使用SpringMVC 4.0 Multipart上传图像

Question

我正在尝试使用以下代码在线上传图片。但是，由于某种原因，图像文件夹中似乎没有创建图像。不确定，我在这里做错了什么。

@RequestMapping(value="/add", method=RequestMethod.POST)
public String processAddNewProductForm(@ModelAttribute("newProduct") Product productToBeAdded, BindingResult result, HttpServletRequest request) {
    String[] supressedFields = result.getSuppressedFields();
    if(supressedFields.length > 0) {
        throw new RuntimeException("Attempting to bind disallowed fields: " + StringUtils.arrayToCommaDelimitedString(supressedFields));
    }

    MultipartFile productImage = productToBeAdded.getProductImage();

    String rootDirectory = request.getSession().getServletContext().getRealPath("/");
    if (productImage!=null && !productImage.isEmpty()) {
      try {
        productImage.transferTo(new File(rootDirectory+"resources\\images\\"+ productToBeAdded.getProductId() + ".png"));
        } catch (Exception e) {
          throw new RuntimeException("Product Image saving failed", e);
        }
    }


    productService.addProduct(productToBeAdded);
    return "redirect:/products/";

}

DispatcherServlet的

<bean id="multipartResolver"
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="maxUploadSize" value="10240000" />
</bean>

Product.java

 public class Product {

private String productId;
private String name;
private BigDecimal unitPrice;
private String description;
private String manufacturer;
private String category;
private long unitsInStock;
private long unitsInOrder;
private boolean discontinued;
private String condition;
private MultipartFile productImage;


public Product() {
super();
}

public Product(String productId, String name, BigDecimal unitPrice) {
this.productId = productId;
this.name = name;
this.unitPrice = unitPrice;
}

// add setters and getters for all the fields here

public MultipartFile getProductImage() {
return productImage;
}

public void setProductImage(MultipartFile productImage) {
this.productImage = productImage;
}

public String getProductId() {
return productId;
}

public void setProductId(String productId) {
this.productId = productId;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public BigDecimal getUnitPrice() {
return unitPrice;
}

public void setUnitPrice(BigDecimal unitPrice) {
this.unitPrice = unitPrice;
}

public String getDescription() {
return description;
}

public void setDescription(String description) {
this.description = description;
}

public String getManufacturer() {
return manufacturer;
}

public void setManufacturer(String manufacturer) {
this.manufacturer = manufacturer;
}

public String getCategory() {
return category;
}

public void setCategory(String category) {
this.category = category;
}

public long getUnitsInStock() {
return unitsInStock;
}

public void setUnitsInStock(long unitsInStock) {
this.unitsInStock = unitsInStock;
}

public long getUnitsInOrder() {
return unitsInOrder;
}

public void setUnitsInOrder(long unitsInOrder) {
this.unitsInOrder = unitsInOrder;
}

public boolean isDiscontinued() {
return discontinued;
}

public void setDiscontinued(boolean discontinued) {
this.discontinued = discontinued;
}

public String getCondition() {
return condition;
}

public void setCondition(String condition) {
this.condition = condition;
}

product.jsp

  <div class="col-md-5"> <img src="<c:url value="/resources/images/${product.productId}.png">           </c:url>" alt="image" style="width: 100%" />

Answer 1

可能还有很多问题。

首先，您将解析器命名为multipartResolver。除非您专门配置MultipartFilter，否则它会在名称filterMultipartResolver。

下查找

接下来，您在dispatcherservlet中配置了解析器。即使过滤器是一个Web元素，它也独立于任何servlet并使用根应用程序上下文。

即使您没有显示，我也认为您在MultipartFilter文件中配置了web.xml。

您似乎只是在MultipartFile添加了Product。根据javadoc ，用户负责根据需要将文件内容复制到会话级或持久性存储。临时存储将在请求处理结束时清除。你应该使用类似的东西：

private byte[] image;

public void setProductImage(MultipartFile productImage) {
    image = productImage.getBytes();
}

如果要将图像存储在产品中。否则，您应将其传输到文件（File dest = ...; productImage.tranferTo(dest);）并将名称存储在产品中。