JDBC PreparedStatement.setMaxRows() affects other objects intantiated from this class and it's parent class

Jason Southern (southern(at)heymax(dot)com) reports a bug with a severity of 2
The lower the number the more severe it is.

Short Description
JDBC PreparedStatement.setMaxRows() affects other objects intantiated from this class and it's parent class

Long Description
============================================================================
POSTGRESQL BUG REPORT TEMPLATE
============================================================================
Your name : Jason Southern
Your email address : southern(at)heymax(dot)com

System Configuration
----------------------
Architecture (example: Intel Pentium) : 600MHz Intel Pentium III, 256MB RAM

Operating System (example: Linux 2.0.26 ELF) : Linux 2.2.16 RedHat 6.2

PostgreSQL version (example: PostgreSQL-6.3) : PostgreSQL-7.0.2

Compiler used (example: gcc 2.7.2) : gcc 2.96

JDBC Driver Version: 7.0.x (jdbc7.0-1.2.jar)

JVM: Sun JVM 1.3

Short Description
-------------------------------------------------
The PreparedStatement.setMaxRows() method affects the max row property of other objects instantiated from the statement class and it's subclasses.

Please describe a way to repeat the problem. Please try to provide a
concise reproducible example, if at all possible:
-----------------------------------------------------------------------
You can reproduce this behavior by loading a PostgreSQL instance with the DDL/DML script below and then compiling and running the class file below.

I would have expected the setMaxRows method to only affect the object on which executed not an entire family of objects.

Table for reproducing bug
-----------------------------------------------------------------------
CREATE TABLE FRUIT (
id_fruit INTEGER,
name VARCHAR(15)
);

INSERT INTO FRUIT VALUES (1, 'apple');
INSERT INTO FRUIT VALUES (2, 'banana');
INSERT INTO FRUIT VALUES (3, 'orange');
INSERT INTO FRUIT VALUES (4, 'kumquat');
INSERT INTO FRUIT VALUES (5, 'nectarine');
INSERT INTO FRUIT VALUES (6, 'pear');
INSERT INTO FRUIT VALUES (7, 'peach');
INSERT INTO FRUIT VALUES (8, 'cantaloupe');
INSERT INTO FRUIT VALUES (9, 'grape');
INSERT INTO FRUIT VALUES (10, 'grapefruit');
INSERT INTO FRUIT VALUES (11, 'avacado');
INSERT INTO FRUIT VALUES (12, 'tomato');
INSERT INTO FRUIT VALUES (13, 'kiwi');
INSERT INTO FRUIT VALUES (14, 'watermelon');
INSERT INTO FRUIT VALUES (15, 'guava');

Sample Code
import java.sql.*;

public class MaxRowTest {
private static Connection conn;
private static final String DB_INSTANCE = "";
private static final String DB_USERNAME = "";
private static final String DB_PASSWORD = "";

public static void main(String[] a) throws Exception {
String sqlStmt;
ResultSet rst;
int rowCount = 0;
Statement stmt = null;
Statement stmt2 = null;
PreparedStatement preStmt = null;
PreparedStatement preStmt2 = null;

System.out.println("About to connect to database...");
connectToDatabase();
System.out.println("Connected to database...");

stmt = conn.createStatement();
stmt2 = conn.createStatement();

System.out.println("Creating prepared statement...");
sqlStmt = "SELECT id_fruit, name FROM FRUIT WHERE id_fruit < ? ORDER BY name";
preStmt = conn.prepareStatement(sqlStmt);
preStmt2 = conn.prepareStatement(sqlStmt);

System.out.println("Setting max rows to 5 on this prepared statement...");
preStmt.setMaxRows(5);

System.out.println("Setting argument on prepared statement to return all");
System.out.println("fruit whose id is less than 10...");
preStmt.setInt(1, 10);

System.out.println("About to execute statement.");
System.out.println("Expecting 5 rows...");
rst = preStmt.executeQuery();
rowCount = 0;

while (rst.next()) {
rowCount++;
}
System.out.println("Prepared statement returned ResultSet with " + rowCount + " fruit in it");

System.out.println("\nUsing second prepared statement object...");
System.out.println("Setting argument on prepared statement to return all");
System.out.println("fruit whose id is less than 10...");
preStmt.setInt(1, 10);

System.out.println("About to execute statement.");
System.out.println("Expecting 9 rows...");
rst = preStmt.executeQuery();
rowCount = 0;

while (rst.next()) {
rowCount++;
}
System.out.println("Prepared statement 2 returned " + rowCount + " fruit");

System.out.println("\nAbout to run query to select all fruit from table.");
System.out.println("Expecting 15 rows...");
sqlStmt = "SELECT id_fruit, name FROM FRUIT ORDER BY name";
rst = stmt.executeQuery(sqlStmt);
rowCount = 0;

while (rst.next()) {
rowCount++;
}
System.out.println("Statement returned ResultSet with " + rowCount + " fruit in it");

System.out.println("\nAbout to run query to select all fruit using second statement object.");
System.out.println("Expecting 15 rows...");
sqlStmt = "SELECT id_fruit,name FROM FRUIT ORDER BY name";
rst = stmt2.executeQuery(sqlStmt);
rowCount = 0;

while (rst.next()) {
rowCount++;
}
System.out.println("Statement 2 returned " + rowCount + " fruit");

System.out.println("\nSetting max rows to 0 on statement object...\n");
stmt.setMaxRows(0);

System.out.println("About to run query to select all fruit from table.");
System.out.println("Expecting 15 rows...");
sqlStmt = "SELECT id_fruit, name FROM FRUIT ORDER BY name";
rst = stmt.executeQuery(sqlStmt);
rowCount = 0;

while (rst.next()) {
rowCount++;
}
System.out.println("Statement returned ResultSet with " + rowCount + " fruit in it");

System.out.println("\nAbout to run query to select all fruit using second statement object.");
System.out.println("Expecting 15 rows...");
sqlStmt = "SELECT id_fruit, name FROM FRUIT ORDER BY name";
rst = stmt2.executeQuery(sqlStmt);
rowCount = 0;

while (rst.next()) {
rowCount++;
}
System.out.println("Statement 2 returned " + rowCount + " fruit");

System.out.println("\nSetting argument on prepared statement to return all");
System.out.println("fruit whose id is less than 12...");
preStmt.setInt(1, 12);

System.out.println("About to execute statement.");
System.out.println("Expecting 5 rows...");
rst = preStmt.executeQuery();
rowCount = 0;

while (rst.next()) {
rowCount++;
}
System.out.println("Prepared statement returned ResultSet with " + rowCount + " fruit in it");

System.out.println("\nUsing second prepared statement object...");
System.out.println("Setting argument on prepared statement to return all");
System.out.println("fruit whose id is less than 10...");
preStmt.setInt(1, 10);

System.out.println("About to execute statement.");
System.out.println("Expecting 9 rows...");
rst = preStmt.executeQuery();
rowCount = 0;

while (rst.next()) {
rowCount++;
}
System.out.println("Prepared statement 2 returned " + rowCount + " fruit");

// Close statement objects
if (preStmt != null) {
preStmt.close();
}
if (stmt != null) {
stmt.close();
}
}

private static void connectToDatabase() throws Exception {
try {
try {
Class.forName("org.postgresql.Driver");
} catch (ClassNotFoundException e) {
throw new Exception("Unable to locate PostgreSQL driver. Make sure the driver is installed and and appears in CLASSPATH.");
}
conn = DriverManager.getConnection(DB_INSTANCE, DB_USERNAME, DB_PASSWORD);
conn.setAutoCommit(false);
conn.setTransactionIsolation(conn.TRANSACTION_READ_COMMITTED);
} catch (SQLException e) {
throw new Exception("connectToDatabase(): [SQLException] " + e);
}
}

protected void finalize() {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {}
}
}
}

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