Javaマルチスレッド(4)のスレッド閉鎖

スレッド閉鎖:オブジェクトを1つのスレッドにカプセル化します.

スレッドを閉じる方法:

ad-hocスレッド閉鎖:プログラム制御、最悪、ゆらゆら;

スタック閉鎖:ローカル変数、同時問題なし(グローバル変数、スレッドセキュリティ問題を引き起こしやすい)

TreadLocalスレッド閉鎖:特に良い閉鎖方法.

私たちが普段書いているコードは、スレッドセキュリティの問題がなく、スタックが閉鎖されているためです.
TreadLocalの使用:
1.requestHolderの作成

package com.liuhy.test.testapplication.trhreadlocal;

import sun.rmi.runtime.Log;

/**
 * @Auther: liuhy
 * @Date: 2018/11/26 17:33
 */
public class RequestHolder {

    private final static ThreadLocal requestHolder =  new ThreadLocal<>();

    public static void add(Long id){
        requestHolder.set(id);
    }

    public static Long getId(){
        return requestHolder.get();
    }

    public static void remove(){
        requestHolder.remove();
    }

}

2、filterの作成と追加

package com.liuhy.test.testapplication.filter;


import com.liuhy.test.testapplication.trhreadlocal.RequestHolder;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
 * @Auther: liuhy
 * @Date: 2018/11/26 17:36
 */
@Slf4j
public class HttpFileter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //  ServletRequest   HttpServletRequest
        HttpServletRequest request=(HttpServletRequest)servletRequest;

        log.info("do filter,{},{}",Thread.currentThread().getId(),request.getServletPath());
        // uri ， controller id TreadLocal 
        RequestHolder.add(Thread.currentThread().getId());
        filterChain.doFilter(request,servletResponse);
    }

    @Override
    public void destroy() {

    }
}

3、ブロッキングの追加

package com.liuhy.test.testapplication.filter;

import com.liuhy.test.testapplication.trhreadlocal.RequestHolder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @Auther: liuhy
 * @Date: 2018/11/26 17:52
 */
@Slf4j
public class HttpInterceptor extends HandlerInterceptorAdapter {

    /**
     *  
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        log.info("preHandler");

        return super.preHandle(request, response, handler);
    }

    /**
     *  
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        //   
        RequestHolder.remove();
        log.info("afterHandler");
        super.afterCompletion(request, response, handler, ex);
    }
}

 
4、filter及びIntercepterの登録

package com.liuhy.test.testapplication;

import com.liuhy.test.testapplication.filter.HttpFileter;
import com.liuhy.test.testapplication.filter.HttpInterceptor;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * @Auther: liuhy
 * @Date: 2018/11/26 17:56
 */
@Configuration
public class Config implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new HttpInterceptor());
    }

    @Bean
    public FilterRegistrationBean httpFilter(){
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        registrationBean.setFilter(new HttpFileter());
        registrationBean.addUrlPatterns("/threadLocal/*");
        return registrationBean;
    }
}

5、インスタンスコントローラ使用

package com.liuhy.test.testapplication.trhreadlocal;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

/**
 * @Auther: liuhy
 * @Date: 2018/11/26 18:02
 */
@Controller
@RequestMapping("/threadLocal")
public class ThreadLocalController {

    @RequestMapping("/test")
    @ResponseBody
    public String getLocal(){
        Long id = RequestHolder.getId();

        return "this is ThreadLocal "+id;
    }
}