首先，检查代码是否正确调用了B2C API连接器。如果没有，请按照以下示例代码使用B2C API连接器：

// 导入所需的包
import com.sap.conn.jco.JCoDestination;
import com.sap.conn.jco.JCoDestinationManager;
import com.sap.conn.jco.JCoFunction;
import com.sap.conn.jco.JCoParameterList;
import com.sap.conn.jco.JCoRepository;
import com.sap.conn.jco.ext.DestinationDataProvider;

// 定义与B2C系统的连接配置
public class MyDestinationDataProvider implements DestinationDataProvider {

    private static MyDestinationDataProvider provider = null;

    private MyDestinationDataProvider() {
    }

    public synchronized static MyDestinationDataProvider getInstance() {
        if (provider == null) {
            provider = new MyDestinationDataProvider();
        }
        return provider;
    }

    @Override
    public Properties getDestinationProperties(String destinationName) {
        if (destinationName.equalsIgnoreCase("MyB2CSystem")) {
            Properties connectProperties = new Properties();
            connectProperties.setProperty(DestinationDataProvider.JCO_ASHOST, "B2C系统主机名");
            connectProperties.setProperty(DestinationDataProvider.JCO_SYSNR, "B2C系统实例号");
            connectProperties.setProperty(DestinationDataProvider.JCO_CLIENT, "B2C系统客户端号");
            connectProperties.setProperty(DestinationDataProvider.JCO_USER, "B2C系统用户名");
            connectProperties.setProperty(DestinationDataProvider.JCO_PASSWD, "B2C系统密码");
            connectProperties.setProperty(DestinationDataProvider.JCO_LANG, "en");
            return connectProperties;
        }
        return null;
    }

    @Override
    public void setDestinationDataEventListener(DestinationDataEventListener arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean supportsEvents() {
        // TODO Auto-generated method stub
        return false;
    }

}

// 获取连接器实例
JCoDestination destination = JCoDestinationManager.getDestination("MyB2CSystem");

// 获取连接后获取函数执行器和参数列表
JCoRepository repository = destination.getRepository();
JCoFunction function = repository.getFunction("Function_Name");
JCoParameterList input = function.getImportParameterList();

// 设置输入参数
input.setValue("Parameter_Name", "Parameter_Value");

// 执行函数
function.execute(destination);

// 获取输出参数
JCoParameterList output = function.getExportParameterList();
String returnValue = output.getString("Return_Value");

请替换示例代码中的“B2C系统主机名”、“B2C系统实例号”、“B2C系统客户端号”、“B2C系统用户名”和“B2C系统密码