/**
 * WEB测试用例
 */
public class WebTestCase implements Callable<List<Integer>> {
    /**
     * 接口URL
     */
    private String url;
    /**
     * 每个用户请求数量
     */
    private int reqCount;
    public WebTestCase(String url,int reqCount) {
        this.url = url;
        this.reqCount = reqCount;
    }
    public List<Integer> call() throws Exception {
        List<Integer> spendTimes = new ArrayList<Integer>();
        for(int i = 0;i< reqCount;i++){
            Long startMills = System.currentTimeMillis();
            String result =  httpRequest(url,"GET",null);
            Long endMills = System.currentTimeMillis();
            Long spendTime = endMills - startMills;
            spendTimes.add(spendTime.intValue());
            System.out.println("线程"+Thread.currentThread().getName()+"第"+(i+1)+"次:"+spendTime.intValue()+"ms");
        }
        return spendTimes;
    }
    public static String httpRequest(String requestUrl, String requestMethod, String outputStr) {
        StringBuffer buffer = new StringBuffer();
        try {
            URL url = new URL(requestUrl);
            HttpURLConnection httpUrlConn = (HttpURLConnection)url.openConnection();
            httpUrlConn.setDoOutput(true);
            httpUrlConn.setDoInput(true);
            httpUrlConn.setUseCaches(false);
            httpUrlConn.setConnectTimeout(500);
            httpUrlConn.setRequestMethod(requestMethod);
            if ("GET".equalsIgnoreCase(requestMethod))
                httpUrlConn.connect();
            if (outputStr != null) {
                OutputStream outputStream = httpUrlConn.getOutputStream();
                outputStream.write(outputStr.getBytes("UTF-8"));
                outputStream.close();
            }
            InputStream inputStream = httpUrlConn.getInputStream();
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String str = null;
            while ((str = bufferedReader.readLine()) != null){
                buffer.append(str);
            }
            bufferedReader.close();
            inputStreamReader.close();
            inputStream.close();
            inputStream = null;
            httpUrlConn.disconnect();
        } catch (ConnectException ce) {
            ce.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return buffer.toString();
    }
}
/**
 * 测试结果
 */
public class WebTestResult {
    /**
     * 平均响应时间
     */
    private Double avgRespMills;
    /**
     * 95%响应时间
     */
    private Double nintyFivePercentileRespMills;
    public WebTestResult(Double avgRespMills, Double nintyFivePercentileRespMills) {
        this.avgRespMills = avgRespMills;
        this.nintyFivePercentileRespMills = nintyFivePercentileRespMills;
    }
    @Override
    public String toString() {
        return "WebTestResult{" +
                "avgRespMills=" + avgRespMills +
                ", nintyFivePercentileRespMills=" + nintyFivePercentileRespMills +
                '}';
    }
}
/**
 * 程序入口
 */
public class Starter {
    /**
     * 程序入口
     * @param args
     */
    public static void main(String[] args) {
        WebTestResult result = test("https://www.baidu.com",10,100);
        System.out.println(result);
    }
    /**
     * 测试方法
     * @param url 测试地址
     * @param userCount 用户数量
     * @param reqCount 每个用户访问多少次
     */
    public static WebTestResult test(String url,int userCount,int reqCount){
        ExecutorService executorService = Executors.newFixedThreadPool(userCount);
        CompletionService<List<Integer>> cs = new ExecutorCompletionService<List<Integer>>(executorService);
        for (int i = 0; i < userCount; i++){
            cs.submit(new WebTestCase(url,reqCount));
        }
        double[] timesList = new double[userCount * reqCount];
        int index = 0;
        for (int i = 0; i < userCount; i++) {
            try {
                List<Integer> list = cs.take().get();
                for(Integer time : list){
                    timesList[index] = time.doubleValue();
                    index = index + 1;
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            }
        }
        executorService.shutdown();
        Percentile percentile = new Percentile(0.95);
        double nintyFivepercentile = percentile.evaluate(timesList);
        Mean mean = new Mean(); // 算术平均值
        double average = mean.evaluate(timesList);
        WebTestResult result = new WebTestResult(average,nintyFivepercentile);
        return result;
    }
}