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[英]How can I send form values from jsp file to controller in Spring, JSP?
[英]Send a file from JSP to controller which calls a method of interface -How do I upload a file from that request?
你好,我正在做一個項目。
希望你能幫助我解決我的問題。.我正在努力5天!
在分配給我的模塊中,我必須將文件,標題,類別,按詳細信息從JSP上傳到controller.do,后者將request
和responce
存儲在Command.java
接口中名為execute()
的方法中。
現在,當我傳遞所有Upload表單詳細信息時,它會一直處理到名為ResourceCommand.java implements Command
的類ResourceCommand.java implements Command
,該ResourceCommand.java implements Command
調用DAO並在中間停止執行!
Upload.jsp的部分代碼
<form name="myform_up" method="post" action = "Controller">
<input type="hidden" name="form_action" value="resource" />
<input type="hidden" name="action" value="insert" />
<table>
<tr>
<td>Document Title <font color="red">*</font></td></tr>
<tr>
<td><input type="text" name="name" /></td></tr>
<tr>
<td>Category <font color="red">*</font>
<select name="cat">
<option value="Java" selected >Java Material</option>
<option value="Net">.Net Material</option>
<option value="C">C and C# Material</option>
</select></td>
</tr>
<input type="hidden" name="uploadedby" value="<jsp:getProperty name="userBean" property="user" />" />
<tr>
<td>Upload A file:
<input type="file" name="file1"/></td>
</tr>
<tr>
<td><br/><input type="checkbox" name="t_condition" checked />I Had received Copyrights for this Document</td>
</tr>
<TR>
<td ALIGN="CENTER"><br/>
<INPUT class="button blue" TYPE="submit" value="Upload" />
<INPUT class="button red" TYPE="reset" value="Clear" />
</td></TR>
</TABLE>
</FORM>
Controller.java的部分代碼
public void init(ServletConfig config) throws ServletException{
super.init();
System.out.println("i am in init");
this.commands.put("login", new LoginCommand());
this.commands.put("resource", new ResourceCommand());
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("i am in doget");
processCommand(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("i am in dopost");
processCommand(request, response);
}
private void processCommand(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String formAction = request.getParameter("form_action");
System.out.println("implementing formAction = " + formAction);
Commands command = (Commands) commands.get(formAction);
command.execute(request, response);
}
}
ResourceCommand.java中的部分代碼
public class ResourceCommand extends HttpServlet implements Commands{
private static final long serialVersionUID = 1L;
public void execute(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
if ("insert".equalsIgnoreCase(request.getParameter("action"))) {
this.addResource(request, response);
}
}
private void addResource(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException{
ResourceBean ResourceBean = new ResourceBean();
mapToResourceBeans(request, ResourceBean);
String result = null;
try {
result = new ResourceDAO().uploadResource(request, ResourceBean);
} catch (Exception ex) {
System.err.println(" Error in inserting new resource");
}
if ("success".equalsIgnoreCase(result)) {
// if Block CODE
}
else {
//Else block CODE
}
}
private void mapToResourceBeans(HttpServletRequest request,
ResourceBean ResourceBean) {
ResourceBean.setName(request.getParameter("name"));
ResourceBean.setCat(request.getParameter("cat"));
ResourceBean.setUploadedby(request.getParameter("uploadedby"));
}
}
Command.java的部分代碼
public interface Commands {
public void execute(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
}
ResourceDAO.java中的部分代碼
public class ResourceDAO {
static final String SUCCESS = "success";
static final String FAILURE = "failure";
static Logger log = Logger.getLogger("com.a");
public String uploadResource(HttpServletRequest request,
ResourceBean newResource) throws FileNotFoundException {
String result = null;
PreparedStatement stmtInsert = null;
// Create a Database Connection
Connection con = ConnectionDAO.getJDBCConnection();
try {
PreparedStatement pstmt = con
.prepareStatement("INSERT INTO resource(name, cat, uploadedby, file) values(?,?,?,?)");
pstmt.setString(1, newResource.getName());
System.out.println(newResource.getName());
pstmt.setString(2, newResource.getCat());
System.out.println(newResource.getCat());
pstmt.setString(3, newResource.getUploadedby());
System.out.println(newResource.getUploadedby());
String file = request.getParameter("file1");
System.out.println("0");
File f = new File(file);
System.out.println("1");
FileInputStream fis = new FileInputStream(f);
System.out.println("2");
pstmt.setBinaryStream(4, fis, (int) f.length());
System.out.println("3");
int rows = pstmt.executeUpdate();
result = SUCCESS;
if (rows != 1) { result = FAILURE; }
} catch (SQLException ex) {
result = FAILURE;
ConnectionDAO.rollbackJDBCConnection(con);
ex.printStackTrace();
} finally {
ConnectionDAO.commitJDBCConnection(con);
ConnectionDAO.closeStatement(stmtInsert);
ConnectionDAO.closeJDBCConnection(con);
}
return result;
}
}
控制台顯示
implementing formAction = resource
Error in inserting new resource
123
Net
null
0
1
i am going back to addResource page
如果我將enctype="multipart/form-data"
放在TAG表格中,那么我會得到這個。
java.lang.NullPointerException
com.kbcss.controller.Controller.processCommand(Controller.java:57)
com.kbcss.controller.Controller.doPost(Controller.java:49)
javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
我完全迷失了。.Plz幫助...
這是第56行嗎? 前一個錯誤?
Commands command = (Commands) commands.get(formAction);
如果在commands
映射中未找到該commands
(未顯示),則可能返回null
。 您至少應檢查是否從地圖返回了有效命令。
如果找不到匹配的內容,則Map
將返回null
。 在下一行中,您將使用它,並將獲得NullPointerException
。
我發現我應該使用Serlvet 3.0來使事情正常工作。。我感謝大家為我的代碼付出了自己的努力:p ...
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