2

私のエンティティクラス:

import java.util.ArrayList;


public class Test {
    private String name;
    private String description;
    private ArrayList<String> countries;

    public Test() {

    }

    public String getName() {
        return name;
    }

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

    public String getDescription() {
        return description;
    }

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

    public ArrayList<String> getCountries() {
        return countries;
    }

    public void setCountries(ArrayList<String> countries) {
        this.countries = countries;
    }
}

送信しようとしている JSON:

{"countries": ["CA", "SG"], "description":"whee", "name": "foo"}

エラー：

2345447 [http-bio-8080-exec-1] ERROR freemarker.runtime  - Method public java.lang.String org.apache.commons.lang.exception.NestableRuntimeException.getMessage(int) threw an exception when invoked on net.sf.json.JSONException: Error while setting property=countries type interface java.util.List

Method public java.lang.String org.apache.commons.lang.exception.NestableRuntimeException.getMessage(int) threw an exception when invoked on net.sf.json.JSONException: Error while setting property=countries type interface java.util.List
The problematic instruction:
----------
==> ${msgs[0][0]} [on line 76, column 25 in org/apache/struts2/dispatcher/error.ftl]
----------

Java backtrace for programmers:
----------
freemarker.template.TemplateModelException: Method public java.lang.String org.apache.commons.lang.exception.NestableRuntimeException.getMessage(int) threw an exception when invoked on net.sf.json.JSONException: Error while setting property=countries type interface java.util.List
    at freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:130)
    at freemarker.ext.beans.SimpleMethodModel.get(SimpleMethodModel.java:138)
    at freemarker.core.DynamicKeyName.dealWithNumericalKey(DynamicKeyName.java:111)
    at freemarker.core.DynamicKeyName._getAsTemplateModel(DynamicKeyName.java:90)
    at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
    at freemarker.core.Expression.getStringValue(Expression.java:93)
    at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
    at freemarker.core.Environment.visit(Environment.java:210)
    at freemarker.core.MixedContent.accept(MixedContent.java:92)
    at freemarker.core.Environment.visit(Environment.java:210)
    at freemarker.core.IfBlock.accept(IfBlock.java:82)
    at freemarker.core.Environment.visit(Environment.java:210)
    at freemarker.core.IfBlock.accept(IfBlock.java:82)
    at freemarker.core.Environment.visit(Environment.java:210)
    at freemarker.core.MixedContent.accept(MixedContent.java:92)
    at freemarker.core.Environment.visit(Environment.java:210)
    at freemarker.core.Environment.process(Environment.java:190)
    at freemarker.template.Template.process(Template.java:237)
    at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:797)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:519)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:851)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:278)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:300)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:680)
Caused by: java.lang.NullPointerException
    at freemarker.ext.beans.SimpleMemberModel.unwrapArguments(SimpleMemberModel.java:85)
    at freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:106)
    ... 37 more

「国」作業を渡そうとせずに「名前」と「説明」を設定すると、値が正常にマッピングされます。

次の XML を使用しても機能します。

<com.foo.bar.entity.Test>
<countries>
<string>SG</string>
</countries>
<description>testt</description>
</com.foo.bar.entity.Test>

アップデート：

List を String[] に変更すると機能します。私はこれに耐えることができますが、Struts/rest-plugin/json-plugin に、配列ではなくリストを非常に好むことを示すことができるかどうかを知っている人はいますか?

4

1 に答える 1

0

これをやってみてください 

private List<String> countries;

おそらく、jsonパーサーがList<>オブジェクトを送信し、varがタイプの場合にエラーが発生しますArrayList<>

パーサーが設定するインスタンスの型がわからないので、常に実装の代わりにインターフェイスを使用してください。

于 2012-10-11T03:02:21.457 に答える