JavaWeb Learning Summary: Packaging, Tomcat Architecture, Encryption Principles, and HTTPS Connector Configuration

1. Packaging JavaWeb applications: Use the jar command to create a WAR file. Example: packaging the project JavaWebDemoProject into a WAR, then deploy it by copying the WAR into Tomcat’s webapps directory, where Tomcat automatically extracts it on startup.

2. Tomcat architecture: Tomcat starts from server.xml, creating a Server that contains a Service. Each Service defines one or more Connector (e.g., HTTP on port 8080, HTTPS on 8443, AJP on 8009). Connectors forward requests to an Engine, which selects a Host, and each host contains a Context representing a web application.

<?xml version='1.0' encoding='utf-8'?>
<Server port="8005" shutdown="SHUTDOWN">
  <Service name="Catalina">
    <Connector port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" />
    <Connector port="8443" protocol="org.apache.coyote.http11.Http11Protocol" maxThreads="150" SSLEnabled="true" scheme="https" secure="true" clientAuth="false" sslProtocol="TLS" keystoreFile="conf/.keystore" keystorePass="123456" />
    <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />
    <Engine name="Catalina" defaultHost="localhost">
      <Host name="localhost" appBase="webapps" unpackWARs="true" autoDeploy="true">
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log." suffix=".txt" pattern="%h %l %u %t &quot;%r&quot; %s %b" />
      </Host>
      <Host name="www.gacl.cn" appBase="F:\JavaWebApps">
        <Context path="" docBase="F:\JavaWebApps\JavaWebDemo1" />
      </Host>
    </Engine>
  </Service>
</Server>

3. Encryption principles: Symmetric encryption uses a single key for both encryption and decryption (e.g., DES, AES). Asymmetric encryption uses a public‑key/private‑key pair; the public key encrypts data, and only the matching private key can decrypt it. Trust in public keys is established via a Certificate Authority (CA).

4. Generating a self‑signed certificate for Tomcat: Use the JDK keytool utility, e.g., keytool -genkey -alias tomcat -keyalg RSA The command creates a .keystore file containing the certificate. You can list its contents with keytool -list -keystore .keystore.

5. Configuring the HTTPS connector: Copy the generated .keystore to TOMCAT_HOME/conf and add the following Connector element to server.xml:

<Connector port="8443" protocol="org.apache.coyote.http11.Http11Protocol"
           maxThreads="150" SSLEnabled="true" scheme="https" secure="true"
           clientAuth="false" sslProtocol="TLS"
           keystoreFile="conf/.keystore" keystorePass="123456" />

After restarting Tomcat, accessing https://localhost:8443/ will present the self‑signed certificate. Browsers will show a security warning because the certificate is not signed by a trusted CA; the warning can be bypassed for testing purposes. The guide also shows how to install the certificate in Internet Explorer and how to remove it.