项目所遇知识点

1.hashset中的add()方法添加重复元素

2.比较两个乱序的字符串,排序后是否相同,可以考虑使用ASCII

3.数组.tostring输出是哈希值,Arrays.toString(数组)输出的是字符串

4.list相互转换

        List<FileDigestSignResultFinally> fileDigestSignResultFinallies = JSON.parseArray(JSON.toJSONString(successList), FileDigestSignResultFinally.class);

 5.初始化been

      构造方法 > @PostContruct > afterPropertiesSet() > init-method

@Component
public class BeanInit implements InitializingBean {
    private static Logger log = LoggerFactory.getLogger(BeanInit.class);
    @Autowired
    private NettyServer nettyServer;
    public BeanInit() {
        init2();
    }
    @Override
    public void afterPropertiesSet() throws Exception {
        log.info("netty----------------------------------");
        init();
    }
    private void init() {
        /** 另起一个线程器启动netty，主线程继续启动项目 **/
        new Thread(){
            @Override
            public void run() {
                nettyServer.start();
            }
        }.start();
        log.info("netty对外服务端已启动...");
    }
    @PostConstruct
    public void init1() {
        log.info("通过@PostConstruct注解，实现项目启动时加载缓存...");
    }
    public void init2() {
        log.info("通过放入bean构造方法，实现项目启动时加载缓存...");
    }
    @Bean(initMethod = "init")
    public void init3() {
        log.info("通过配置@bean的init-method属性，实现项目启动时加载缓存...");
    }
}

 6.属性复制

?

1 2 3

<div id="mCSB_3" class="mCustomScrollBox mCS-minimal-dark mCSB_vertical_horizontal mCSB_outside" style="max-height: none;" tabindex="0"><div id="mCSB_3_container" class="mCSB_container mCS_y_hidden mCS_no_scrollbar_y mCS_x_hidden mCS_no_scrollbar_x" style="position: relative; top: 0px; left: 0px; width: 100%;" dir="ltr"><code-pre class="code-pre" id="pre-8fW87D"><code-line class="line-numbers-rows"></code-line>// 将custHikariDataSourceProperties对象复制到dataSource 并且忽略"driverClassName","exceptionOverrideClassName"属性 <code-line class="line-numbers-rows"></code-line> BeanUtils.copyProperties(custHikariDataSourceProperties, dataSource, "driverClassName","exceptionOverrideClassName"); </code-pre></div></div><div id="mCSB_3_scrollbar_vertical" class="mCSB_scrollTools mCSB_3_scrollbar mCS-minimal-dark mCSB_scrollTools_vertical" style="display: none;"><div class="mCSB_draggerContainer"><div id="mCSB_3_dragger_vertical" class="mCSB_dragger" style="position: absolute; min-height: 0px; height: 0px; top: 0px;"><div class="mCSB_dragger_bar" style="line-height: 0px;"></div></div><div class="mCSB_draggerRail"></div></div></div><div id="mCSB_3_scrollbar_horizontal" class="mCSB_scrollTools mCSB_3_scrollbar mCS-minimal-dark mCSB_scrollTools_horizontal" style="display: none;"><div class="mCSB_draggerContainer"><div id="mCSB_3_dragger_horizontal" class="mCSB_dragger" style="position: absolute; min-width: 0px; width: 0px; left: 0px;"><div class="mCSB_dragger_bar"></div></div><div class="mCSB_draggerRail"></div></div></div>

 7.　sql优化

?

1 2 3 4 5 6 7 8 9

<div id="mCSB_4" class="mCustomScrollBox mCS-minimal-dark mCSB_vertical_horizontal mCSB_outside" style="max-height: none;" tabindex="0"><div id="mCSB_4_container" class="mCSB_container mCS_y_hidden mCS_no_scrollbar_y mCS_x_hidden mCS_no_scrollbar_x" style="position: relative; top: 0px; left: 0px; width: 100%;" dir="ltr"><code-pre class="code-pre" id="pre-JmHdzW"><code-line class="line-numbers-rows"></code-line>选择合适的列进行索引 <code-line class="line-numbers-rows"></code-line>使用复合索引(注意索引的顺序也能进一步影响快慢) <code-line class="line-numbers-rows"></code-line>选择合适的索引类型:根据查询的特性选择合适的索引类型。常见的索引类型包括B-tree索引、哈希索引、全文索引等。 <code-line class="line-numbers-rows"></code-line>避免过度索引 <code-line class="line-numbers-rows"></code-line>使用覆盖索引( COUNT(*) 和 COUNT(单字段)的区别 ) <code-line class="line-numbers-rows"></code-line>注意索引的顺序 <code-line class="line-numbers-rows"></code-line>避免在索引列上使用函数 <code-line class="line-numbers-rows"></code-line>慢sql查询(如索引在Username上 ...WHERE LENGTH(Username) > 5; 没有...WHERE Username > '_____'; -- 使用5个下划线表示长度为5的字符串 快) </code-pre></div></div><div id="mCSB_4_scrollbar_vertical" class="mCSB_scrollTools mCSB_4_scrollbar mCS-minimal-dark mCSB_scrollTools_vertical" style="display: none;"><div class="mCSB_draggerContainer"><div id="mCSB_4_dragger_vertical" class="mCSB_dragger" style="position: absolute; min-height: 0px; height: 0px; top: 0px;"><div class="mCSB_dragger_bar" style="line-height: 0px;"></div></div><div class="mCSB_draggerRail"></div></div></div><div id="mCSB_4_scrollbar_horizontal" class="mCSB_scrollTools mCSB_4_scrollbar mCS-minimal-dark mCSB_scrollTools_horizontal" style="display: none;"><div class="mCSB_draggerContainer"><div id="mCSB_4_dragger_horizontal" class="mCSB_dragger" style="position: absolute; min-width: 0px; width: 0px; left: 0px;"><div class="mCSB_dragger_bar"></div></div><div class="mCSB_draggerRail"></div></div></div>

 8. ConditionalOnProperty 配置匹配才会加载

?

1 2 3 4 5 6

<div id="mCSB_5" class="mCustomScrollBox mCS-minimal-dark mCSB_vertical_horizontal mCSB_outside" style="max-height: none;" tabindex="0"><div id="mCSB_5_container" class="mCSB_container mCS_y_hidden mCS_no_scrollbar_y mCS_x_hidden mCS_no_scrollbar_x" style="position: relative; top: 0px; left: 0px; width: 100%;" dir="ltr"><code-pre class="code-pre" id="pre-GeTiam"><code-line class="line-numbers-rows"></code-line>@ConditionalOnProperty(prefix = "sync.counters", name = "account", havingValue = "ksp") <code-line class="line-numbers-rows"></code-line>@Configuration <code-line class="line-numbers-rows"></code-line>@ComponentScan(basePackages = {"ks.fintech.unicenter.sync.account.ksp"}) <code-line class="line-numbers-rows"></code-line>public class KspAccountConfigure { <code-line class="line-numbers-rows"></code-line>} </code-pre></div></div><div id="mCSB_5_scrollbar_vertical" class="mCSB_scrollTools mCSB_5_scrollbar mCS-minimal-dark mCSB_scrollTools_vertical" style="display: none;"><div class="mCSB_draggerContainer"><div id="mCSB_5_dragger_vertical" class="mCSB_dragger" style="position: absolute; min-height: 0px; height: 0px; top: 0px;"><div class="mCSB_dragger_bar" style="line-height: 0px;"></div></div><div class="mCSB_draggerRail"></div></div></div><div id="mCSB_5_scrollbar_horizontal" class="mCSB_scrollTools mCSB_5_scrollbar mCS-minimal-dark mCSB_scrollTools_horizontal" style="display: none;"><div class="mCSB_draggerContainer"><div id="mCSB_5_dragger_horizontal" class="mCSB_dragger" style="position: absolute; min-width: 0px; width: 0px; left: 0px;"><div class="mCSB_dragger_bar"></div></div><div class="mCSB_draggerRail"></div></div></div>

　　

 

__EOF__

本文作者：皮军旗
本文链接：https://www.cnblogs.com/pijunqi/p/15432592.html
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