使用JSON帖子嵌套的对象了Spring MVC控制器 [英] Post Nested Object to Spring MVC controller using JSON
问题描述
我有一个像这样定义的POST处理程序控制器：
I have a controller with the POST handler defined like so:
@RequestMapping(value="/ajax/saveVendor.do", method = RequestMethod.POST)
public @ResponseBody AjaxResponse saveVendor( @Valid UIVendor vendor,
BindingResult result,
Locale currentLocale )
在UIVendor对象，JSON格式查看时，是这样的：
The UIVendor object, when viewed in JSON format, looks like:
var vendor =
{
vendorId: 123,
vendorName: "ABC Company",
emails : [
{ emailAddress: "abc123@abc.com", flags: 2 },
{ emailAddress: "xyz@abc.com", flags: 3 }
]
}
该UIVendor bean有一个名为ArrayList类型的电子邮件字段中，适当的getter和setter方法（getEmails / setEmails）。该NotificationEmail对象具有适当的公共的setter / getter方法为好。
The UIVendor bean has a field called "Emails" of type ArrayList, with appropriate setters and getters (getEmails/setEmails). The NotificationEmail object has the appropriate public setters/getters as well.
当我尝试使用下面的code发布对象：
When I try to post the object using the following code:
$.post("ajax/saveVendor.do", $.param(vendor), saveEntityCallback, "json" );
我得到的日志中此错误：
I get this error in the logs:
Invalid property 'emails[0][emailAddress]' of bean class [beans.UIVendor]: Property referenced in indexed property path 'emails[0][emailAddress]' is neither an array nor a List nor a Map; returned value was [abc123@abc.com]
我如何正确地发布这样一个嵌套的对象一个春天控制器，而且它正确反序列化到合适的对象结构。
How do I correctly post a nested object like this to a Spring controller and have it correctly deserialize into the appropriate object structure.
更新 每Bohzo的要求，这里是UIVendor类的内容。这个类封装了一个web服务生成的bean类，露出VendorAttributes作为单独的领域：
UPDATE Per Bohzo's request, here is the content of the UIVendor class. This class wraps a web-service-generated bean class, exposing the VendorAttributes as individual fields:
package com.mycompany.beans;
import java.util.*;
import org.apache.commons.lang.*;
import com.mycompany.domain.Vendor;
import com.mycompany.domain.VendorAttributes;
import org.apache.commons.logging.*;
import org.codehaus.jackson.annotate.JsonIgnore;
public class UIVendor
{
private final Log logger = LogFactory.getLog( this.getClass() );
private Vendor vendor;
private boolean ftpFlag;
private String ftpHost;
private String ftpPath;
private String ftpUser;
private String ftpPassword;
private List<UINotificationEmail> emails = null;
public UIVendor() { this( new Vendor() ); }
public UIVendor( Vendor vendor )
{
this.vendor = vendor;
loadVendorAttributes();
}
private void loadVendorAttributes()
{
this.ftpFlag = false;
this.ftpHost = this.ftpPassword = this.ftpPath = this.ftpUser = "";
this.emails = null;
for ( VendorAttributes a : this.vendor.getVendorAttributes() )
{
String key = a.getVendorFakey();
String value = a.getVendorFaValue();
int flags = a.getFlags();
if ( StringUtils.isBlank(key) || StringUtils.isBlank(value) ) continue;
if ( key.equals( "ftpFlag" ) )
{
this.ftpFlag = BooleanUtils.toBoolean( value );
}
else if ( key.equals( "ftpHost" ) )
{
this.ftpHost = value;
}
else if ( key.equals("ftpPath") )
{
this.ftpPath = value;
}
else if ( key.equals("ftpUser") )
{
this.ftpUser = value;
}
else if ( key.equals("ftpPassword") )
{
this.ftpPassword = value;
}
else if ( key.equals("email") )
{
UINotificationEmail email = new UINotificationEmail(value, flags);
this.getEmails().add( email );
}
}
}
private void saveVendorAttributes()
{
int id = this.vendor.getVendorId();
List<VendorAttributes> attrs = this.vendor.getVendorAttributes();
attrs.clear();
if ( this.ftpFlag )
{
VendorAttributes flag = new VendorAttributes();
flag.setVendorId( id );
flag.setStatus( "A" );
flag.setVendorFakey( "ftpFlag" );
flag.setVendorFaValue( BooleanUtils.toStringTrueFalse( this.ftpFlag ) );
attrs.add( flag );
if ( StringUtils.isNotBlank( this.ftpHost ) )
{
VendorAttributes host = new VendorAttributes();
host.setVendorId( id );
host.setStatus( "A" );
host.setVendorFakey( "ftpHost" );
host.setVendorFaValue( this.ftpHost );
attrs.add( host );
if ( StringUtils.isNotBlank( this.ftpPath ) )
{
VendorAttributes path = new VendorAttributes();
path.setVendorId( id );
path.setStatus( "A" );
path.setVendorFakey( "ftpPath" );
path.setVendorFaValue( this.ftpPath );
attrs.add( path );
}
if ( StringUtils.isNotBlank( this.ftpUser ) )
{
VendorAttributes user = new VendorAttributes();
user.setVendorId( id );
user.setStatus( "A" );
user.setVendorFakey( "ftpUser" );
user.setVendorFaValue( this.ftpUser );
attrs.add( user );
}
if ( StringUtils.isNotBlank( this.ftpPassword ) )
{
VendorAttributes password = new VendorAttributes();
password.setVendorId( id );
password.setStatus( "A" );
password.setVendorFakey( "ftpPassword" );
password.setVendorFaValue( this.ftpPassword );
attrs.add( password );
}
}
}
for ( UINotificationEmail e : this.getEmails() )
{
logger.debug("Adding email " + e );
VendorAttributes email = new VendorAttributes();
email.setStatus( "A" );
email.setVendorFakey( "email" );
email.setVendorFaValue( e.getEmailAddress() );
email.setFlags( e.getFlags() );
email.setVendorId( id );
attrs.add( email );
}
}
@JsonIgnore
public Vendor getVendor()
{
saveVendorAttributes();
return this.vendor;
}
public int getVendorId()
{
return this.vendor.getVendorId();
}
public void setVendorId( int vendorId )
{
this.vendor.setVendorId( vendorId );
}
public String getVendorType()
{
return this.vendor.getVendorType();
}
public void setVendorType( String vendorType )
{
this.vendor.setVendorType( vendorType );
}
public String getVendorName()
{
return this.vendor.getVendorName();
}
public void setVendorName( String vendorName )
{
this.vendor.setVendorName( vendorName );
}
public String getStatus()
{
return this.vendor.getStatus();
}
public void setStatus( String status )
{
this.vendor.setStatus( status );
}
public boolean isFtpFlag()
{
return this.ftpFlag;
}
public void setFtpFlag( boolean ftpFlag )
{
this.ftpFlag = ftpFlag;
}
public String getFtpHost()
{
return this.ftpHost;
}
public void setFtpHost( String ftpHost )
{
this.ftpHost = ftpHost;
}
public String getFtpPath()
{
return this.ftpPath;
}
public void setFtpPath( String ftpPath )
{
this.ftpPath = ftpPath;
}
public String getFtpUser()
{
return this.ftpUser;
}
public void setFtpUser( String ftpUser )
{
this.ftpUser = ftpUser;
}
public String getFtpPassword()
{
return this.ftpPassword;
}
public void setFtpPassword( String ftpPassword )
{
this.ftpPassword = ftpPassword;
}
public List<UINotificationEmail> getEmails()
{
if ( this.emails == null )
{
this.emails = new ArrayList<UINotificationEmail>();
}
return emails;
}
public void setEmails(List<UINotificationEmail> emails)
{
this.emails = emails;
}
}
更新2 下面是从杰克逊的输出：
UPDATE 2 Here's the output from Jackson.:
{
"vendorName":"MAIL",
"vendorId":45,
"emails":
[
{
"emailAddress":"dfg",
"success":false,
"failure":false,
"flags":0
}
],
"vendorType":"DFG",
"ftpFlag":true,
"ftpHost":"kdsfjng",
"ftpPath":"dsfg",
"ftpUser":"sdfg",
"ftpPassword":"sdfg",
"status":"A"
}
这里是我回帖子上的对象的结构：
And here is the structure of the object I'm returning on the POST:
{
"vendorId":"45",
"vendorName":"MAIL",
"vendorType":"DFG",
"ftpFlag":true,
"ftpHost":"kdsfjng",
"ftpUser":"sdfg",
"ftpPath":"dsfg",
"ftpPassword":"sdfg",
"status":"A",
"emails":
[
{
"success":"false",
"failure":"false",
"emailAddress":"dfg"
},
{
"success":"true",
"failure":"true",
"emailAddress":"pfc@sj.org"
}
]
}
我试着使用JSON库从www.json.org以及序列化，其结果是什么你在上面看到。然而，当我发布这些数据，都在传递给控制器UIVendor对象的字段为空（虽然对象不是）。
I've tried serializing using the JSON library from www.json.org as well, and the result is exactly what you see above. However, when I post that data, all of the fields in the UIVendor object passed to the controller are null (although the object is not).
推荐答案
经过大量的试验和错误，我终于想通了，还有我可以，问题是什么。当使用下面的控制器方法签名：
After much trial and error, I've finally figured out, as well as I can, what the problem is. When using the following controller method signature:
@RequestMapping(value="/ajax/saveVendor.do", method = RequestMethod.POST)
public @ResponseBody AjaxResponse saveVendor( @Valid UIVendor vendor,
BindingResult result,
Locale currentLocale )
客户端脚本必须通过在后的数据对象的字段（通常为应用程序/ x-WWW的形式urlen codeD）格式（即字段=值放大器;场2 =值2）。这样做是在jQuery的是这样的：
The client script has to pass the field in the object in post-data (typically "application/x-www-form-urlencoded") format (i.e., field=value&field2=value2). This is done in jQuery like this:
$.post( "mycontroller.do", $.param(object), callback, "json" )
这工作正常，没有子对象或集合简单的POJO对象，但一旦你介绍显著复杂的对象传递，使用jQuery的符号序列化对象的数据不被Spring的映射逻辑确认：
This works fine for simple POJO objects that don't have child objects or collections, but once you introduce significant complexity to the object being passed, the notation used by jQuery to serialize the object data is not recognized by Spring's mapping logic:
object[0][field]
这是我解决这个问题的方法是改变方法签名控制器：
The way that I solved this problem was to change the method signature in the controller to:
@RequestMapping(value="/ajax/saveVendor.do", method = RequestMethod.POST)
public @ResponseBody AjaxResponse saveVendor( @RequestBody UIVendor vendor,
Locale currentLocale )
和从客户端更改呼叫：
$.ajax(
{
url:"ajax/mycontroller.do",
type: "POST",
data: JSON.stringify( objecdt ),
success: callback,
dataType: "json",
contentType: "application/json"
} );
这需要使用 JSON JavaScript库。这也迫使了的contentType为application / json的，这是一个使用@RequestBody注解时所预计春季和序列化对象，杰克逊可以反序列化到一个有效的对象结构的格式。
This requires the use of the JSON javascript library. It also forces the contentType to "application/json", which is what Spring expects when using the @RequestBody annotation, and serializes the object to a format that Jackson can deserialize into a valid object structure.
唯一的副作用是，现在我要处理的控制器方法在我自己的对象的验证，但是这是比较简单的：
The only side effect is that now I have to handle my own object validation inside of the controller method, but that's relatively simple:
BindingResult result = new BeanPropertyBindingResult( object, "MyObject" );
Validator validator = new MyObjectValidator();
validator.validate( object, result );
如果任何人有任何建议，以改善在这个过程中，我所有的耳朵。
If anyone has any suggestions to improve upon this process, I'm all ears.
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