e1039. logging a message in a servlet.txt

这里面包含了一百多个JAVA源文件

The servlet container provides a simple logging facility for a servlet to log text messages and exceptions. For a more full-featured logging facility, see the java.util.logging package. 
    // See also e1035 The Quintessential Servlet
    
    // Add an entry to the log file
    getServletContext().log("A message");
    
    try {
        // ...
    } catch (Exception e) {
        // Add an entry to the log file and include an exception
        getServletContext().log("An exception occurred", e);
    }

Here's a sample of the log entries in Tomcat: 
    2002-07-06 21:12:54 A message
    2002-07-06 21:12:54 An exception occurred
    java.io.IOException
            at com.mycompany.MyServlet.doGet(Unknown Source)
            at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
            at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
            ...