我重新在工程下创建了一个包,包里写了一个类;是为了节省代码量而写的JDBC语句。package com.bbs.DBConnecion;import java.sql.*;public class ConnectionDB {
public static Connection getConnection(){
Connection conn=null;
try {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
try {
conn=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;DatabaseName=bbsDB","fanxiang","12345");
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
public static void closeConnection(Connection DBConnection){
try {
if(DBConnection!=null&&(!DBConnection.isClosed())){
DBConnection.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void closeResultSet(ResultSet rs){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs=null;
}
}
public static void closeStatement(Statement stat){
if(stat!=null){
try {
stat.close();
} catch (SQLException e) {
e.printStackTrace();
}
stat=null;
}
}
public static void PreparedStatement(PreparedStatement parp){
if(parp!=null){
try {
parp.close();
} catch (SQLException e) {
e.printStackTrace();
}
parp=null;
}
}}
在实现接口中实现添加用户这个方法,要调用数据库连接语句,这么不行 就是报错呢??package com.bbs.fx.dao.imple;
import com.bbs.fx.User;
import com.bbs.fx.dao.UserDao;public class UserDaoImpl implements UserDao {
//private User[] users=new User[10];
/**
* 增加用户
*/
public int addUser(User user) {
/*for(int i=0;i<users.length;i++){
if(users[i]==null){
users[i]=user;
users[i].setUId(i);
return 1;
}
}
*/
Connection conn=null;
return 0;
}
public static Connection getConnection(){
Connection conn=null;
try {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
try {
conn=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;DatabaseName=bbsDB","fanxiang","12345");
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
public static void closeConnection(Connection DBConnection){
try {
if(DBConnection!=null&&(!DBConnection.isClosed())){
DBConnection.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void closeResultSet(ResultSet rs){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs=null;
}
}
public static void closeStatement(Statement stat){
if(stat!=null){
try {
stat.close();
} catch (SQLException e) {
e.printStackTrace();
}
stat=null;
}
}
public static void PreparedStatement(PreparedStatement parp){
if(parp!=null){
try {
parp.close();
} catch (SQLException e) {
e.printStackTrace();
}
parp=null;
}
}}
在实现接口中实现添加用户这个方法,要调用数据库连接语句,这么不行 就是报错呢??package com.bbs.fx.dao.imple;
import com.bbs.fx.User;
import com.bbs.fx.dao.UserDao;public class UserDaoImpl implements UserDao {
//private User[] users=new User[10];
/**
* 增加用户
*/
public int addUser(User user) {
/*for(int i=0;i<users.length;i++){
if(users[i]==null){
users[i]=user;
users[i].setUId(i);
return 1;
}
}
*/
Connection conn=null;
return 0;
}
Connection conn=null没有错。
写到conn=ConnectionDB.getConnection();就报错了 写不下去了。指点指点大家。
两个类不在一个包下,需要导包的。import com.bbs.DBConnecion;