three,
Picture display
1. Write an action of displaying a picture, the code structure is as follows:
Public class photoAdition extends action {
Private static factory string content_type = "image / gif";
Public ActionForward Perform (ActionMapping Mapping, Actionform Actionform, HttpservletRequest Request, HttpservletResponse Response)
Throws servletexception, ioException {
Response.setContentType (Content_Type);
... // Get Param EmployeeID
ServletOutputStream out = response.getOutputStream ();
InputStream in = NULL;
Try {
IN = ... // Get Blob Pic
}
Catch (throwable e) {
E.PrintStackTrace ();
}
IF (in! = NULL) {
Try {
Int Len;
BYTE BUF [] = New byte [4096];
While ((Len = In. Read (BUF, 0, 4096))! = -1) {
Out.write (buf, 0, len);
}
}
Catch (IOException IoE) {
IoE.PrintStackTrace ();
}
}
Return NULL;
}
}
2. Write the following code in the JSP page displaying the picture:
Fourth, enable ApplicationResources.properties to support Chinese display:
Go to the command prompt page, enter the bin directory under the JDK installation path, execute the command:
Native2ASCII - Encoding GB2312 ApplicationResources_ISo.properties (Original File) AllicationResources.properties (new generation file)
中 中 的 文文 in the JSP page.
However, there is still a problem that there is no solution, which is "NULL ERROR" in the JSP page. Do you have the same problem? How to solve it?
Five: The file path in Action:
An XML file is required in Action, which is not a problem with the relative path to compile, but if you don't have the file path on the server. I found a lot of solutions, I finally called the Request.GetRealPath ("/") method, the line of the line, but this method is not recommended. Do you have a better way?
Six: JSP page Display strings array:
7: How to define your JSP file issued path (Practice in Windows2000 Environment):
Open the server.xml file under the CONF folder under the Tomcat directory, find the tab
After the
Restart Tomcat, visit: / localhost: 8080 / mybwebapps /, ok!
8: How to solve the problem of remote words:
Use the big character set to set all the JSP page character sets as follows: <% @ page contenttype = "text / html; charSet = GBK"%> Note: GBK must be capitalized.
Nine: Page refresh data Repeated submission issues:
The method of solving is to use redirection. The same as the second solution:
1. Set the Redirect property in struts-config.xml to TRUE.
2. If it is a jump with parameters:
ActionForward Forward = mapping.forward ("Success");
StringBuffer bf = new stringbuffer (forward.getpath ());
bf.append ("? id = 1"); // parameter
Return New ActionForward (bf.tostring (), true);
Ten: Others:
Programming specification suggestion:
Database interface class named: * Dao.Java
Logical class named: * bo.java
Action naming: * action.java
Actionform Named: * form.java
Then a function module is placed in a packet.
They are some of the comparison of primary questions, but I hope to help you learn from the beginning of Struts, and I hope to give pointers to the questions in the text, :).
