Gatling Java跨Simulation文件调用Scenario的权限问题求解

问题背景 #

原本使用Gatling/Scala，现在转用Gatling/Java，尝试在/assignments/performance/simulations/BaseSimulation.java中调用/assignments/performance/scenarios/LoginScenario/TeacherLoginFlow.java里的LoginFlow场景，但编译报错：

'LoginFlow' is not public in 'com.hmhco.assignments.performance.scenarios.LoginScenario.TeacherLoginFlow'. Cannot be accessed from outside package

错误原因 #

TeacherLoginFlow里的LoginFlow变量没有添加public修饰符，默认是包访问权限，只能被同一个包内的类访问，而BaseSimulation在不同的包下，所以无法直接访问。

解决方案 #

步骤1：修改LoginFlow的访问权限 #

在TeacherLoginFlow类中，给LoginFlow加上public static修饰符（用static可以不用创建类实例直接调用，更适合场景复用）：

修改后的TeacherLoginFlow.java核心代码：

package com.hmhco.assignments.performance.scenarios.LoginScenario;

import io.gatling.javaapi.core.ScenarioBuilder;
import io.gatling.javaapi.http.HttpProtocolBuilder;
import io.gatling.javaapi.core.FeederBuilder;
import static io.gatling.javaapi.core.CoreDsl.*;
import static io.gatling.javaapi.http.HttpDsl.http;
import java.util.HashMap;
import java.util.Map;

public class TeacherLoginFlow {
    // 建议把常量定义为public static final，方便全局复用
    public static final String BASE_URL = "你的基础URL";
    public static final int AUTH_FLOW_REPEAT = 1;

    public static Map<String, String> myMap = new HashMap<>();

    public static HttpProtocolBuilder httpProtocol = http
            .baseUrl(BASE_URL)
            .shareConnections();

    public static FeederBuilder teachers = csv("data/teachers.csv").circular();

    // 添加public static修饰符，允许跨包访问
    public static ScenarioBuilder loginFlow = scenario("auth-flow").repeat(AUTH_FLOW_REPEAT).on(
            feed(teachers)
                    .exec(session -> {
                        // 原有业务逻辑代码
                        return session;
                    })
                    // 其他exec步骤
    );
}

注：Java规范中变量名建议小驼峰格式（loginFlow而非LoginFlow），可根据习惯调整，但权限修饰符必须添加。

步骤2：修改BaseSimulation的调用逻辑 #

不需要重复定义feeder，直接复用TeacherLoginFlow里的场景即可，简化代码：

修改后的BaseSimulation.java核心代码：

package com.hmhco.assignments.performance.simulations;

import com.hmhco.assignments.performance.scenarios.LoginScenario.TeacherLoginFlow;
import io.gatling.javaapi.core.Simulation;
import io.gatling.javaapi.core.ScenarioBuilder;
import static io.gatling.javaapi.core.CoreDsl.*;

public class BaseSimulation extends Simulation {
    // 定义模拟参数
    private static final int NUMBER_OF_USERS = 100;
    private static final int RAMP_UP = 60; // 单位：秒
    private static final int MAX_DURATION = 300; // 单位：秒

    // 直接复用TeacherLoginFlow中的场景
    private ScenarioBuilder loginTeacherUsers = TeacherLoginFlow.loginFlow;

    {
        setUp(
                loginTeacherUsers.injectOpen(rampUsers(NUMBER_OF_USERS).during(RAMP_UP))
        ).maxDuration(MAX_DURATION)
                // 复用TeacherLoginFlow中定义的http协议配置
                .protocols(TeacherLoginFlow.httpProtocol);
    }
}

额外优化建议 #

如果场景需要动态参数，可以把loginFlow改成静态方法，接收参数后返回ScenarioBuilder，示例：

// 在TeacherLoginFlow中添加静态方法
public static ScenarioBuilder getLoginFlow(int repeatCount) {
    return scenario("auth-flow").repeat(repeatCount).on(
            feed(teachers)
                    .exec(session -> {
                        // 业务逻辑代码
                        return session;
                    })
    );
}

在BaseSimulation中调用：

private ScenarioBuilder loginTeacherUsers = TeacherLoginFlow.getLoginFlow(2);

内容的提问来源于stack exchange，提问作者Alexb1999