Servlet下

servlet容器启动过程

Web应用的初始化工作

创建Servlet实例

在Servlet的解析工作中，Servlet被包装成StandarWrapper添加在Context容器中。

servlet 体系结构

servlet interface:

package javax.servlet;

import java.io.IOException;

public interface Servlet {
    void init(ServletConfig var1) throws ServletException;

    ServletConfig getServletConfig();

    void service(ServletRequest var1, ServletResponse var2) throws ServletException, IOException;

    String getServletInfo();

    void destroy();
}

servletConfig interface:

package javax.servlet;

import java.util.Enumeration;

public interface ServletConfig {
    String getServletName();

    ServletContext getServletContext();

    String getInitParameter(String var1);

    Enumeration getInitParameterNames();
}

servletContext interface:

package javax.servlet;

import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Enumeration;
import java.util.Set;

public interface ServletContext {
    String getContextPath();

    ServletContext getContext(String var1);

    int getMajorVersion();

    int getMinorVersion();

    String getMimeType(String var1);

    Set getResourcePaths(String var1);

    URL getResource(String var1) throws MalformedURLException;

    InputStream getResourceAsStream(String var1);

    RequestDispatcher getRequestDispatcher(String var1);

    RequestDispatcher getNamedDispatcher(String var1);

    /** @deprecated */
    Servlet getServlet(String var1) throws ServletException;

    /** @deprecated */
    Enumeration getServlets();

    /** @deprecated */
    Enumeration getServletNames();

    void log(String var1);

    /** @deprecated */
    void log(Exception var1, String var2);

    void log(String var1, Throwable var2);

    String getRealPath(String var1);

    String getServerInfo();

    String getInitParameter(String var1);

    Enumeration getInitParameterNames();

    Object getAttribute(String var1);

    Enumeration getAttributeNames();

    void setAttribute(String var1, Object var2);

    void removeAttribute(String var1);

    String getServletContextName();
}

servletRequest interface:

package javax.servlet;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Enumeration;
import java.util.Locale;
import java.util.Map;

public interface ServletRequest {
    Object getAttribute(String var1);

    Enumeration getAttributeNames();

    String getCharacterEncoding();

    void setCharacterEncoding(String var1) throws UnsupportedEncodingException;

    int getContentLength();

    String getContentType();

    ServletInputStream getInputStream() throws IOException;

    String getParameter(String var1);

    Enumeration getParameterNames();

    String[] getParameterValues(String var1);

    Map getParameterMap();

    String getProtocol();

    String getScheme();

    String getServerName();

    int getServerPort();

    BufferedReader getReader() throws IOException;

    String getRemoteAddr();

    String getRemoteHost();

    void setAttribute(String var1, Object var2);

    void removeAttribute(String var1);

    Locale getLocale();

    Enumeration getLocales();

    boolean isSecure();

    RequestDispatcher getRequestDispatcher(String var1);

    /** @deprecated */
    String getRealPath(String var1);

    int getRemotePort();

    String getLocalName();

    String getLocalAddr();

    int getLocalPort();
}

servletResponse interface:

package javax.servlet;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Enumeration;
import java.util.Locale;
import java.util.Map;

public interface ServletRequest {
    Object getAttribute(String var1);

    Enumeration getAttributeNames();

    String getCharacterEncoding();

    void setCharacterEncoding(String var1) throws UnsupportedEncodingException;

    int getContentLength();

    String getContentType();

    ServletInputStream getInputStream() throws IOException;

    String getParameter(String var1);

    Enumeration getParameterNames();

    String[] getParameterValues(String var1);

    Map getParameterMap();

    String getProtocol();

    String getScheme();

    String getServerName();

    int getServerPort();

    BufferedReader getReader() throws IOException;

    String getRemoteAddr();

    String getRemoteHost();

    void setAttribute(String var1, Object var2);

    void removeAttribute(String var1);

    Locale getLocale();

    Enumeration getLocales();

    boolean isSecure();

    RequestDispatcher getRequestDispatcher(String var1);

    /** @deprecated */
    String getRealPath(String var1);

    int getRemotePort();

    String getLocalName();

    String getLocalAddr();

    int getLocalPort();
}

ServletConfig在Servlet init时由容器传过来。

Servlet如何工作

服务器如何根据URL到达正确地Servlet容器中的。

Servlet中的Listener

Filter如何工作

filter interface:

package javax.servlet;

import java.io.IOException;

public interface Filter {
    void init(FilterConfig var1) throws ServletException;

    void doFilter(ServletRequest var1, ServletResponse var2, FilterChain var3) throws IOException, ServletException;

    void destroy();
}

filterConfig interface:

package javax.servlet;

import java.util.Enumeration;

public interface FilterConfig {
    String getFilterName();

    ServletContext getServletContext();

    String getInitParameter(String var1);

    Enumeration<String> getInitParameterNames();
}

filterChain interface:

package javax.servlet;

import java.io.IOException;

public interface FilterChain {
    void doFilter(ServletRequest var1, ServletResponse var2) throws IOException, ServletException;
}