Java高并发及测试代码-白红宇

Java高并发及测试代码

阅读量：6595 次

发布时间：2019-06-24

本文共 8224 字，大约阅读时间需要 27 分钟。

公司的妹子不会做并发测试。做完一名程序猿看着有点干捉急。并发测试是多个人同时访问一个服务，这不就是多线程吗！于是灵光一现使用多线程来写并发测试代码。想想心理都有点小激动咧。效果比工具还好，废话不多说贴代码

添加Maven依赖


    
     com.squareup.okhttp3
    
    
     okhttp
    
    
     3.8.1

</dependency>


    
     com.squareup.okio
    
    
     okio
    
    
     1.11.0

</dependency>


    
     com.google.code.gson
    
    
     gson
    
    
     2.8.0

</dependency>

先封装OKHTTP（使用CallBack思想做的封装），这个很早之前就封装了，公司移动端也是使用OKHTTP做的服务请求调用。经常遇到图片上传不了的问题，报的错是Socket连接超时的问题。解决这个问题so easy，把连接时间（KEEP_ALIVE）时间设置长一点就行了嘛！

OkHttp底层是用socket做的通信，现在很多应该的底层通信都用的Socket，例子不多说，全靠经验。

public abstract class HttpCommon {

/** * 设置连接超时时间为30000秒 */private final static int CONNECT_TIMT_OUT = 30000;/** * 设置写超时时间为30000秒 */private final static int WRITE_TIME_OUT = 30000;static {    final OkHttpClient.Builder httpBuilder = new OkHttpClient.Builder();    okHttpClient = httpBuilder.connectTimeout(CONNECT_TIMT_OUT, TimeUnit.SECONDS)            .writeTimeout(WRITE_TIME_OUT, TimeUnit.SECONDS).build();}public abstract void callBack(String responseString);/** * get请求 * * @param url url地址 * @param map 请求参数 * @return 返回结果。如果为“”表示失败 */public void get(String url, Map
    
      map) {    url = wrapUrl(url, map);    // 创建请求参数    Request request = new Request.Builder().url(url).build();    //创建请求对象    Call call = okHttpClient.newCall(request);    try {        Response response = call.execute();        if (response.isSuccessful()) {            callBack(response.body().string());        }    } catch (IOException e) {        e.printStackTrace();    }}/** * post请求 * * @param url post请求的url * @param t   post请求的表单实体 * @return 返回结果。如果为“”表示失败 */public 
     
       void post(String url, Map
      
        map, T t) {    url = wrapUrl(url, map);    String json = new Gson().toJson(t);    RequestBody body = RequestBody.create(JSON, json);    Request request = new Request.Builder().url(url).post(body).build();    Response response = null;    try {        response = okHttpClient.newCall(request).execute();        if (response.isSuccessful()) {            callBack(response.body().string());        }    } catch (IOException e) {        e.printStackTrace();    }}/** * post请求 * * @param url post请求的url * @param t   post请求的表单实体 * @return 返回结果。如果为“”表示失败 */public 
       
         void post(String url, T t) {    String json = new Gson().toJson(t);    RequestBody body = RequestBody.create(JSON, json);    Request request = new Request.Builder().url(url).post(body).build();    Response response = null;    try {        response = okHttpClient.newCall(request).execute();        if (response.isSuccessful()) {            callBack(response.body().string());        }    } catch (IOException e) {        e.printStackTrace();    }}/** * 上传文件请求 * * @param url      请求url * @param map      请求参数 * @param filePath 文件路径 * @return 返回结果。结果为""表示失败 */private void uploadFile(String url, Map
        
          map, String filePath) {    url = wrapUrl(url, map);    File file = new File(filePath);    RequestBody fileBody = RequestBody.create(OCTET, file);    RequestBody requestBody = new MultipartBody.Builder().setType(MultipartBody.FORM)            .addFormDataPart("image", file.getName(), fileBody).build();    Request request = new Request.Builder().url(url).post(requestBody).build();    execute(request);}/** * 上传多个文件请求 * * @param url       请求url * @param map       请求参数 * @param filePaths 文件路径 * @return 返回结果。结果为""表示失败 */private void uploadFiles(String url, Map
         
           map, List
          
            filePaths) { url = wrapUrl(url, map); MultipartBody.Builder builder = new MultipartBody.Builder(); builder.setType(MultipartBody.FORM); for (String str : filePaths) { File file = new File(str); RequestBody fileBody = RequestBody.create(OCTET, file); builder.addFormDataPart("image", file.getName(), fileBody); } RequestBody requestBody = builder.build(); Request request = new Request.Builder().url(url).post(requestBody).build(); execute(request);}/** * 执行文件上传操作 * * @param request */private void execute(Request request) { try { Response response = okHttpClient.newCall(request).execute(); if (response.isSuccessful()) { callBack(response.body().string()); } } catch (IOException e) { e.printStackTrace(); }}/** * 拼接get请求url * * @param url 请求url * @param map 参数 * @return 返回拼接完的url地址 */private String wrapUrl(String url, Map
           
             map) { if (null == map) { return url; } url += "?"; for (Map.Entry entry : map.entrySet()) { url += entry.getKey() + "=" + entry.getValue() + "&"; } if (url.endsWith("&")) { url = url.substring(0, url.length() - 1); } return url;}/** * 请求客户端 */private static OkHttpClient okHttpClient;/** * Json媒体类型 */private static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");/** * 二进制流的媒体类型 */private static final MediaType OCTET = MediaType.parse("application/octet-stream");

}

public class RunThread {

private final String URL;private HttpCommon httpCommon;private int num;private static ThreadPoolExecutor executor = new ThreadPoolExecutor(10, 100, 1000000L, TimeUnit.SECONDS, new LinkedBlockingDeque<>());private CountDownLatch countDownLatch;/** * @param url 服务URL地址， * @param num 并发访问次数，一般配置50+ */public RunThread(String url, int num) {    this.URL = url;    this.num = num;    this.countDownLatch = new CountDownLatch(num);    httpCommon = new HttpCommon() {        @Override        public void callBack(String responseString) {            System.out.println(responseString);        }    };}public void testGet(Map
    
      map) {    long startTime = System.currentTimeMillis();    for (int i = 0; i < num; i++) {        executor.execute(new Runnable() {            @Override            public void run() {                httpCommon.get(URL, map);                countDownLatch.countDown();            }        });    }    try {        countDownLatch.await();        long executeTime = System.currentTimeMillis() - startTime;        System.out.println("一共消耗：" + executeTime +"毫秒");    } catch (InterruptedException e) {        e.printStackTrace();    }}public 
     
       void testPost(Map
      
        map, T t) {    long startTime = System.currentTimeMillis();    for (int i = 0; i < num; i++) {        executor.execute(new Runnable() {            @Override            public void run() {                httpCommon.post(URL, map, t);                countDownLatch.countDown();            }        });    }    try {        countDownLatch.wait();        long executeTime = System.currentTimeMillis() - startTime;        System.out.println("一共消耗：" + executeTime +"毫秒");    } catch (InterruptedException e) {        e.printStackTrace();    }}

}

public static void main(String[] args) {    String Url = "http://localhost:8085/test/add";    RunThread testMain = new RunThread(Url, 1000);    // 测试Get请求    testMain.testGet(new HashMap<>());

// // 测试POST请求、PUT请求、DELETE请求

// testMain.testPost(new HashMap<>(), null);

上面是并发测试代码，那么如何写高并发测试代码呢！想到两点：一个锁、一个事务。先用Oracle做实验。

insert into testa  (aaaa, bbbb)values  (#{aaa}, #{aaa})

</insert>

select max(aaaa) from testa

</select>

Service层代码，设置事务的隔离级别为不可重复读

Isolation.REPEATABLE_READ，结果报错“Could not open JDBC Connection for transaction; nested exception is java.sql.SQLException: 仅 READ_COMMITTED 和 SERIALIZABLE 是有效的事务处理级”。卧槽！还能不能一起愉快地玩耍了，Oracle居然只支持可重复读和可系列化两种事务级别，真是让人大跌眼镜。

贴一下高并发代码吧，经过实验，通过1000个并发请求，使用Durid + Lock成功1百个不到（在这里还是得喷一下阿里的技术），使用dbcp2 + Lock成功2百多个，使用dbcp2 + synchronized 竟然成功了940个。

@Autowired

private TestMapper testMapper;

//private Lock lock = new ReentrantLock();

@Transactional(isolation = Isolation.SERIALIZABLE)

public synchronized Integer test(Integer a, Integer b) {

int c = testMapper.select();    c += 1;    testMapper.insert(c);    return c;

}

代码有问题，找找错误原因吧。Spring AOP执行事务，会在Service方法执行之前就开始事务，再执行Synchronized同步方法。这样会导致查询数据并没有做同步，修改成如下代码，能完美解决问题。测试得出如下代码的执行效率最高，1000个并发耗时9018毫秒

@Autowired

private TestMapper testMapper;

//private Lock lock = new ReentrantLock();

public synchronized Integer test(Integer a, Integer b) {

int c = testMapper.select();c += 1;update(c);return c;

}

@Transactional(isolation = Isolation.SERIALIZABLE)

public void update(int c) {

testMapper.insert(c);

}

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