package org.expressme.webwind.demo.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.expressme.webwind.demo.Post;
import org.expressme.webwind.demo.tx.TxHolder;
public class DbUtils {
public static final String FIRST_POST_TITLE = "My first blog post";
public static final String FIRST_POST_CONTENT = "Hello, this is my first blog post!";
public static Connection getConnection() throws SQLException {
return DriverManager.getConnection("jdbc:hsqldb:mem:test", "sa", "");
}
private static long nextId;
public static long nextId() {
nextId++;
return nextId;
}
public static void initDb() throws SQLException {
try {
Class.forName("org.hsqldb.jdbcDriver");
}
catch(ClassNotFoundException e) {
throw new NoClassDefFoundError("org.hsqldb.jdbcDriver");
}
Connection conn = getConnection();
execute(conn, "drop table Post if exists");
execute(conn, "create table Post (id bigint primary key, title varchar(50) not null, content varchar(2000) not null, creation date not null)");
execute(conn, "insert into Post (id, title, content, creation) values(?, ?, ?, ?)", 0, FIRST_POST_TITLE, FIRST_POST_CONTENT, new Date());
conn.close();
}
static void execute(Connection conn, String sql, Object... args) throws SQLException {
PreparedStatement ps = conn.prepareStatement(sql);
for (int i=0; i<args.length; i++) {
Object o = args[i];
ps.setObject(i+1, o);
}
ps.executeUpdate();
ps.close();
}
public static List<Post> queryForList(String sql, Object... args) throws Exception {
Connection conn = TxHolder.getCurrentConnection();
PreparedStatement ps = null;
ResultSet rs = null;
List<Post> list = new ArrayList<Post>();
try {
ps = conn.prepareStatement(sql);
bindParameters(ps, args);
rs = ps.executeQuery();
while (rs.next()) {
Post post = new Post(rs.getLong("id"), rs.getString("title"), rs.getString("content"), rs.getDate("creation"));
list.add(post);
}
return list;
}
finally {
close(rs);
close(ps);
}
}
public static int executeUpdate(String sql, Object... args) throws Exception {
Connection conn = TxHolder.getCurrentConnection();
PreparedStatement ps = null;
try {
ps = conn.prepareStatement(sql);
bindParameters(ps, args);
return ps.executeUpdate();
}
finally {
close(ps);
}
}
static void bindParameters(PreparedStatement ps, Object... args) throws Exception {
for (int i=0; i<args.length; i++) {
ps.setObject(i+1, args[i]);
}
}
static void close(PreparedStatement ps) {
if (ps!=null) {
try {
ps.close();
}
catch (SQLException e) {}
}
}
static void close(ResultSet rs) {
if (rs!=null) {
try {
rs.close();
}
catch (SQLException e) {}
}
}
}