为应用程序/Java 脚本启用参数上载 | Teradata AppCenter - 1.9 - 为应用程序和 Java 脚本启用上载参数 - Teradata AppCenter

Teradata® AppCenter 用户指南

prodname
Teradata AppCenter
vrm_release
1.9
created_date
2019 年 12 月
category
用户指南
featnum
B035-1111-119K-CHS
"" 用户、管理员

要为应用程序或 Java 脚本启用参数上载,请执行以下操作:

  1. 在应用程序或脚本代码中,将参数文件读入内存中。
    例如,如果参数名称为 ‘param’,则文件将位于此目录:/data/parameters/job_id/param
  2. 转换文件以反映所需的查询。
    例如,如果您有 SQL 查询 select * from table where column1 in (${param}),则将 ${param} 替换为上载的文件中的值列表。上载的文件将具有以下格式:

    value1

    value2

    value3

    最终 SQL 查询将是:select * from table where column1 in (‘value1’, ‘value2’, ‘value3’)

    以下是用于启用参数上载的示例 JAVA 代码:

    public class SampleApp
    {
        private static final String PARAMETER_VOLUME_MOUNT_PATH = "/data/parameters/";
    
        public static void main( String[] args ) throws Exception
        {
            String query1 = "select * from cfilter_demo where col1_item1 in (${param});";
    
            Try (DefaultAppCenterClient client = new DefaultAppCenterClient()) {
                client.log(LogLevel.INFO, "Replacing query parameters...");
                String query = replaceWithConfig(client, query1, "param");
                    
                client.log(LogLevel.INFO, "executing query:" + query);
                InputStream resultStream = client.streamResultsFromQuery(query);
                
                client.log(LogLevel.INFO, "Caching result...");
                client.cacheResult(resultStream, "application/json");
                
            } catch (Exception e) {
                e.printStackTrace();
                System.exit(1);
            }
        }
    
        private static String getParamValueFromFile(DefaultAppCenterClient client, String configParamName) throws IOException {
            String paramFile = PARAMETER_VOLUME_MOUNT_PATH + client.getAppContext().getJobId() + "/" +
                    configParamName;
            StringBuilder configParamValue = new StringBuilder();
            boolean isFirst = true;
            try (BufferedReader br = new BufferedReader(new FileReader(paramFile))) {
                for (String line; (line = br.readLine()) != null; ) {
                    if (!isFirst) {
                        configParamValue.append(",");
                    } else {
                       isFirst = false;
                    }
                    configParamValue.append("'").append(line).append("'");
                }
            }
            return configParamValue.toString();
        }
        
        private static String replaceWithConfig(DefaultAppCenterClient client, String query, String paramName) throws IOException {
            String paramValue = getParamValueFromFile(client, paramName);
            query = query.replace("${" + paramName + "}", paramValue);
            return query;
        }