我正在spring使用jpa和开发文档管理应用程序MySQL。该应用程序当前正在将文档及其元数据从用户Web表单createOrUpdateDocumentForm.jsp接受到控制器中DocumentController.java。但是，数据没有进入MySQL数据库。有人可以告诉我如何更改代码，以便将文档及其元数据存储在基础数据库中吗？

数据流（包括pdf文档）似乎通过以下对象：

createOrUpdateDocumentForm.jsp  //omitted for brevity, since it is sending data to controller (see below)
Document.java  
DocumentController.java  
ClinicService.java
JpaDocumentRepository.java
The MySQL database

我将总结每个对象的相关部分，如下所示：

在中jsp触发以下方法DocumentController.java：

@RequestMapping(value = "/patients/{patientId}/documents/new", headers = "content-type=multipart/*", method = RequestMethod.POST)
public String processCreationForm(@ModelAttribute("document") Document document, BindingResult result, SessionStatus status, @RequestParam("file") final MultipartFile file) {
    document.setCreated();
    byte[] contents;
    Blob blob = null;
    try {
        contents = file.getBytes();
        blob = new SerialBlob(contents);
    } catch (IOException e) {e.printStackTrace();}
    catch (SerialException e) {e.printStackTrace();}
    catch (SQLException e) {e.printStackTrace();}
    document.setContent(blob);
    document.setContentType(file.getContentType());
    document.setFileName(file.getOriginalFilename());
    System.out.println("----------- document.getContentType() is: "+document.getContentType());
    System.out.println("----------- document.getCreated() is: "+document.getCreated());
    System.out.println("----------- document.getDescription() is: "+document.getDescription());
    System.out.println("----------- document.getFileName() is: "+document.getFileName());
    System.out.println("----------- document.getId() is: "+document.getId());
    System.out.println("----------- document.getName() is: "+document.getName());
    System.out.println("----------- document.getPatient() is: "+document.getPatient());
    System.out.println("----------- document.getType() is: "+document.getType());        
    try {System.out.println("[[[[BLOB LENGTH IS: "+document.getContent().length()+"]]]]");}
    catch (SQLException e) {e.printStackTrace();}
    new DocumentValidator().validate(document, result);
    if (result.hasErrors()) {
        System.out.println("result.getFieldErrors() is: "+result.getFieldErrors());
        return "documents/createOrUpdateDocumentForm";
    }
    else {
        this.clinicService.saveDocument(document);
        status.setComplete();
        return "redirect:/patients?patientID={patientId}";
    }
}

当我通过Web表单提交的文档中jsp的controller时，System.out.println()在命令controller代码输出以下，这表明该数据实际上是越来越发送到服务器：

----------- document.getContentType() is: application/pdf
----------- document.getCreated() is: 2013-12-16
----------- document.getDescription() is: paper
----------- document.getFileName() is: apaper.pdf
----------- document.getId() is: null
----------- document.getName() is: apaper
----------- document.getPatient() is: [Patient@564434f7 id = 1, new = false, lastName = 'Frank', firstName = 'George', middleinitial = 'B', sex = 'Male', dateofbirth = 2000-11-28T16:00:00.000-08:00, race = 'caucasian']
----------- document.getType() is: ScannedPatientForms
[[[[BLOB LENGTH IS: 712238]]]]  //This indicates the file content was converted to blob

该Document.java模型是：

@Entity
@Table(name = "documents")
public class Document {
    @Id
    @GeneratedValue
    @Column(name="id")
    private Integer id;

    @ManyToOne
    @JoinColumn(name = "client_id")
    private Patient patient;

    @ManyToOne
    @JoinColumn(name = "type_id")
    private DocumentType type;

    @Column(name="name")
    private String name;

    @Column(name="description")
    private String description;

    @Column(name="filename")
    private String filename;

    @Column(name="content")
    @Lob
    private Blob content;

    @Column(name="content_type")
    private String contentType;

    @Column(name = "created")
    private Date created;

    public Integer getId(){return id;}
    public void setId(Integer i){id=i;}

    protected void setPatient(Patient patient) {this.patient = patient;}
    public Patient getPatient(){return this.patient;}

    public void setType(DocumentType type) {this.type = type;}
    public DocumentType getType() {return this.type;}

    public String getName(){return name;}
    public void setName(String nm){name=nm;}

    public String getDescription(){return description;}
    public void setDescription(String desc){description=desc;}

    public String getFileName(){return filename;}
    public void setFileName(String fn){filename=fn;}

    public Blob getContent(){return content;}
    public void setContent(Blob ct){content=ct;}

    public String getContentType(){return contentType;}
    public void setContentType(String ctype){contentType=ctype;}

    public void setCreated(){created=new java.sql.Date(System.currentTimeMillis());}
    public Date getCreated() {return this.created;}

    @Override
    public String toString() {return this.getName();}
    public boolean isNew() {return (this.id == null);}

}

ClinicService.java从中调用的代码DocumentController是：

private DocumentRepository documentRepository;
private PatientRepository patientRepository;

@Autowired
public ClinicServiceImpl(DocumentRepository documentRepository, PatientRepository patientRepository) {
    this.documentRepository = documentRepository;
    this.patientRepository = patientRepository;
}

@Override
@Transactional
public void saveDocument(Document doc) throws DataAccessException {documentRepository.save(doc);}

中的相关代码JpaDocumentRepository.java是：

@PersistenceContext
private EntityManager em;

@Override
public void save(Document document) {
    if (document.getId() == null) {this.em.persist(document);}
    else {this.em.merge(document);}
}

最后，创建数据库的SQL代码的相关部分包括：

CREATE TABLE IF NOT EXISTS documenttypes (
  id INT(4) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(80),
  INDEX(name)
);

CREATE TABLE IF NOT EXISTS patients (
  id INT(4) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
  first_name VARCHAR(30),
  middle_initial VARCHAR(5), 
  last_name VARCHAR(30),
  sex VARCHAR(20), 
  date_of_birth DATE,
  race VARCHAR(30), 
  INDEX(last_name)
);

CREATE TABLE IF NOT EXISTS documents (
  id int(11) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
  client_id int(4) UNSIGNED NOT NULL,
  type_id INT(4) UNSIGNED, 
  name varchar(200) NOT NULL,
  description text NOT NULL,
  filename varchar(200) NOT NULL,
  content mediumblob NOT NULL, 
  content_type varchar(255) NOT NULL,
  created timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (client_id) REFERENCES patients(id),
  FOREIGN KEY (type_id) REFERENCES documenttypes(id)
);

我要对此代码进行哪些更改，以便使用将代码保存document在数据库documents表中？MySQL``jpa