-1
我在谷歌App Engine的dadastore以下類對象,我可以從「數據存儲瀏覽器」看到他們:Google App Engine如何從servlet中獲取對象?
import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.IdentityType;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
@PersistenceCapable(identityType=IdentityType.APPLICATION)
public class Contact_Info_Entry implements Serializable
{
@PrimaryKey
@Persistent(valueStrategy=IdGeneratorStrategy.IDENTITY)
Long Id;
public static final long serialVersionUID=26362862L;
String Contact_Id="",First_Name="",Last_Name="",Company_Name="",Branch_Name="",Address_1="",Address_2="",City="",State="",Zip="",Country="";
double D_1,D_2;
boolean B_1,B_2;
Vector<String> A_Vector=new Vector<String>();
public Contact_Info_Entry() { }
......
}
我的Java應用程序怎樣才能從一個servlet URL的對象?舉例來說,如果有誰是CONTACT_ID Contact_Info_Entry的一個實例是 「ABC-123」,和我的應用程序ID爲:NM-java的
當我的Java程序訪問的網址:
"http://nm-java.appspot.com/Check_Contact_Info?Contact_Id=ABC-123
如何將Check_Contact_Info的servlet從數據存儲獲取對象並將其返回給我的應用程序?
public class Check_Contact_Info_Servlet extends HttpServlet
{
static boolean Debug=true;
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException
{
}
...
protected void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { doGet(request,response); }
}
對不起,我需要更加具體,如何發送對象出的反應如何?
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException
{
PrintWriter out=response.getWriter();
Contact_Info_Entry My_Contact_Entry;
... get My_Contact_Entry from datastore ...
??? How to send it out in the "response" ???
}
弗蘭克
謝謝,我也需要這部分! – Frank 2010-04-27 14:23:19
@BalusC:是的,我在之前的其他程序中使用過OutputStream或Writer,但是我用它們發送了beck html字符串,而不是對象的實例,在這種情況下,「PrintWriter out = response.getWriter() ;」發回「Contact_Info_Entry My_Contact_Entry」?這是我卡住的地方。 – Frank 2010-04-27 14:44:22
@Frank:看看ObjectOutputStream – Thilo 2010-04-27 14:57:51