做一个类连接数据库?为什么要这么做?
public static Connection getConn(){
Connection conn = null;
String driverclass = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
String url = "jdbc:microsoft:sqlserver://localhost:1433;databasename=webstore";
String user = "sa";
String password = "";
try {
Class.forName(driverclass);
}
catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
try {
conn = DriverManager.getConnection(url, user, password);
}
catch (SQLException ex1) {
ex1.printStackTrace();
}
return conn;
}
/**
* 关闭数据库资源
* @param rs ResultSet
* @param st Statement
* @param conn Connection
*/
public static void tryCloseDB(ResultSet rs,Statement st,Connection conn){
if (rs != null){
try {
rs.close();
}
catch (SQLException ex) {
}
}
if(st != null){
try {
st.close();
}
catch (SQLException ex1) {
}
}
if(conn != null){
try {
conn.close();
}
catch (SQLException ex2) {
}
}
}
/**
* 执行数据库的增、删、改操作
* @param sql String
* @return boolean
*/
public static boolean executeSql(String sql){
Connection conn = getConn();
Statement st = null;
int i = -1;
try {
st = conn.createStatement();
i = st.executeUpdate(sql);
}
catch (SQLException ex) {
}finally{
tryCloseDB(null,st,conn);
}
if (i>0){
return true;
}else{
return false;
}
}
}
要用到static?