java Spring 表单命令可以是 Map 吗？

Can a Spring form command be a Map?

提问by Steve Kuo

Can a Spring form command be a Map? I made my command a Map by extending HashMap and referenced the properties using the ['property']notation but it didn't work.

Spring 表单命令可以是 Map 吗？我通过扩展 HashMap 使我的命令成为 Map 并使用['property']符号引用属性，但它不起作用。

Command:

命令：

public class MyCommand extends HashMap<String, Object> {
}

HTML form:

HTML表格：

Name: <form:input path="['name']" />

Results in the error:

结果报错：

org.springframework.beans.NotReadablePropertyException: Invalid property '[name]' of bean class [com.me.MyCommand]: Bean property '[name]' is not readable or has an invalid getter method: Does the return type of the getter match the parameter type of the setter?

Is this not allowed or do I have incorrect syntax?

这是不允许的还是我的语法不正确？

回答by cletus

Springn MVC commands need to use JavaBeans naming conventins (ie getXXX() and setXXX()) so no you can't use a map for that.

Springn MVC 命令需要使用 JavaBeans 命名约定（即 getXXX() 和 setXXX()），因此您不能为此使用映射。

One alternative is to have a bean with a single Map property ie:

一种替代方法是让 bean 具有单个 Map 属性，即：

public class MyCommand {
  private final Map<String, Object> properties = new HashMap<String, Object>();

  public Map<String, Object> getProperties() { return properties; }
  // setter optional
}

Then you can do something like this (not 100% sure on the syntax but it is possible):

然后你可以做这样的事情（不是 100% 确定语法，但它是可能的）：

Name: <form:input path="properties['name']" />

回答by Marius Jeskulke

Combining the answer of cletus and dbell I could actually make it work and would like to share the solution with you (including binding of values when submitting the form, a flaw reported for cletus solution)

结合 cletus 和 dbell 的答案，我实际上可以使它工作，并希望与您分享解决方案（包括提交表单时的值绑定，cletus 解决方案报告的缺陷）

You cannot use directly a map as command, however have another domain object that needs to wrap a lazy map

您不能直接使用地图作为命令，但是有另一个需要包装惰性地图的域对象

public class SettingsInformation {

    private Map<String, SettingsValue> settingsMap= MapUtils.lazyMap(new HashMap<String, SettingsValue>(),FactoryUtils.instantiateFactory(SettingsValue.class));

    public Map<String, SettingsValue> getSettingsMap() {
        return settingsMap;
    }

    public void setSettingsMap(Map<String, SettingsValue > settingsMap) {
        this.settingsMap = settingsMap;
    }

}

SettingsValue is a class that actually wraps the value.

SettingsValue 是一个实际包装值的类。

public class SettingsValue {

private String value;

public SettingsValue(String value) {
    this.value = value;
}


public SettingsValue() {

}

public String getValue() {

    return value;
}

public void setValue(String propertyValue) {

    this.value = propertyValue;
}

The controller method providing the model looks like this:

提供模型的控制器方法如下所示：

    @RequestMapping(value="/settings", method=RequestMethod.GET)
public ModelAndView showSettings() {

    ModelAndView modelAndView = new ModelAndView("settings");

    SettingsDTO settingsDTO = settingsService.getSettings();
    Map<String, String> settings = settingsDTO.getSettings();

    SettingsInformation settingsInformation = new SettingsInformation();

    for (Entry<String, String> settingsEntry : settings.entrySet()) {
        SettingsValue settingsValue = new SettingsValue(settingsEntry.getValue());
        settingsInformation.getSettingsMap().put(settingsEntry.getKey(), settingsValue);
    }

    modelAndView.addObject("settings", settingsInformation);

    return modelAndView;
}

Your form should look like this

您的表单应如下所示

<form:form action="${actionUrl}" commandName="settings">
        <form:input path="settingsMap['exampleKey'].value"/>
        <input type="submit" value="<fmt:message key="settings.save"/>"/>
</form:form>

The controller method handling form submission works as usual

处理表单提交的控制器方法照常工作

@RequestMapping(value="/settings", method=RequestMethod.POST)
public ModelAndView updateSettings(@ModelAttribute(value="settings") SettingsInformation settings) {
[...]
}

I verified the SettingsInformation bean is actually filled with the values in the form.

我验证了 SettingsInformation bean 实际上填充了表单中的值。

Thanks for helping me with this one; If you have any questions feel free to ask.

谢谢你帮我解决这个问题；如果您有任何问题随时问。

回答by Deprecated Darren

Ok i have a solution that works for me i use MapUtils.lazyMap

好的，我有一个适合我的解决方案，我使用 MapUtils.lazyMap

//My Root domain

//我的根域

    public class StandardDomain {

        private Map<String, AnotherDomainObj> templateMap= MapUtils.lazyMap(new HashMap<String, AnotherDomainObj>(),FactoryUtils.instantiateFactory(AnotherDomainObj.class));

        public Map<String, AnotherDomainObj> getTemplateContentMap() {
            return templateMap;
        }

        public void setTemplateContentMap(Map<String, AnotherDomainObj > templateMap) {
            templateMap = templateMap;
        }

    }

//my second domain

//我的第二个域

public class AnotherDomainObj  {

    String propertyValue="";

        public String getPropertyValue() {
           return propertyValue;
        }

        public void setPropertyValue(String propertyValue) {
           this.propertyValue = propertyValue;
     }



}

//In my JSP

//在我的JSP中

<input type="text" value="testthis" name="templateMap['keyName'].propertyValue"/>

回答by Deprecated Darren

Yes it can but... You need to reference it as <form:input path="name[index].key|value"/> e.g.

是的，它可以，但是...您需要将其引用为<form:input path="name[index].key|value"/> 例如

<form:input path="name[0].value"/>

<form:input path="name[0].value"/>