class gg 不是这样写的 你可以先写一个数据库连接的类
import java.sql.*;public class DBConnection {
public static Connection getConnection() {
Connection conn = null;
String username = xxxx;
String password = xxxx;
String url = xxxx;
String driver = xxxx; try {
Class.forName(driver);
conn = DriverManager.getConnection(url, username, password);
} catch (SQLException ex) {
ex.printStackTrace();
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
return conn;
}
}
其中xxx的地方就是针对你的数据库的一些信息 包括用户名、密码、驱动、url
import java.sql.*;public class DBConnection {
public static Connection getConnection() {
Connection conn = null;
String username = xxxx;
String password = xxxx;
String url = xxxx;
String driver = xxxx; try {
Class.forName(driver);
conn = DriverManager.getConnection(url, username, password);
} catch (SQLException ex) {
ex.printStackTrace();
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
return conn;
}
}
其中xxx的地方就是针对你的数据库的一些信息 包括用户名、密码、驱动、url
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public abstract class DBOperation
{
public abstract Bean addRecord();
public abstract Bean modifyRecord();
public abstract Bean deleteRecord();
public abstract Bean selectRecord();
}
PreparedStatement pSta;
String Query = "yourcql" //增删改cql
try {
pSta = conn.prepareStatement(Query); pSta.executeUpdate();
} catch (SQLException ex) {
}
PreparedStatement 还有一些挺方便的用法 去查api吧
private Connection conn = null;
protected AbstractDB(){
DBManager.getConnection();
}
protected AbstractDB(Connection conn){
this.conn = conn;
}
public abstract Bean addRecord();
public abstract Bean modifyRecord();
public abstract Bean deleteRecord();
public abstract Bean selectRecord();
protected void closeConnection(){
try{
if(null != conn){
conn.close();
}
}catch(Exception e){
e.printStackTrace();
}
}
}
有MSN吗? 想认识一下你。
password 空 ,数据库 mydb ,永这个abstracte 怎么实现呢
总结一下
public abstract class DBConnection {
public static Connection getConnection() {
Connection conn = null;
String username = "sa";
String password = "";
String url = "jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=pubs";
String driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver"; try {
Class.forName(driver);
conn = DriverManager.getConnection(url, username, password);
} catch (SQLException ex) {
ex.printStackTrace();
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
return conn;
}
}public abstract class DBOperation
{
Connection conn =null ;
public void getConn(){
conn= DBConnection.getConnection();
{ public abstract Bean addRecord();
public abstract Bean modifyRecord();
public abstract Bean deleteRecord();
public abstract Bean selectRecord();
}增删改
public void addRecord() {
PreparedStatement pSta;
String Query = "yourcql" //增删改cql
try {
pSta = conn.prepareStatement(Query); pSta.executeUpdate();
} catch (SQLException ex) {
}
看看EJB的借口设计就明白了.晕,居然叫人家去看EJB..............
public Connection conn=null;
public Statement st=null;
public ResultSet rs=null;
//连接sqlserver
public OpenDB() {
String dburl="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=netoastruts";
String dbuser="sa";
String dbpasswd="sa";
try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
conn=DriverManager.getConnection(dburl,dbuser,dbpasswd);
st=getStatement();
}
catch (Exception ex) {
ex.printStackTrace();
}
}
//连接mysql
public OpenDB(String mysql){
try{
String dburl="jdbc:mysql://127.0.0.1:3306/test";
String dbuser="root";
String dbpasswd="123456";
Class.forName("org.git.mm.mysql.Driver").newInstance();
conn = DriverManager.getConnection(dburl, dbuser, dbpasswd);
st=getStatement();
}catch(Exception e){
e.printStackTrace();
}
} //连接oracle
public OpenDB(int oracle){
String dburl="jdbc:oracle:thin:@localhost:1521:orcl";
String dbuser="scott";
String dbpasswd="tiger";
try {
Class.forName("oracle.jdbc.OracleDriver");
conn=DriverManager.getConnection(dburl,dbuser,dbpasswd);
st=getStatement();
}
catch (Exception ex) {
ex.printStackTrace();
}
} //建立状态通道
public Statement getStatement(){
Statement s=null;
try {
s=conn.createStatement();
}
catch (Exception ex) {
ex.printStackTrace();
}
return s;
} //增、删、改
public boolean doEdit(String sql){
int count=0;
try {
count=st.executeUpdate(sql);
}
catch (Exception ex) {
ex.printStackTrace();
}
finally{
return count>0?true:false;
}
} //查
public ResultSet doQuery(String sql){
try {
rs=st.executeQuery(sql);
}
catch (Exception ex) {
ex.printStackTrace();
}
finally {
return rs;
}
} //关闭
public void doClose(){
try {
if(rs!=null)rs.close();
if(st!=null)st.close();
if(conn!=null)conn.close();
}
catch (Exception ex) {
ex.printStackTrace();
}
}
}