mport java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
/**
* JDBC工具类
*/
public class JDBCUtil {
private static String driver = "com.mysql.jbdc.Driver";
private static String jdbcUrl = "jdbc:mysql://localhost:3306/bjsxt?useUnicode=true&characterEncoding=utf-8";
private static String username = "root";
private static String userpassword = "rsc125979";
static {
// 注册驱动
try {
Class.forName(driver);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
// 获取Connection对象
public static Connection getConnection(){
// 创建连接
Connection conn =null;
try {
conn = DriverManager.getConnection(jdbcUrl,username,userpassword);
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
// 关闭Statement
public static void closeStatement(Statement state){
if(state != null){
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
// 关闭Connection
public static void closeConnection(Connection conn){
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
// 关闭资源 将关闭Connection和Statement方法放到一起
public static void closeResource(Statement state,Connection conn){
closeStatement(state);
closeConnection(conn);
}
}
public class JDBXTest
// 更新departments表中department_id为6的数据
public void updateDepartments(String department_name,int location_id,int department_id){
Connection conn = null;
Statement state = null;
try{
conn = JDBCUtil.getConnection();
state = conn.createStatement();
// sql语句
String sql = "update departments d set d.department_name = '"+department_name+"',d.location_id="+location_id+" where d.department_id = "+department_id+" ";
// 执行sql语句
int flag = state.executeUpdate(sql);
System.out.println(flag);
}catch(Exception e) {
e.printStackTrace();
} finally{
JDBCUtil.closeResource(state,conn);
}
}
public static void main(String[] args) {
JDBXTest test = new JDBXTest();
test.updateDepartments("IT",6,11);
}
}
语句执行成功了，但是为什么会报异常呀，没有使用工具类时更新数据没有报异常
报错的位置分别是
JDBCUtil中的
Class.forName(driver);
JDBCTest中的
conn = JDBCUtil.getConnection();
和
test.updateDepartments("IT",6,11);
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