以操作插件为例

public class DownlaodContract extends AbstractOperationServicePlugIn implements Plugin {
    @Override
    public void onPreparePropertys(PreparePropertysEventArgs e) {
        super.onPreparePropertys(e);
        e.getFieldKeys().add("yfsw_htzhuangtai");
    }

    @Override
    public void onAddValidators(AddValidatorsEventArgs e) {
        e.addValidator(new AbstractValidator() {
            public void validate() {
                for (ExtendedDataEntity rowDataEntity : this.getDataEntities()) {
                    DynamicObject dataEntity = rowDataEntity.getDataEntity();
                    String zhuangtai = dataEntity.getString("yfsw_htzhuangtai");
                    if(zhuangtai != "B" || zhuangtai != "C"){
                        this.addErrorMessage(rowDataEntity,"合同未签署或已作废");
                    }
                }
            }
        });
    }

    @Override
    public void afterExecuteOperationTransaction(AfterOperationArgs e) {
        String privapi_url = "";
        String documentId = "";
        String url = privapi_url + "/document/download?documentId="+documentId;
        super.afterExecuteOperationTransaction(e);
        CloseableHttpClient httpClient = HttpClients.createDefault();
        StringBuilder entityStringBuilder = null;
        try {
            HttpGet get = new HttpGet(url);
            CloseableHttpResponse httpResponse = null;
            httpResponse = httpClient.execute(get);
            try {
                HttpEntity entity = httpResponse.getEntity();
                entityStringBuilder = new StringBuilder();
                if (null != entity) {
                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(httpResponse.getEntity().getContent(), "UTF-8"), 8 * 1024);
                    String line = null;
                    while ((line = bufferedReader.readLine()) != null) {
                        entityStringBuilder.append(line + "/n");
                    }
                }
            } finally {
                httpResponse.close();
            }
        } catch (Exception a) {
            a.printStackTrace();
        } finally {
            try {
                if (httpClient != null) {
                    httpClient.close();
                }
            } catch (IOException a) {
                a.printStackTrace();
            }
        }
    }
}