错误:找不到操作或结果没有为操作操作定义结果.部分和结果{“col1":“col1"，“col2":“col2"}

Returning json result type is not needed if you build the JSONObject manually. You can return text as stream result then convert a string to JSON if needed.

struts.xml:

<package name="default" extends="struts-default">
  <action name="part" class="action.PartAction" method="finder">    
    <result type="stream">
      <param name="contentType">text/html</param>
      <param name="inputName">stream</param>
    </result>
  </action>
</package>

行动:

public class PartAction extends ActionSupport {

  public class SearchResult {
    private String col1;
    private String col2;

    public String getCol1() {
      return col1;
    }

    public void setCol1(String col1) {
      this.col1 = col1;
    }

    public String getCol2() {
      return col2;
    }

    public void setCol2(String col2) {
      this.col2 = col2;
    }

    public SearchResult(String col1, String col2) {
      this.col1 = col1;
      this.col2 = col2;
    }
  }

  private InputStream stream;

  //getter here
  public InputStream getStream() {
    return stream;
  }

  private List<SearchResult> findList = new ArrayList<>();

  public List<SearchResult> getFindList() {
    return findList;
  }

  public void setFindList(List<SearchResult> findList) {
    this.findList = findList;
  }

  private String list() {
    JSONObject jo = new JSONObject();
    try {
      for (SearchResult part : findList) {
        jo.put("col1", part.getCol1());
        jo.put("col2", part.getCol2());
      }
      System.out.println("--------->:"+jo.toString());
    } catch (Exception e) {
      e.printStackTrace();
      System.out.println(e.getMessage());
    }
    return jo.toString();
  }

  @Action(value="part", results = {
    @Result(name="stream", type="stream", params = {"contentType", "text/html", "inputName", "stream"}),
    @Result(name="stream2", type="stream", params = {"contentType", "application/json", "inputName", "stream"}),
    @Result(name="json", type="json", params={"root", "findList"})
  })
  public String finder() {
    findList.add(new SearchResult("val1", "val2"));
    stream = new ByteArrayInputStream(list().getBytes());
    return "stream2";
  }
}

我已经使用结果类型和内容类型放置了不同的结果，以更好地描述这个想法.您可以返回这些结果中的任何一个，并返回字符串化或未字符串化的 JSON 对象.字符串化版本需要解析返回的数据以获取 JSON 对象.您还可以选择哪种结果类型可以更好地序列化以满足您的需求，但我的目标是表明，如果您需要序列化简单对象，则不需要 json 插件即可使其正常工作.