Karate集成Cassandra：如何从Feature文件传查询与配置至Java数据库工具

你现有的Java Cassandra数据库工具类依赖本地属性文件读取配置，查询语句硬编码，无法在Karate框架中灵活复用。以下是具体改造方案和代码：

原工具类代码 #

package Utilities;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.Session;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;


public class DatabaseConnectionUtils {
    public static Properties readPropertiesFile(String fileName) throws IOException {
        FileInputStream fis = null;
        Properties prop = null;
        try {
            fis = new FileInputStream(fileName);
            prop = new Properties();
            prop.load(fis);
        } catch(FileNotFoundException fnfe) {
            fnfe.printStackTrace();
        } finally {
            fis.close();
        }
        return prop;
    }

    public static void connect(String serverIP, Integer port, String keyspace, String username, String password) {
        Cluster cluster;
        Session session;
        Cluster.Builder b = Cluster.builder().addContactPoint(serverIP);
        if (port != null) {
            b.withPort(port).withCredentials(username,password);
        }
        cluster = b.build();
        session = cluster.connect(keyspace);

        String cqlStatement = "select * from partner_configuration where partnerid='15918' allow filtering;";
        for (Row row : session.execute(cqlStatement)) {
            System.out.println(row.toString());
        }
        session.close();
    }

    public static void main(String[] args) throws IOException {

        Properties prop = readPropertiesFile("C:\\NMS-Framework\\untitled\\src\\test\\resources\\DB-Credentials.properties");
        String address=prop.getProperty("ServerIP");
        int port= Integer.parseInt(prop.getProperty("port"));
        String keyspace=prop.getProperty("keyspace");
        String username=prop.getProperty("username");
        String password= prop.getProperty("password");

        connect(address,port,keyspace,username,password);
    }
}

改造方案与代码 #

关键改造说明 #

• 拆分连接与查询逻辑，让工具类支持传入任意CQL语句
• 移除本地属性文件依赖，所有数据库配置通过参数传入
• 用try-with-resources自动管理Cluster和Session，避免连接泄漏
• 返回List<Map<String, Object>>格式的结果，适配Karate的断言和处理逻辑

改造后的工具类 #

package Utilities;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.ColumnDefinitions;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class DatabaseConnectionUtils {

    // 对外暴露的核心方法：传入配置和CQL，返回结构化查询结果
    public static List<Map<String, Object>> executeQuery(String serverIP, Integer port, String keyspace, 
                                                        String username, String password, String cqlStatement) {
        List<Map<String, Object>> queryResults = new ArrayList<>();
        
        // try-with-resources自动关闭Cluster和Session，无需手动处理
        try (Cluster cluster = buildCluster(serverIP, port, username, password);
             Session session = cluster.connect(keyspace)) {
            
            // 遍历查询结果，转成Karate友好的Map结构
            for (Row row : session.execute(cqlStatement)) {
                Map<String, Object> rowData = new HashMap<>();
                ColumnDefinitions columns = row.getColumnDefinitions();
                for (ColumnDefinitions.Definition colDef : columns) {
                    rowData.put(colDef.getName(), row.getObject(colDef.getName()));
                }
                queryResults.add(rowData);
            }
        } catch (Exception e) {
            // 抛出RuntimeException让Karate捕获，便于调试
            throw new RuntimeException("Cassandra查询失败: " + e.getMessage(), e);
        }
        
        return queryResults;
    }

    // 封装Cluster构建逻辑，简化主方法代码
    private static Cluster buildCluster(String serverIP, Integer port, String username, String password) {
        Cluster.Builder builder = Cluster.builder().addContactPoint(serverIP);
        
        if (port != null) {
            builder.withPort(port);
        }
        if (username != null && password != null) {
            builder.withCredentials(username, password);
        }
        
        return builder.build();
    }
}

Karate Feature文件调用示例 #

在Karate里可以直接通过Java.type调用改造后的工具类，灵活传入配置和查询语句：

Feature: Cassandra数据库查询测试
  Background:
    # 引入工具类
    * def DbUtils = Java.type('Utilities.DatabaseConnectionUtils')
    # 定义数据库配置（可以放在config文件里全局复用）
    * def dbConfig = { serverIP: '192.168.1.100', port: 9042, keyspace: 'your_keyspace', username: 'test_user', password: 'test_pass' }

  Scenario: 执行自定义CQL查询
    # 传入要执行的查询语句
    * def cqlQuery = "select * from partner_configuration where partnerid='15918' allow filtering;"
    # 调用工具类执行查询
    * def results = DbUtils.executeQuery(dbConfig.serverIP, dbConfig.port, dbConfig.keyspace, dbConfig.username, dbConfig.password, cqlQuery)
    # 打印结果（调试用）
    * print "查询结果: ", results
    # 对结果做断言
    * match results.size() == 1
    * match results[0].partnerid == '15918'

额外说明 #

• 数据库配置可以放在Karate的全局配置文件（比如karate-config.js）里，实现跨Feature复用
• 返回的List<Map>结构完全兼容Karate的所有断言语法，不用额外转换
• 异常处理逻辑会把错误信息抛出，Karate会在测试报告里展示详细堆栈，方便定位问题

内容的提问来源于stack exchange，提问作者user3048388