private static String DRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver";
private static String URL="jdbc:sqlserver://localhost:1433;Database=NewsManagerSystem";
private Connection conn;
private PreparedStatement pstmt;
private ResultSet rs;
private void disposeResultSet(ResultSet rs){
try{
if(rs!=null){
rs.close();
}
}catch(SQLException e){
e.printStackTrace();
}
}
private void disposePstmt(PreparedStatement pstmt){
try{
if(pstmt!=null){
pstmt.close();
}
}catch(SQLException e){
e.printStackTrace();
}
}
private void disposeConn(Connection conn){
try {
if(conn!=null)
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
private void getConnection()throws SQLException{
try{
Class.forName(DRIVER);
}catch(ClassNotFoundException e){
e.printStackTrace();
}
conn= DriverManager.getConnection(URL,"Windy_World","Windy_World");
}
@Override
public Object createEntity(Class<?> c,ResultSet rs)
throws ClassNotFoundException, SecurityException, IllegalArgumentException, NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
Object obj= c.newInstance();
try{
ResultSetMetaData metaData=rs.getMetaData();
for(int i=1;i<=metaData.getColumnCount();i++){
String methodName=String.format("set%s",metaData.getColumnName(i));
Object value=rs.getObject(i);
Class<?> paramType=Class.forName(metaData.getColumnClassName(i));
invokingSetters(obj,methodName,value,paramType);
}
}catch(SQLException e){
e.printStackTrace();
}
return obj;
}
private void invokingSetters(Object obj,String targetMethod,Object values,Class<?> parameterTypes)
throws SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException{
//System.out.println(targetMethod+"-----"+parameterTypes);
Method m=obj.getClass().getMethod(targetMethod, parameterTypes);
m.invoke(obj, values);
}
public <T> Object querySingle(Class<T> c,String sqlStr,Object... params)
throws SecurityException, IllegalArgumentException, ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException{
Object returnValue=null;
try{
this.getConnection();
pstmt=conn.prepareStatement(sqlStr);
if(params!=null){
for(int i=0;i<params.length;i++){
pstmt.setObject(i+1, params[i]);
}
}
rs= pstmt.executeQuery();
if(rs.next()){
returnValue= createEntity(null, rs);
}
}catch(SQLException e){
e.printStackTrace();
}finally{
if(rs!=null)
disposeResultSet(rs);
if(pstmt!=null)
disposePstmt(pstmt);
if(conn!=null)
disposeConn(conn);
}
return returnValue;
}
在querySingle() 中指定Class 有点不太好。。。怎样写更好呢？？