修改数据出现java.lang.NullPointerException！麻烦大家了！

[zengjava]

ProductInfo.java

package com.myboxcs.bean.product;

``````此处省略``````

@Entity
public class ProductInfo implements Serializable{

	/**
	 * 
	 */
	private static final long serialVersionUID = -1136568171160218438L;
	private Integer Id;
	private String code; //货号
	private String name;//产品名称	
	private Brand brand;//品牌
	private String model;//型号
	private Float baseprice;//底价
	private Float marketprice;//市场价
	private Float sellprice;//销售价
	private Integer weight;//重量
	private String description;//产品介绍
	private String buyexplain;//购买说明
	private Boolean visible = true;//是否可见
	private productType type;//产品类型
	private Date createdate = new Date();//创建时间
	private Integer clickcount = 1;//人气指数
	private Integer sellcount = 0;//销售量
	private Boolean commend = false;//是否推荐
	private Sex sexrequest = Sex.NONE;//性别要求
	private Set<ProductStyle> styles= new HashSet<ProductStyle>();
	
	@OneToMany(cascade={CascadeType.REMOVE,CascadeType.PERSIST},mappedBy="product")
	public Set<ProductStyle> getStyles() {
		return styles;
	}
	public void setStyles(Set<ProductStyle> styles) {
		this.styles = styles;
	}
	public void removestyles(ProductStyle styles){
		if(this.styles.contains(styles)){
			this.styles.remove(styles);
			styles.setProduct(null);
		}
	}
	public void addstyles(ProductStyle styles){
		if(!this.styles.contains(styles)){
			this.styles.add(styles);
			styles.setProduct(this);
		}
	}

//////////////////////////////////////////////////////
ProductStyle.java 样式

package com.myboxcs.bean.product;
``````此处省略``````
@Entity
public class ProductStyle implements Serializable{
	/**
	 * 
	 */
	private static final long serialVersionUID = -772326910196394263L;
	private Integer id;
	private String name;//样式名称
	private String imagename;//图片
	private Boolean visible=true;//是否可见
	private ProductInfo product;
	
	public ProductStyle() {}
	
	public ProductStyle(String name, String imagename) {
		this.name = name;
		this.imagename = imagename;
	}
	@ManyToOne(cascade=CascadeType.REFRESH,optional=false)
	@JoinColumn(name="productid")
	public ProductInfo getProduct() {
		return product;
	}
	public void setProduct(ProductInfo product) {
		this.product = product;
	}
	@Id @GeneratedValue
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	@Column(length=30)
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Column(length=80)
	public String getImagename() {
		return imagename;
	}
	public void setImagename(String imagename) {
		this.imagename = imagename;
	}
	@Column(nullable=false)
	public Boolean getVisible() {
		return visible;
	}
	public void setVisible(Boolean visible) {
		this.visible = visible;
	}
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		return result;
	}
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		final ProductStyle other = (ProductStyle) obj;
		if (id == null) {
			if (other.id != null)
				return false;
		} else if (!id.equals(other.id))
			return false;
		return true;
	}
	
}

///////////////////////////////////////////////////////
ProductInfoServiceTest.java 测试的时候是成功的 主要是update方法

package junit.test;

``````此处省略``````

public class ProductInfoServiceTest {
	public static ApplicationContext cxt;
	public static ProductInfoService productInfoService;

	@BeforeClass
	public static void setUpBeforeClass() throws Exception {
    try {
		cxt = new ClassPathXmlApplicationContext("beans.xml");
		productInfoService= (ProductInfoService)cxt.getBean("productInfoServiceBean");
	} catch (RuntimeException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	}
	@Test
	public void testSave() {
		ProductInfo product =new ProductInfo();
		product.setName("含笑半步颠");
		product.setBaseprice(100f);
		product.setBrand(new Brand("063e5af7-30de-41a7-ad95-dbe8c32bc2e7"));
		product.setCode("XW001");
		product.setDescription("居家旅行必备良药");
		product.setMarketprice(200f);
		product.setSellprice(150f);
		product.setModel("TNT");
		product.setSexrequest(Sex.NONE);
		product.addstyles(new ProductStyle("蓝瓶","xxxx.gif"));
		product.setType(new productType(32));
		product.setWeight(50);
         productInfoService.save(product);
	}
	@Test
	public void testupdate(){
	ProductInfo product = productInfoService.find(ProductInfo.class, 2);
	product.setName("最春哥");
	product.setBaseprice(100f);
	product.setSellprice(200f);
	product.setMarketprice(150f);
    product.setBrand(new Brand("063e5af7-30de-41a7-ad95-dbe8c32bc2e7"));
    product.setDescription("cc");
	product.setBuyexplain("ffff");
	product.setCode("ddd");
	product.setModel("1010");
	product.setSexrequest(Sex.NONE);
	product.setWeight(150);
	product.setType(new productType(32));
	productInfoService.update(product);
	}

}

不过在jsp页面中使用update方法就会报错
exception

javax.servlet.ServletException: java.lang.NullPointerException
org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:520)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:427)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:228)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:112)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)


root cause

java.lang.NullPointerException
com.myboxcs.web.action.product.ProductManageAction.edit(ProductManageAction.java:152)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:269)
org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:170)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:425)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:228)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:112)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)

///////////////////////////////////////////

[aoli444]

不要想着什么都让别人帮你解决，这个只要debug下，很快都能找到原因。

[zengjava]

ProductManageAction.java

package com.myboxcs.web.action.product;
此处省略
@Controller("/control/product/manage")
public class ProductManageAction extends DispatchAction {
	@Resource (name="productInfoServiceBean")
	 private ProductInfoService productInfoService;
	@Resource(name="brandServiceBean")
	private BrandService brandService;
	@Resource (name="productTypeServiceBean")
	 private ProductTypeService productTypeService;
	/**
	 * 
	 选择类别
此处省略
	/**
	 * 
	 修改界面
	 */
	public ActionForward editUI(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		ProductForm formbean=(ProductForm) form;
		ProductInfo product=productInfoService.find(ProductInfo.class, formbean.getProductid());
		formbean.setBaseprice(product.getBaseprice());
		if(product.getBrand()!=null) formbean.setBrandid(product.getBrand().getCode());
		formbean.setBuyexplain(product.getBuyexplain());
		formbean.setCode(product.getCode());
		formbean.setDescription(product.getDescription());
		formbean.setMarketprice(product.getMarketprice());
		formbean.setModel(product.getModel());
		formbean.setName(product.getName());
		formbean.setSex(product.getSexrequest().toString());
		formbean.setTypeid(product.getType().getTypeid());
		formbean.setWeight(product.getWeight());
		formbean.setSellprice(product.getSellprice());
		request.setAttribute("brands", brandService.getScrollData(Brand.class).getResultlist());
		request.setAttribute("typename", product.getType().getGoodsname());
		return mapping.findForward("edit");
	}
	
	/**
	 * 
	 添加界面
	 */
	public ActionForward addUI(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		ProductForm formbean=(ProductForm) form;
		request.setAttribute("brands", brandService.getScrollData(Brand.class).getResultlist());
		return mapping.findForward("add");
	}
	
	/**
	 * 
	 添加产品
	 */
	public ActionForward add(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		ProductForm formbean=(ProductForm) form;
		ProductInfo product = new ProductInfo();
		product.setName(formbean.getName());
		product.setBaseprice(formbean.getBaseprice());
		product.setSellprice(formbean.getSellprice());
		product.setMarketprice(formbean.getMarketprice());
		if(formbean.getBrandid()!=null && "".equals(formbean.getBrandid().trim())){
			product.setBrand(new Brand(formbean.getBrandid()));
		}
		product.setDescription(formbean.getDescription());
		product.setBuyexplain(formbean.getBuyexplain());
		product.setCode(formbean.getCode());
		product.setModel(formbean.getModel());
		product.setSexrequest(Sex.valueOf(formbean.getSex()));
		product.setWeight(formbean.getWeight());
		product.setType(new productType(formbean.getTypeid()));
		if(formbean.getImagefile()!=null && formbean.getImagefile().getFileSize()>0){
			String ext=formbean.getImagefile().getFileName().substring(formbean.getImagefile().getFileName().lastIndexOf("."));
			String imagename=UUID.randomUUID().toString()+ext;
			product.addstyles(new ProductStyle(formbean.getStylename(),imagename));
			productInfoService.save(product);
        String logopathdir="/images/product/"+ formbean.getTypeid()+"/"+product.getId()+"/prototype";
			String logorealpathdir = request.getSession().getServletContext().getRealPath(logopathdir);
		    File logosavedir= new File(logorealpathdir);
		    if(!logosavedir.exists()) logosavedir.mkdirs();
		    FileOutputStream fileoutstream = new FileOutputStream(new File(logorealpathdir,imagename));
		    fileoutstream.write(formbean.getImagefile().getFileData());
		    fileoutstream.close();
		    //String logopath ="/myboxcs"+logopathdir+"/"+imagename;
		}
		request.setAttribute("massage", "添加成功");
		return mapping.findForward("massage");
	}	
	/**
	 * 
	 产品修改
	 */
	public ActionForward edit(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		ProductForm formbean=(ProductForm) form;
		ProductInfo product = productInfoService.find(ProductInfo.class, formbean.getProductid());
		product.setName(formbean.getName());
		product.setBaseprice(formbean.getBaseprice());
		product.setSellprice(formbean.getSellprice());
		product.setMarketprice(formbean.getMarketprice());
		if(formbean.getBrandid()!=null && "".equals(formbean.getBrandid().trim())){
			product.setBrand(new Brand(formbean.getBrandid()));
		}
		product.setDescription(formbean.getDescription());
		product.setBuyexplain(formbean.getBuyexplain());
		product.setCode(formbean.getCode());
		product.setModel(formbean.getModel());
		product.setSexrequest(Sex.valueOf(formbean.getSex()));
		product.setWeight(formbean.getWeight());
		product.setType(new productType(formbean.getTypeid()));
		productInfoService.update(product);
		request.setAttribute("massage", "修改成功");
		return mapping.findForward("massage");
	}		
}

[zengjava]

/////////////////////////////
edit_product.jsp

<%@ page contentType="text/html;charset=UTF-8" %>
<%@ include file="/WEB-INF/page/share/taglib.jsp" %>
<html>
<head>
<title>修改产品</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link rel="stylesheet" href="/myboxcs/css/vip.css" type="text/css">
<SCRIPT language=JavaScript src="/myboxcs/js/FoshanRen.js"></SCRIPT>
<script type="text/javascript" src="/myboxcs/js/jscripts/tiny_mce/tiny_mce.js"></script>
<script language="javascript" type="text/javascript">
tinyMCE.init({
	language : "zh_cn",
	mode : "textareas",
	theme : "advanced",
	//width : "500",
	plugins : "table,save,advhr,advimage,advlink,emotions,iespell,insertdatetime,preview,zoom,flash,searchreplace,print,contextmenu",
	theme_advanced_buttons1_add_before : "save,separator",
	theme_advanced_buttons1_add : "fontselect,fontsizeselect",
	theme_advanced_buttons2_add : "separator,insertdate,inserttime,preview,zoom,separator,forecolor,backcolor",
	theme_advanced_buttons2_add_before: "cut,copy,paste,separator,search,replace,separator",
	theme_advanced_buttons3_add_before : "tablecontrols,separator",
	theme_advanced_buttons3_add : "emotions,iespell,flash,advhr,separator,print",
	theme_advanced_toolbar_location : "top",
	theme_advanced_toolbar_align : "left",
	theme_advanced_path_location : "bottom",
	plugin_insertdate_dateFormat : "%Y-%m-%d",
	plugin_insertdate_timeFormat : "%H:%M:%S",
	extended_valid_elements : "a[name|href|target|title|onclick],img[class|src|border=0|alt|title|hspace|vspace|width|height|align|onmouseover|onmouseout|name],hr[class|width|size|noshade],font[face|size|color|style],span[class|align|style]",
	external_link_list_url : "example_data/example_link_list.js",
	external_image_list_url : "example_data/example_image_list.js",
	flash_external_list_url : "example_data/example_flash_list.js"
});

function Formfield(name, label){
	this.name=name;
	this.label=label;
}
function verifyForm(objForm){
	tinyMCE.triggerSave();//手动把iframe的值赋给textarea表单元素
	var list  = new Array(new Formfield("name", "产品名称"),new Formfield("typeid", "产品类型"),
	new Formfield("baseprice", "产品底价"),new Formfield("marketprice", "产品市场价")
	,new Formfield("sellprice", "产品销售价"),new Formfield("description", "产品描述"));
	for(var i=0;i<list.length;i++){
		var objfield = eval("objForm."+ list[i].name);		
		if(trim(objfield.value)==""){
			alert(list[i].label+ "不能为空");
			if(objfield.type!="hidden" && objfield.focus()) 
				objfield.focus();
			return false;
		}
	}
	
	var brandid=objForm.brandid.value;	
	if(brandid=="0")
	{
		alert("请选择品牌");
		return false;
	}	
    return true;
}
function SureSubmit(objForm){
	if (verifyForm(objForm)) objForm.submit();
} 


</script>
</head>

<body bgcolor="#FFFFFF" text="#000000" leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
<html:form action="/control/product/manage" enctype="multipart/form-data" method="post">
<input type="hidden" name="method" value="edit">
<input type="hidden" name="typeid">
<input type="hidden" name="productid">
  <table width="98%" border="0" cellspacing="1" cellpadding="3" align="center">
    <tr bgcolor="6f8ac4"> 
      <td colspan="2" ><font color="#FFFFFF">添加产品：</font></td>
    </tr>
    <tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">产品名称  ：</div></td>
      <td width="75%"><html:text property="name" size="50" maxlength="40"/><font color="#FF0000">*</font></td>
    </tr>
    <tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">产品类别<font color="#FF0000">*</font>  ：</div></td>
      <td width="75%"> <input type="text" name="v_type_name" disabled="true" size="30" value="${typename}"/>       	
        <input type="button" name="select" value="选择..." onClick="javaScript:winOpen('<html:rewrite action="/control/product/manage"/>?method=selectUI','列表',600,400)">(<a href="<html:rewrite action='/control/product/type/manage'/>?method=addUI">添加产品类别</a>)
      </td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">底(采购)价 ：</div></td>
      <td width="75%"> <html:text property="baseprice" size="10" maxlength="10" onkeypress="javascript:InputLongNumberCheck()"/>元 <font color="#FF0000">*</font></td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">市场价 ：</div></td>
      <td width="75%"> <html:text property="marketprice" size="10" maxlength="10" onkeypress="javascript:InputLongNumberCheck()"/>元 <font color="#FF0000">*</font></td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">销售价 ：</div></td>
      <td width="75%"> <html:text property="sellprice" size="10" maxlength="10" onkeypress="javascript:InputLongNumberCheck()"/>元 <font color="#FF0000">*</font></td>
    </tr>
    <tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">货号 ：</div></td>
      <td width="75%"> <html:text property="code" size="20" maxlength="30"/>(注:供货商提供的便于产品查找的编号)</td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">品牌 ：</div></td>
      <td width="75%">
      <html:select property="brandid">
<html:optionsCollection name="brands" label="name" value="code"/>
</html:select>(<a href="<html:rewrite action='/control/brand/manage'/>?method=addUI")>添加品牌</a>)</td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">适用性别 ：</div></td>
      <td width="75%">
      <html:select property="sex">
    <html:option value="NONE">男女不限</html:option>
<html:option value="MAN">男士</html:option>
<html:option value="WOMEN">女士</html:option>  
</html:select>    		      	
	  </td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">型号 ：</div></td>
      <td width="75%"> <html:text property="model" size="35" maxlength="30"/></td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">重量 ：</div></td>
      <td width="75%"> <html:text property="weight" size="10" maxlength="10" onkeypress="javascript:InputLongNumberCheck()"/>克</td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%"> <div align="right">购买说明 ：</div></td>
      <td width="75%"> <html:text property="buyexplain" size="35" maxlength="30"/></td>
    </tr>
	<tr bgcolor="f5f5f5"> 
      <td width="25%" valign="top"> <div align="right">产品简介<font color="#FF0000">*</font> ：</div></td>
      <td width="75%"><html:textarea property="description" cols="80" rows="23"></html:textarea></td>      
	</tr>
    <tr bgcolor="f5f5f5"> 
      <td colspan="2"> <div align="center"> 
          <input type="button" name="edit" value=" 确 认 " class="frm_btn" onClick="javascript:SureSubmit(this.form)">
            <input type="button" name="Button" value=" 返 回 " class="frm_btn" onclick="javascript:history.back()">
        </div></td>
    </tr>
  </table>
</html:form>
<br>
</body>
</html>

////////////////////////////

[jane123456789]

代码那么多，最讨厌看代码的。。有心无力。。帮不了楼主

[juyuquan1986]

还是 debug 吧

[xusheng1018]

java.lang.NullPointerException
com.myboxcs.web.action.product.ProductManageAction.edit(ProductManageAction.java:152)

找这行啊，NullPointerException 又不是什么很难解决的异常，debug跟踪一下，仔细检查下，应该可以找出来的~

[wlt0727]

打个断点一步一步调试吧，代码这么多没办法结贴的

[zengjava]

引用 3 楼 wlt0727 的回复:

打个断点一步一步调试吧，代码这么多没办法结贴的

应该就只有这段 和jsp有问题的
/**
*
产品修改
*/
public ActionForward edit(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
ProductForm formbean=(ProductForm) form;
ProductInfo product = productInfoService.find(ProductInfo.class, formbean.getProductid());
product.setName(formbean.getName());
product.setBaseprice(formbean.getBaseprice());
product.setSellprice(formbean.getSellprice());
product.setMarketprice(formbean.getMarketprice());
if(formbean.getBrandid()!=null && "".equals(formbean.getBrandid().trim())){
product.setBrand(new Brand(formbean.getBrandid()));
}
product.setDescription(formbean.getDescription());
product.setBuyexplain(formbean.getBuyexplain());
product.setCode(formbean.getCode());
product.setModel(formbean.getModel());
product.setSexrequest(Sex.valueOf(formbean.getSex()));
product.setWeight(formbean.getWeight());
product.setType(new productType(formbean.getTypeid()));
productInfoService.update(product);
request.setAttribute("massage", "修改成功");
return mapping.findForward("massage");
}
}

[tuo_bing]

ProductForm formbean=(ProductForm) form;
测试是否取到值 ：
System.out.println("-------------" + formbean.getName());
......

ProductInfo product = productInfoService.find(ProductInfo.class, formbean.getProductid());
这句话的意思是获取 ProductInfo 对象吧 ？
下面为什么还要 product.set...()

if(formbean.getBrandid()!=null && "".equals(formbean.getBrandid().trim())){
}
&& 后面的条件是不是还需要一个 ”非“

随便看了下，你自己慢慢调吧 。。。

[aSysBang]

com.myboxcs.web.action.product.ProductManageAction.edit(ProductManageAction.java:152)
看看这个文件的152行

[zengjava]

引用 10 楼 xusheng1018 的回复:

java.lang.NullPointerException
com.myboxcs.web.action.product.ProductManageAction.edit(ProductManageAction.java:152)

找这行啊，NullPointerException 又不是什么很难解决的异常，debug跟踪一下，仔细检查下，应该可以找出来的~

问题出在这里

/**
	 * 
	 产品修改
	 */
	public ActionForward edit(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		ProductForm formbean=(ProductForm) form;
		ProductInfo product = productInfoService.find(ProductInfo.class, formbean.getProductid());
        /*product.setName(formbean.getName());
		product.setBaseprice(formbean.getBaseprice());
		product.setSellprice(formbean.getSellprice());
		product.setMarketprice(formbean.getMarketprice());
		if(formbean.getBrandid()!=null && "".equals(formbean.getBrandid().trim())){
			product.setBrand(new Brand(formbean.getBrandid()));
		}
		product.setDescription(formbean.getDescription());
		product.setBuyexplain(formbean.getBuyexplain());
		product.setCode(formbean.getCode());
		product.setModel(formbean.getModel());
		product.setSexrequest(Sex.valueOf(formbean.getSex()));
		product.setWeight(formbean.getWeight());
		product.setType(new productType(32));
                productInfoService.update(product);*/
		System.out.println(product); 我直接打印product 发现是为空的所以product.set 时候就开始报错
		request.setAttribute("massage", "修改成功");
		return mapping.findForward("massage");
	}	

但是很疑惑 ProductInfo product = productInfoService.find(ProductInfo.class, formbean.getProductid()); 这样不就获取到了 当前需要修改的对象了吗？

[LuffySY]

debug的时候step into 进find方法里面看看

[Z_FEI]

设断点测试下，出现异常时，停留在哪里，这对那里好好检查下，就能很快解决的！

[Fairy_dy]

设个断点,这个很容易，我们没有环境，不好直接调试

[beckhamcat1]

你update的时候对象没有设置id

[beckhamcat1]

ProductInfo product = productInfoService.find(ProductInfo.class, 2);
没看见。。。不好意思。

[哀]

debug下就好了，如果不想debug
注意这条错误信息
com.myboxcs.web.action.product.ProductManageAction.edit(ProductManageAction.java:152)

ProductManageAction.java的第152行有错误，去检查这里是哪个值为null了，然后这个值又是用什么来得到的，反着想，找到源头是哪个没有取到值。