tomcat之Container初始化與加載

1. Container結構

Engine: servlet引擎

Host: 虛擬主機

Context: ServletContext,對應一個web項目或war包，包含多個Wrapper

Wrapper: 對Servlet的封裝 

 

2.  初始化

從Catalina類開始，主要涉及createStartDigester()方法，如下圖所示

 addObjectCreate方法調用路徑 (加入隊列)

  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定義

protected ArrayList<Rule> rules = new ArrayList<>();

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

 

StandardService類包含多個Connector和一個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;