CISC370-011 -- demo code from class #9

This page provides links to some short snippets of code from class #9 (Nov 4).

Elist.java uses JDBC to build a list of employees and their titles, then formats the result as an HTML file.

PrepStat.java demonstrates a prepared statement.

DbMeta.java uses database metadata to list all tables in a database.

ExecSQL.java is a very simple interactive query tool. It reads its database connection from a property file (using the Java Properties API!) named ExecSQL.properties, then reads SQL commands from standard input and writes their results to standard output. Each command must be terminated by a line containing only the word "GO". To end the program, enter a line containing only the word "quit". Here is a sample session of the program:

D:\CIS370\Web\demo\class09>type ExecSQL.properties
jdbc.drivers=org.hsqldb.jdbcDriver
jdbc.url=jdbc:hsqldb:hsql://localhost:9001
jdbc.username=sa
jdbc.password=

D:\CIS370\Web\demo\class09>java ExecSQL

Enter command (or 'quit' to exit):
select *
from turkey
go

Query is:
select *
from turkey

Output is:
NAME, VALUE
walt, hunk
sharon, babe
paul, bozo
dan, brainiac
fred, flintstone

Enter command (or 'quit' to exit):
create table dingleberry (
	species VARCHAR(32) NOT NULL,
	howMany INT DEFAULT 0
	)
go

Query is:
create table dingleberry (
	species VARCHAR(32) NOT NULL,
	howMany INT DEFAULT 0
	)

No output.

Enter command (or 'quit' to exit):
insert into dingleberry(species,howMany) values('Chickadee',17)
insert into dingleberry(species,howMany) values('Titmouse',12)
insert into dingleberry(species,howMany) values('Cardinal',20)
insert into dingleberry(species,howMany) values('Goldfinch',5)
go

Query is:
insert into dingleberry(species,howMany) values('Chickadee',17)
insert into dingleberry(species,howMany) values('Titmouse',12)
insert into dingleberry(species,howMany) values('Cardinal',20)
insert into dingleberry(species,howMany) values('Goldfinch',5)

No output.

Enter command (or 'quit' to exit):
select sum(howMany)
from dingleberry
go

Query is:
select sum(howMany)
from dingleberry

Output is:
HOWMANY
54

Enter command (or 'quit' to exit):
quit

D:\CIS370\Web\demo\class09>

EmployeeList.java is a simple servlet that returns an employee list formatted as an HTML document.

ImageTest.java illustrates how a servlet (or a CGI script) can return a document of type other than HTML (in this case, a PNG image). Note the use of the excellent JFreeChart plotting library. A screen dump of this servlet's output is: