从JSP发送文件到调用接口方法的控制器 - 如何从该请求上传文件？ [英] Send a file from JSP to controller which calls a method of interface -How do I upload a file from that request?

问题描述

希望你能帮助我解决我的问题..我正努力工作5天!!

/ p>

在分配给我的模块中，我必须将一个文件，标题，类别，由JSP上传的细节上传到controller.do，它存储 execute（）方法中请求和 responce c $ c> Command.java 界面。

现在当我通过所有的上传表单细节时，一直到名为 ResourceCommand.java的类实现Command ，它调用DAO并在中间停止执行!!!!

来自 Upload.jsp 的部分代码

 < form name =myform_up method =postaction =Controller> 
< input type =hiddenname =form_actionvalue =resource/> 
< input type =hiddenname =actionvalue =insert/> 
< table> 
< tr> 
< td>文件标题< font color =red> *< / font>< / td>< / tr> 
< tr> 
< td>< input type =textname =name/>< / td>< / tr> 
< tr> 
< td>类别< font color =red> *< / font> 
< select name =cat> 
< option value =Javaselected> Java Material< / option> 
< option value =Net> .Net Material< / option> 
< option value =C> C and C＃Material< / option> 
< / select>< / td> 
< / tr> 
< input type =hiddenname =uploadedbyvalue =< jsp：getProperty name =userBeanproperty =user/> /> 
< tr> 
< td>上传档案：
< input type =filename =file1/>< / td> 
< / tr> 
< tr> 
< td>< br />< input type =checkboxname =t_conditionchecked />我已收到此文件的版权< / td> 
< / tr> 
< TR> 
< td ALIGN =CENTER>< br /> 
< INPUT class =button blueTYPE =submitvalue =上传/> &安培; NBSP;&安培; NBSP;&安培; NBSP;&安培; NBSP;&安培; NBSP;&安培; NBSP; 
< INPUT class =button redTYPE =resetvalue =Clear/> 
< / td>< / TR> 
< / TABLE> 
< / FORM> 
  

来自 Controller.java 的部分代码

  public void init（ServletConfig config）throws ServletException {
 super.init（）; 
 
 System.out.println（我在init）; 
 
 this.commands.put（login，new LoginCommand（））; 
 this.commands.put（resource，new ResourceCommand（））; 
 
 
 $ b protected void doGet（HttpServletRequest request，HttpServletResponse response）throws ServletException，IOException {$ b $ 
 processCommand（request，response）; 
 
 $ b $保护无效doPost（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException {
 System.out.println（我在dopost）; 
 processCommand（request，response）; 
 
 $ b $ private void processCommand（HttpServletRequest request，HttpServletResponse response）throws ServletException，IOException {
 
 String formAction = request.getParameter（form_action）; 
 System.out.println（implementation formAction =+ formAction）; 
命令command =（Commands）commands.get（formAction）; 
 command.execute（request，response）; 
 
 
 
 
 $ b 
  ResourceCommand.java   
 
 
  public class ResourceCommand extends HttpServlet implements命令{
 private static final long serialVersionUID = 1L; 
 public void execute（HttpServletRequest request，HttpServletResponse response）
 throws ServletException，IOException {
 $ b $ if（insert.equalsIgnoreCase（request.getParameter（action）））{ 
 this.addResource（request，response）; 
 
 
 
 private void addResource（HttpServletRequest请求，
 HttpServletResponse响应）throws ServletException，IOException {
 
 ResourceBean ResourceBean = new ResourceBean （）; 
 mapToResourceBeans（request，ResourceBean）; 
 
 String result = null; 
尝试{
 result = new ResourceDAO（）。uploadResource（request，ResourceBean）; 
} catch（Exception ex）{
 System.err.println（Error in insertion new resource）; 
 
 if（success.equalsIgnoreCase（result））{
 // if Block CODE 
} 
 
 else {
 / / else块代码
} 
} 
 private void mapToResourceBeans（HttpServletRequest请求，
 ResourceBean ResourceBean）{
 ResourceBean.setName（request.getParameter（name）） ; 
 ResourceBean.setCat（request.getParameter（cat））; 
 ResourceBean.setUploadedby（request.getParameter（uploadedby））; 
 
 
 
 
 $ b 
  Command.java   
 
 
  public interface命令{
 $ b public void execute（HttpServletRequest request，HttpServletResponse response）throws ServletException，IOException; 
 
 $ b $ / code> 
来自 ResourceDAO.java  
 
 
  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; 
 //创建数据库连接
连接con = ConnectionDAO.getJDBCConnection（）; 
 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）; 
 
文件f =新文件（文件）; 
 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（）; 
 
结果= 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）; 
} 
返回结果; 
 
 
 
 
 $ b $ p $控制台显示
 
 
 实现formAction =资源
插入新资源时出错
 123 
净
空
 0 
 1 
i回到addResource页面
  
如果我把 enctype =multipart / form-data然后我会得到这个.. code> 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）
  
  $ b 
 我完全失去了帮助......   
 
我感谢你们所有的努力给我的代码：p ... 
 
hello every one i'm working on a project.

Hope u can help me in solving my problem.. I'm struggling for 5 DAYS!!

in a module which is assigned to me I have to upload a file, title, category, uploadedby details from a JSP to controller.do which stores the request and responce in a method named execute() which is present in Command.java Interface.

now when i pass all the Upload form details,, it goes all the way across to a class named ResourceCommand.java implements Command which calls a DAO and stops execution in middle !!!!

part of code from Upload.jsp
<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" /> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
            <INPUT class="button red" TYPE="reset" value="Clear" />
            </td></TR>
    </TABLE>
</FORM>
part of code from Controller.java
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);            
    }
}
part of code from ResourceCommand.java
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"));             
    }   
}
part of code from Command.java
public interface Commands {

    public void execute(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;

}
part of code from ResourceDAO.java
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;
        }    
    }
Console Display..
implementing formAction = resource
 Error in inserting new resource
123
Net
null
0
1
i am going back to addResource page
If i place   enctype="multipart/form-data" in form TAG.. then i will get this..
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) 
I am completely LOST..Plz HELP...
解决方案
i found out that i should use Serlvet 3.0 to make thing work..
I thank u all for giving some of u'r  effort to my code :p ...

                        
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