MultipartFile / blob problem saving in database

Hi i want to upload an image and store it the database i use spring mvc & hibernate

here is the model

import java.sql.Blob;
import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Lob;
import javax.persistence.Table;

@Entity
@Table(name = "article")
public class Article {

@Id
@GeneratedValue
@Column(name = "article_id")
private Long articleId;

@Column(name = "article_name", nullable = false, length=20)
private String articleName;

@Column(name = "article_desc", nullable = false)
private String articleDesc;

@Column(name = "d开发者_运维知识库ate_added")
private Date addedDate;

 @Lob
    private Blob content;
public Article() {      
}

public Long getArticleId() {
    return articleId;
}

public void setArticleId(Long articleId) {
    this.articleId = articleId;
}

public String getArticleName() {
    return articleName;
}

public void setArticleName(String articleName) {
    this.articleName = articleName;
}

public String getArticleDesc() {
    return articleDesc;
}

public void setArticleDesc(String articleDesc) {
    this.articleDesc = articleDesc;
}

public Date getAddedDate() {
    return addedDate;
}

public void setAddedDate(Date addedDate) {
    this.addedDate = addedDate;
}   

public String toString(){
    return this.articleName;
}

public void setContent(Blob content) {
    this.content = content;
}

public Blob getContent() {
    return content;
}

}

here is the controller (methode to save the article)

  @RequestMapping(value = "/save", method = RequestMethod.POST)
public String save(
        @ModelAttribute("article") Article article,
        @RequestParam("file") MultipartFile file) {



    try {
        Blob blob = Hibernate.createBlob(file.getInputStream());


        article.setContent(blob);

    } catch (IOException e) {
        e.printStackTrace();
    }

    try {
         articleService.addArticle( article);
    } catch(Exception e) {
        e.printStackTrace();
    }

    return "redirect:/articles.html";
}

when i want to save a new article with my JSP form i have this errors

33266 [http-8080-2] DEBUG org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerExceptionResolver - Resolving exception from handler [net.roseindia.controller.ArticleController@10e8647]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found 33270 [http-8080-2] DEBUG org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver - Resolving exception from handler [net.roseindia.controller.ArticleController@10e8647]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found 33270 [http-8080-2] DEBUG org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver - Resolving exception from handler [net.roseindia.controller.ArticleController@10e8647]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found

can any body help me

i found the problem in the jsp form i should specify enctype="multipart/form-data"