Question

我遇到了许多例外情况，我发现这些例外对我的问题没有帮助，

这里是他们

Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"
java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"
org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"
org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"
org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"
org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"
org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"
org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"

这是我的动作类，它返回JSON

public class GetTagsAction extends ActionSupport{       
    public String execute(){

        Gson gson = new Gson();
        String tags = gson.toJson(audioTaggingService.findTagsByName(q));
        System.out.println(tags);

        return Action.SUCCESS;
    }

    public String getQ() {
        return q;
    }

    public void setQ(String q) {
        this.q = q;
    }

    public AudioTaggingService getAudioTaggingService() {
        return audioTaggingService;
    }

    public void setAudioTaggingService(AudioTaggingService audioTaggingService) {
        this.audioTaggingService = audioTaggingService;
    }

    public String getTags() {
        return tags;
    }

    public void setTags(String tags) {
        this.tags = tags;
    }

    private String q;
    private AudioTaggingService audioTaggingService;
    private String tags;
}

这是包

<package name="default" namespace="/" extends="json-default">
    <!--  Get AJAX Related Actions -->
    <action name="tags" class="tags">
        <result type="json" />
    </action>
</package>

我正在使用Struts2-JSON-plugin

Answer 1

错误是因为插件试图转换整个对象图，看起来插件试图通过audioTaggingService转换数据库层。您需要在struts XML中指定“root”参数

<action name="tags" class="tags">
    <result type="json">
      <param name="root">tags</param>
    </result>
</action>

并在您的操作中提供getTags（）方法。

但是，我不确定这会有所帮助。我不确定当你尝试JSON-ify已经包含JSON数据的String时会发生什么。

Answer 2

您需要在xml中编辑以下行

 <action name="tags" class="tags">

属性class正在寻找详细的类名com.your.package.YourAction

详细here

Answer 3

如果其中一个JSON数据为空，有时会出现此错误，它在转换时不会出错，但在处理数据时会出错。

Struts2 JSON Writer发送JSON响应时的异常

3 个答案: