JPOS Q2中ISORequestListener如何实现特定交易自定义响应

我正尝试将原生JPOS项目迁移至Q2框架，目前遇到一个实现难题：需要在ISORequestListener中为用户指定的特定交易返回自定义响应，其余交易保持自动响应。

当前我的工具会接收JSON消息，其中指定了收单方请求消息的发送字段，以及发卡方需要返回的响应字段，示例如下：

{"messages": [
    {"msgName": "Transaction - 01",
     "acquirer": {
         "delay": 5,
         "out": { //send out these fields in the outgoing request
             "0": "0100",
             "2": "9999999999999999",
             "3": "000000",
             "4": "000000045000",
             "6": "000000045000",
             ...
         },
         "in": {}
     },
     "issuer": {
         "in": {},
         "out": { //Issuer responds with these custom fields for this specific txn, other txns auto-respond
             "0": "0110",
             "39": "05"
         }
     }
    }
]}

以下是我为发卡方配置的Q2相关内容：

<channel-adaptor name="iss-channel" class="org.jpos.q2.iso.ChannelAdaptor" logger="Q2">
<channel class="org.jpos.iso.channel.CSChannel" packager="org.jpos.iso.packager.GenericPackager" logger="Q2">
    <property name="packager-config" value="src/main/resources/iso4.xml" />
    <property name="host" value="10.xxx.xxx.xx" />
    <property name="port" value="9999" />
    <property name="timeout" value="300000" />
</channel>
<in>iss-channel-send</in>
<out>iss-channel-receive</out>
<reconnect-delay>10000</reconnect-delay>
</channel-adaptor>

<mux class="org.jpos.q2.iso.QMUX" logger="Q2" name="iss-mux" realm="acq-realm">
<in>iss-channel-receive</in>
<out>iss-channel-send</out>
<ready>iss-channel.ready</ready>
<request-listener class="AutoResponder"></request-listener>
</mux>

AutoResponder类代码如下：

import org.jpos.core.Configurable;
import org.jpos.core.Configuration;
import org.jpos.core.ConfigurationException;
import org.jpos.iso.ISOMsg;
import org.jpos.iso.ISORequestListener;
import org.jpos.iso.ISOSource;

public class AutoResponder implements ISORequestListener, Configurable {
    private Configuration cfg;

    @Override
    public void setConfiguration(Configuration cfg) throws ConfigurationException {
        this.cfg = cfg;
    }

    @Override
    public boolean process(ISOSource source, ISOMsg m) {
        try {
            ISOMsg r = (ISOMsg) m.clone();
            r.setResponseMTI();
            r.set(39, cfg.get("rc", "00"));
            source.send(r);

        } catch (Exception e) {
            throw new RuntimeException("Could not process message");
        }
        return true;
    }
}

当前配置可实现所有交易的自动响应，但我需要针对QA环境的负面测试，根据用户需求修改部分发卡方响应。请问如何基于Q2的ISORequestListener，为特定交易发送自定义字段，同时保持其余交易自动响应？

此前我的工具通过两个线程（收单方、发卡方各一个）构建请求/响应并调用BaseChannel.send()发送，但不确定如何在Q2的ISORequestListener中实现该逻辑。

1. 新增自定义响应规则存储组件 #

实现一个单例类，用来加载、存储和查询用户指定的交易响应规则，支持从JSON配置中读取数据：

import java.util.HashMap;
import java.util.Map;
import com.fasterxml.jackson.databind.ObjectMapper;

// 对应JSON结构的实体类
class TransactionRule {
    private String msgName;
    private AcquirerConfig acquirer;
    private IssuerConfig issuer;
    // 省略getter/setter

    static class AcquirerConfig {
        private int delay;
        private Map<String, String> out;
        private Map<String, String> in;
        // 省略getter/setter
    }

    static class IssuerConfig {
        private Map<String, String> in;
        private Map<String, String> out;
        // 省略getter/setter
    }
}

public class CustomResponseRepository {
    private static final CustomResponseRepository INSTANCE = new CustomResponseRepository();
    // 用交易唯一标识（如PAN+交易码）作为key，存储对应发卡方响应规则
    private final Map<String, TransactionRule.IssuerConfig> issuerResponseMap = new HashMap<>();

    private CustomResponseRepository() {}

    public static CustomResponseRepository getInstance() {
        return INSTANCE;
    }

    // 加载JSON配置到内存
    public void loadConfig(String jsonContent) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        Map<String, Object> root = mapper.readValue(jsonContent, Map.class);
        for (Object msgObj : (Iterable<?>) root.get("messages")) {
            TransactionRule rule = mapper.convertValue(msgObj, TransactionRule.class);
            // 生成交易唯一标识，可根据业务调整规则
            String key = rule.getAcquirer().getOut().get("2") + "_" + rule.getAcquirer().getOut().get("3");
            issuerResponseMap.put(key, rule.getIssuer());
        }
    }

    // 根据请求消息查询自定义响应规则
    public TransactionRule.IssuerConfig findIssuerResponse(ISOMsg request) throws Exception {
        String pan = request.getString(2);
        String procCode = request.getString(3);
        String key = pan + "_" + procCode;
        return issuerResponseMap.get(key);
    }
}

2. 修改AutoResponder类，加入规则匹配逻辑 #

在原有自动响应逻辑基础上，增加自定义规则判断：有匹配规则则应用自定义字段，无规则则保持默认自动响应：

import org.jpos.core.Configurable;
import org.jpos.core.Configuration;
import org.jpos.core.ConfigurationException;
import org.jpos.iso.ISOMsg;
import org.jpos.iso.ISORequestListener;
import org.jpos.iso.ISOSource;
import java.nio.file.Files;
import java.nio.file.Paths;

public class AutoResponder implements ISORequestListener, Configurable {
    private Configuration cfg;

    @Override
    public void setConfiguration(Configuration cfg) throws ConfigurationException {
        this.cfg = cfg;
        // 从配置指定路径加载自定义规则JSON
        try {
            String rulePath = cfg.get("rule-path");
            String jsonContent = new String(Files.readAllBytes(Paths.get(rulePath)));
            CustomResponseRepository.getInstance().loadConfig(jsonContent);
        } catch (Exception e) {
            throw new ConfigurationException("Failed to load custom response rules", e);
        }
    }

    @Override
    public boolean process(ISOSource source, ISOMsg m) {
        try {
            ISOMsg r = (ISOMsg) m.clone();
            r.setResponseMTI();

            // 查询当前交易的自定义响应规则
            TransactionRule.IssuerConfig customRule = CustomResponseRepository.getInstance().findIssuerResponse(m);
            if (customRule != null && customRule.getOut() != null) {
                // 应用所有自定义响应字段
                for (Map.Entry<String, String> entry : customRule.getOut().entrySet()) {
                    int fieldId = Integer.parseInt(entry.getKey());
                    r.set(fieldId, entry.getValue());
                }
            } else {
                // 无自定义规则，使用默认自动响应
                r.set(39, cfg.get("rc", "00"));
            }

            source.send(r);
        } catch (Exception e) {
            throw new RuntimeException("Could not process message", e);
        }
        return true;
    }
}

3. 调整Q2配置，添加规则路径参数 #

在mux的请求监听器配置中，指定自定义规则的JSON文件路径：

<mux class="org.jpos.q2.iso.QMUX" logger="Q2" name="iss-mux" realm="acq-realm">
<in>iss-channel-receive</in>
<out>iss-channel-send</out>
<ready>iss-channel.ready</ready>
<request-listener class="AutoResponder">
    <property name="rc" value="00"/>
    <!-- 指定自定义规则JSON文件的路径 -->
    <property name="rule-path" value="src/main/resources/custom_response_rules.json"/>
</request-listener>
</mux>

4. 可选：动态更新规则 #

如果需要在Q2运行时动态更新规则，可以新增一个JMX接口或HTTP接口，调用CustomResponseRepository.getInstance().loadConfig()方法重新加载JSON配置，无需重启Q2。

内容的提问来源于stack exchange，提问作者tytyty