example/datestyle.class\

example/psql.class\

example/ImageViewer.class\

example/metadata.class

example/metadata.class\

example/threadsafe.class

@echo" example.psql Simple java implementation of psql"

@echo" example.Objects Demonstrates Object Serialisation"

@echo""

@echo These are not really examples, but tests various parts of the driver

@echo" example.metadata Tests various metadata methods"

@echo" example.threadsafe Tests the driver's thread safety"

@echo ------------------------------------------------------------

@echo

example/psql.class:example/psql.java

example/ImageViewer.class:example/ImageViewer.java

example/metadata.class:example/metadata.java

packageexample;

importjava.io.*;

importjava.sql.*;

importjava.text.*;

importpostgresql.largeobject.*;

{

Connectiondb;// The connection to the database

Statementst;// Our statement to run queries with

publicthreadsafe(Stringargs[])throwsClassNotFoundException,FileNotFoundException,IOException,SQLException

{

Stringurl =args[0];

Stringusr =args[1];

Stringpwd =args[2];

Class.forName("postgresql.Driver");

System.out.println("Connecting to Database URL = " +url);

db =DriverManager.getConnection(url,usr,pwd);

System.out.println("Connected...Now creating a statement");

st =db.createStatement();

cleanup();

doexample();

cleanup();

System.out.println("Now closing the connection");

st.close();

db.close();

}

publicvoidcleanup()

{

try {

st.executeUpdate("drop table basic");

}catch(Exceptionex) {

}

}

publicvoiddoexample()throwsSQLException

{

System.out.println("\nThis test runs three Threads. Two simply insert data into a table, then\nthey perform a query. While they are running, a third thread is running,\nand it load data into, then reads from a Large Object.\n\nIf alls well, this should run without any errors. If so, we are Thread Safe.\nWhy test JDBC & LargeObject's? Because both will run over the network\nconnection, and if locking on the stream isn't done correctly, the backend\nwill get pretty confused!\n");

thread3thread3=null;

try {

Threadthread0 =Thread.currentThread();

Threadthread1 =newthread1(db);

Threadthread2 =newthread2(db);

thread3 =newthread3(db);

thread1.start();

thread2.start();

thread3.start();

System.out.println("Waiting for threads to run");

while(thread1.isAlive() ||thread2.isAlive() ||thread3.isAlive())

thread0.yield();

}finally {

if(thread3 !=null)

thread3.cleanup();

}

System.out.println("No Exceptions have been thrown. This is a good omen, as it means that we are\npretty much thread safe as we can get.");

}

{

Connectionc;

Statementst;

publicthread1(Connectionc)throwsSQLException {

this.c =c;

st =c.createStatement();

}

publicvoidrun() {

try {

System.out.println("Thread 1 running...");

st.executeUpdate("create table basic (a int2, b int2)");

st.executeUpdate("insert into basic values (1,1)");

st.executeUpdate("insert into basic values (2,1)");

st.executeUpdate("insert into basic values (3,1)");

PreparedStatementps =db.prepareStatement("insert into basic values (?,?)");

for(inti=2;i<200;i++) {

ps.setInt(1,4);// "column a" = 5

ps.setInt(2,i);// "column b" = i

ps.executeUpdate();// executeUpdate because insert returns no data

if((i%50)==0)

DriverManager.println("Thread 1 done "+i+" inserts");

}

ps.close();// Always close when we are done with it

DriverManager.println("Thread 1 performing a query");

ResultSetrs =st.executeQuery("select a, b from basic");

intcnt=0;

if(rs!=null) {

while(rs.next()) {

inta =rs.getInt("a");// This shows how to get the value by name

intb =rs.getInt(2);// This shows how to get the value by column

cnt++;

}

rs.close();// again, you must close the result when done

}

DriverManager.println("Thread 1 read "+cnt+" rows");

System.out.println("Thread 1 finished");

}catch(SQLExceptionse) {

System.err.println("Thread 1: "+se.toString());

se.printStackTrace();

System.exit(1);

}

}

}

{

Connectionc;

Statementst;

publicthread2(Connectionc)throwsSQLException {

this.c =c;

st =c.createStatement();

}

publicvoidrun() {

try {

System.out.println("Thread 2 running...");

PreparedStatementps =db.prepareStatement("insert into basic values (?,?)");

for(inti=2;i<200;i++) {

ps.setInt(1,4);// "column a" = 5

ps.setInt(2,i);// "column b" = i

ps.executeUpdate();// executeUpdate because insert returns no data

if((i%50)==0)

DriverManager.println("Thread 2 done "+i+" inserts");

}

ps.close();// Always close when we are done with it

DriverManager.println("Thread 2 performing a query");

ResultSetrs =st.executeQuery("select * from basic where b>1");

intcnt=0;

if(rs!=null) {

intcol_a =rs.findColumn("a");

intcol_b =rs.findColumn("b");

while(rs.next()) {

inta =rs.getInt(col_a);// This shows how to get the value by name

intb =rs.getInt(col_b);// This shows how to get the value by column

cnt++;

}

rs.close();// again, you must close the result when done

}

DriverManager.println("Thread 2 read "+cnt+" rows");

System.out.println("Thread 2 finished");

}catch(SQLExceptionse) {

System.err.println("Thread 2: "+se.toString());

se.printStackTrace();

System.exit(1);

}

}

}

{

Connectionc;

Statementst;

LargeObjectManagerlom;

LargeObjectlo;

intoid;

publicthread3(Connectionc)throwsSQLException {

this.c =c;

lom = ((postgresql.Connection)c).getLargeObjectAPI();

oid =lom.create();

System.out.println("Thread 3 has created a blob of oid "+oid);

}

publicvoidrun() {

try {

System.out.println("Thread 3 running...");

DriverManager.println("Thread 3: Loading data into blob "+oid);

lo =lom.open(oid);

FileInputStreamfis =newFileInputStream("example/threadsafe.java");

bytebuf[] =newbyte[128];

intrc,bc=1,bs=0;

while((rc=fis.read(buf))>0) {

DriverManager.println("Thread 3 read block "+bc+" "+bs+" bytes");

lo.write(buf,0,rc);

bc++;

bs+=rc;

}

lo.close();

fis.close();

DriverManager.println("Thread 3: Reading blob "+oid);

lo=lom.open(oid);

bc=0;

while(buf.length>0) {

buf=lo.read(buf.length);

if(buf.length>0) {

Strings =newString(buf);

bc++;

DriverManager.println("Thread 3 block "+bc);

DriverManager.println("Block "+bc+" got "+s);

}

}

lo.close();

System.out.println("Thread 3 finished");

}catch(Exceptionse) {

System.err.println("Thread 3: "+se.toString());

se.printStackTrace();

System.exit(1);

}

}

publicvoidcleanup()throwsSQLException {

if(lom!=null &&oid!=0) {

System.out.println("Thread 3: Removing blob oid="+oid);

lom.delete(oid);

}

}

}

publicstaticvoidinstructions()

{

System.out.println("\nThis tests the thread safety of the driver.\n\nThis is done in two parts, the first with standard JDBC calls, and the\nsecond mixing FastPath and LargeObject calls with queries.\n");

System.out.println("Useage:\n java example.threadsafe jdbc:postgresql:database user password [debug]\n\nThe debug field can be anything. It's presence will enable DriverManager's\ndebug trace. Unless you want to see screens of items, don't put anything in\nhere.");

System.exit(1);

}

publicstaticvoidmain(Stringargs[])

{

System.out.println("PostgreSQL Thread Safety test v6.4 rev 1\n");

if(args.length<3)

instructions();

if(args.length>3)

DriverManager.setLogStream(System.err);

try {

threadsafetest =newthreadsafe(args);

}catch(Exceptionex) {

System.err.println("Exception caught.\n"+ex);

ex.printStackTrace();

}

}

}