector/J 5.1.24
1-这是 sign_up.jsp 页面中的“表单操作”：
<form action="RegisterUser" method="post">
<td><input type="submit" value="Submit"></td>
</form>
2-这是 RegisterUser.java servlet：
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.mysql.jdbc.Driver;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;
@WebServlet(urlPatterns = {"/RegisterUser"})
public class RegisterUser extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException, SQLException {
try{
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/test", "root", "root");
Statement s = (Statement) con.createStatement();
String name = "Hassan3";
int phone = 123456;
String insert = "INSERT INTO test VALUES ('\" + name + \"', \" + phone + \")";
s.executeUpdate(insert);
s.close();
con.close();
}catch(Exception e){
throw new SecurityException("Class not found " + e.toString());
}
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {
processRequest(request, response);
} catch (SQLException ex) {
Logger.getLogger(RegisterUser.class.getName()).log(Level.SEVERE, null, ex);
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {
processRequest(request, response);
} catch (SQLException ex) {
Logger.getLogger(RegisterUser.class.getName()).log(Level.SEVERE, null, ex);
}
}
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
3-异常结果：
HTTP Status 500 - Class not found java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/test
type Exception report
message Class not found java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/test
description The server encountered an internal error that prevented it from fulfilling this request.
exception
java.lang.SecurityException: Class not found java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/test
RegisterUser.processRequest(RegisterUser.java:66)
RegisterUser.doPost(RegisterUser.java:173)
javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.39 logs.
4-但是当我使用相同的代码但在“没有 servlet 或 web 应用程序”的 java 文件中它工作正常：
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Test {
public static void main(String[] args){
try{
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/test", "root", "root");
Statement s = (Statement) con.createStatement();
String name = "Hassan4";
int phone = 8985895;
String insert = "INSERT INTO test VALUES ('" + name + "', " + phone + ")";
s.executeUpdate(insert);
s.close();
con.close();
System.out.println("done");
}catch(Exception e){
throw new SecurityException("Class not found " + e.toString());
}
}
}
那么servlet有什么问题？为什么代码适用于 java 应用程序。但它不适用于网络应用程序。？
