Using Java Reflection to Execute API Test Cases in an HttpClient Framework

The author describes building a simple HttpClient-based API testing framework in Java, repeatedly refactoring it until a long‑standing issue was resolved, with a key technique being the use of Java reflection to invoke methods based on parameter names.

Below is the optimized method for executing all test cases of a single API interface:

// 发帖话题分类接口 001
public void case_shequ_topic_cattlist() {
    String apiName = "shequ_topic_cattlist";
    mark = getMark();
    executeCase(apiName, mark);
}

Below is the optimized method for executing a single test case of an API interface:

// 创建帖子接口 002
public void case_shequ_post_create() {
    String apiName = "shequ_post_create";
    mark = getMark();
    executeCase(apiName, mark);
}

The executeCase() method reads test cases from a MySQL database, iterates over them, extracts expected and actual verification values, compares results, writes outcomes back to the database, and finally aggregates the run statistics:

public void executeCase(String apiName, int mark) {
    List<Map<String, String>> data = LocalMySql.getInstance().getCaseFromMySql(apiName);// 数据库读取用例
    for (int i = 0; i < data.size(); i++) {// 遍历执行用例
        Map<String, String> use = data.get(i);// 获取单个用例
        String case_id = use.get("case_id");
        String expect_value1 = use.get("verify_value1");// 获取验证点期望值
        String expect_value2 = use.get("verify_value2");// 获取验证点期望值
        String expect_value3 = use.get("verify_value3");// 获取验证点期望值
        String actual_key1 = use.get("verify_key1");// 获取检查点key
        String actual_key2 = use.get("verify_key2");// 获取检查点key
        String actual_key3 = use.get("verify_key3");// 获取检查点key
        String params = use.toString();// 记录传入参数
        JSONObject response = executeMethodByName(apiName, use);
        String actual_value1 = getDataValue(response, actual_key1);// 获取验证点实际值
        String actual_value2 = getDataValue(response, actual_key2);// 获取验证点实际值
        String actual_value3 = getDataContains(response, actual_key3, expect_value3);// 获取验证点实际值，此为包含验证
        String[] data2 = { expect_value1, actual_value1, expect_value2, actual_value2, expect_value3,
                actual_value3 };
        int result = getResult(data2) ? 1 : 2;// 获取测试结果，1为通过，2为失败
        LocalMySql.getInstance().saveApiTestResult(case_id, mark, result, apiName, expect_value1, actual_value1,
                expect_value2, actual_value2, expect_value3, actual_value3, params);// 写入数据库
    }
    LocalMySql.getInstance().addApiTestResult(apiName, mark, test_mark);// 统计本次运行所有用例结果
}

The executeMethodByName() method demonstrates how reflection is used to load a class, obtain a method by its name, invoke it with a map of parameters, and return the resulting JSON object:

public JSONObject executeMethodByName(String apiName, Map<String, String> use) {
    JSONObject jsonObject = null;
    Object obj = null;
    Method method = null;
    try {
        // 里面写自己的类名及路径
        Class<?> c = Class.forName("juziyule.Special_juzi");
        obj = c.newInstance();
        // 第一个参数写的是方法名,第二个\第三个\...写的是方法参数列表中参数的类型
        method = c.getMethod(apiName, Map.class);
        // invoke是执行该方法,并携带参数值
    } catch (Exception e) {
        output("反射执行出错！", e);
    }
    try {
        jsonObject = (JSONObject) method.invoke(obj, new Object[] { use });
    } catch (Exception e) {
        output("反射运行方法异常！", e);
    }
    return jsonObject;
}