tomcat之Container初始化与加载

不念不忘少年蓝@ 2023-06-08 14:00 142阅读 0赞

1. Container结构

![screenshot][]

Engine: servlet引擎

Host: 虚拟主机

Context: ServletContext,对应一个web项目或war包，包含多个Wrapper

Wrapper: 对Servlet的封装

2.  初始化

从Catalina类开始，主要涉及createStartDigester()方法，如下图所示

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTA2Mjc4NDA_size_16_color_FFFFFF_t_70][]

addObjectCreate方法调用路径 (加入队列)

public void addObjectCreate(String pattern, String className, String attributeName) {
    
            addRule(pattern, new ObjectCreateRule(className, attributeName));
    
        }

addRule方法

public void addRule(String pattern, Rule rule) {
    
            rule.setDigester(this);
            getRules().add(pattern, rule);
    
        }

add()方法

@Override
        public void add(String pattern, Rule rule) {
            // to help users who accidently add '/' to the end of their patterns
            int patternLength = pattern.length();
            if (patternLength>1 && pattern.endsWith("/")) {
                pattern = pattern.substring(0, patternLength-1);
            }
    
    
            List<Rule> list = cache.get(pattern);
            if (list == null) {
                list = new ArrayList<>();
                cache.put(pattern, list);
            }
            list.add(rule);
            rules.add(rule);
            if (this.digester != null) {
                rule.setDigester(this.digester);
            }
            if (this.namespaceURI != null) {
                rule.setNamespaceURI(this.namespaceURI);
            }
    
        }

rules和cache定义

>     protected ArrayList<Rule> rules = new ArrayList<>();
> 
>     protected HashMap<String,List<Rule>> cache = new HashMap<>();

StandardService类包含多个Connector和一个Engine

/**
         * The <code>Server</code> that owns this Service, if any.
         */
        private Server server = null;
       
        protected Connector connectors[] = new Connector[0];
        private final Object connectorsLock = new Object();
    
        /**
         *
         */
        protected final ArrayList<Executor> executors = new ArrayList<>();
    
        private Engine engine = null;

[screenshot]: /images/20230531/1fd5665580e449168a92129f6520c822.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTA2Mjc4NDA_size_16_color_FFFFFF_t_70]: /images/20230531/e6e9dc901617463fb4e09a107eb139f7.png