obtention d'une valeur nulle à partir de request.getparameter ("name"); com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException

Question

faire exception whem i cliqué sur le bouton soumettre

tout mon code fonctionne bien, mais quand j'étais ajouter du code pour télécharger l'image cette erreur se produira

à ces positions je l'ai fait les changements 1. en html pour enctype = "multipart/form-data" nouvellement ajouté 2. jsp ajouté Enregistrer l'image dans le projet derectory

me donner une solution ......

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: colonne 'nom' ne peut pas être nul

ma forme html

<form method="post" enctype="multipart/form-data" > 
    <div class="intro"> 
    <h1>Setup your Details</h1> 
    <h2></h2> 
</div> 
<% 
try{ 
Class.forName("com.mysql.jdbc.Driver"); 
Connection con = 
DriverManager.getConnection("jdbc:mysql://localhost:3306/slambook","root", 
""); 
Statement st = con.createStatement(); 
String user = (String) session.getAttribute("userid"); 
String qry = "select * from userdetails where `userid`='"+user+"'"; 
ResultSet result = st.executeQuery(qry); 

while(result.next()){ 
//id = result.getInt("id"); 

%>  
<input type="text" placeholder="Name" name="name" value="<%=result.getString("name")%>" required/> 
<input type="number" placeholder="Contact No." name="cno" value="<%=result.getString("cno")%>" required/> 
Choose File : <input type="file" name="file" required> 
<textarea placeholder="Address" name="address" rows="4"><%=result.getString("address")%></textarea> 
<input type="date" name="dob" value="<%=result.getString("dob")%>"/> 
<input type="text" placeholder="Dream" name="dream" value="<%=result.getString("dream")%>" required/> 
<input type="text" placeholder="Favorite Personality" name="favperson" value="<%=result.getString("favperson")%>" required/> 
<input type="text" placeholder="Secret Crush" name="crush" value="<%=result.getString("crush")%>"/> 

<%if(result.getString("userid").equals(null)) 
    { 
     %><input type="submit" name="btnsave" value="Save Details" onclick="form.action='saveuserdetails.jsp';"/> 
     <input type="submit" name="btnupdate" value="update Details" onclick="form.action='updateuserdetails.jsp';"/> 
     <input type="reset" value="Clear" style="float: right;"><% 
    } 
    else 
    {%> 
     <input type="submit" name="btnupdate" value="update Details" onclick="form.action='updateuserdetails.jsp';"/> 
     <input type="reset" value="Clear" style="float: right;"><% 
    } 

} 
} 
catch(Exception ex) 
{ 
    out.println(ex); 
} 
%> 

c'est ma mise à jour jsp

<%@page import="java.io.*"%> 
    <%@ page import ="java.sql.*,java.io.*,java.util.*" %> 
    <% 
    String uid = (String) session.getAttribute("userid"); 
    String name = request.getParameter("name");  
    String cno = request.getParameter("cno"); 
    //String picaddress = request.getParameter("file"); 
    String address= request.getParameter("address"); 
    String dob= request.getParameter("dob"); 
    String dream= request.getParameter("dream"); 
    String favperson= request.getParameter("favperson"); 
    String crush= request.getParameter("crush"); 

    String saveFile = ""; 
    String contentType = request.getContentType(); 
    if((contentType != null)&&(contentType.indexOf("multipart/form-data")>=0)) 
    { 
    DataInputStream in = new DataInputStream(request.getInputStream()); 
    int formDataLength = request.getContentLength(); 
    byte dataBytes[] = new byte[formDataLength]; 
    int byteRead = 0; 
    int totalBytesRead = 0; 
    while(totalBytesRead < formDataLength) 
    { 
     byteRead = in.read(dataBytes, totalBytesRead, formDataLength); 
     totalBytesRead +=byteRead; 
    } 
    String file = new String(dataBytes); 
    saveFile = file.substring(file.indexOf("filename=\"")+10); 
    saveFile = saveFile.substring(0,saveFile.indexOf("\n")); 
    saveFile = 
    saveFile.substring(saveFile.lastIndexOf("\\")+1,saveFile.indexOf("\"")); 
    int lastIndex = contentType.lastIndexOf("="); 
    String boundry = contentType.substring(lastIndex 
    +1,contentType.length()); 
    int pos; 
    pos = file.indexOf("filename=\""); 
    pos = file.indexOf("\n",pos)+1; 
    pos = file.indexOf("\n",pos)+1; 
    pos = file.indexOf("\n",pos)+1; 
    int boundryLocation = file.indexOf(boundry,pos)-4; 
    int startPos = ((file.substring(0,pos)).getBytes()).length; 
    int endPos = ((file.substring(0, boundryLocation)).getBytes()).length; 
    File ff =new File("C:/Users/Jarvis/Documents/NetBeansProjects/Slambook/web/ProfileImages/"+saveFile); 
    FileOutputStream fileOut = new FileOutputStream(ff); 
    fileOut.write(dataBytes,startPos,(endPos-startPos)); 
    fileOut.flush(); 
    fileOut.close(); 


    try { 
Class.forName("com.mysql.jdbc.Driver"); 
Connection con = 
    DriverManager.getConnection("jdbc:mysql://localhost:3306/slambook", 
     "root", ""); 
out.println(address); 
PreparedStatement ps = con.prepareStatement("update userdetails set name =?,cno = ?, address = ?,dob = ?,dream = ?,favperson = ?,crush = ?,imgstream = ? where userid = ?"); 
ps.setString(9, uid); 
ps.setString(1, name); 
ps.setString(2, cno); 

ps.setString(3, address); 
ps.setString(4, dob); 
ps.setString(5, dream); 
ps.setString(6, favperson); 
ps.setString(7, crush); 
ps.setString(8,ff.getPath()); 
ps.executeUpdate(); 
response.sendRedirect("userdetails.jsp"); 
} 
    catch(Exception e) 
    { 
    out.println(e); 
    } 
    } 
%> 

Answer 1

Afin d'attraper spécifique SQLException, besoin de comparer avec l'état SQl en utilisant la méthode getSQLState(). Ex: SQl State 23 pour violation de l'intégrité des données.

  `catch (SQLException ex) { 
       if (ex.getSQLState().startsWith("23")) { 
         JOptionPane.showMessageDialog(null, "Duplicate"); 
       } 
      }` 

Found from here