Java/Hibernate/Hibernate Filter
Hibernate Filter Demo
<source lang="java">
///////////////////////////////////////////////////////////////////////// import java.util.*; import java.sql.*; import org.hibernate.*; import org.hibernate.cfg.*; import org.hibernate.criterion.*; public class Main {
public static void main(String[] args) {
HibernateUtil.setup("create table User ( id int, username VARCHAR, activated boolean);");
//insert the users
insertUser("a",true);
insertUser("b",true);
insertUser("c",false);
insertUser("e",false);
insertUser("e",false);
SessionFactory factory = new Configuration().configure().buildSessionFactory();
Session session = factory.openSession();
Transaction tx = session.beginTransaction();
//Show all users
System.out.println("ALL USERS");
displayUsers(session);
//Show activated users
Filter filter = session.enableFilter("activatedFilter");
filter.setParameter("activatedParam",new Boolean(true));
System.out.println("ACTIVATED USERS");
displayUsers(session);
//Show non-activated users
filter.setParameter("activatedParam",new Boolean(false));
System.out.println("NON-ACTIVATED USERS");
displayUsers(session);
session.close();
HibernateUtil.checkData("select * from User");
}
public static void displayUsers(Session session)
{
Transaction trans = session.beginTransaction();
Query query = session.createQuery("from User");
Iterator results = query.iterate();
while (results.hasNext())
{
User user = (User) results.next();
System.out.print(user.getUsername() + " is ");
if (user.isActivated())
{
System.out.println("activated.");
}
else
{
System.out.println("not activated.");
}
}
trans.rumit();
}
public static void insertUser(String name, boolean activated)
{
Session session = HibernateUtil.currentSession();
Transaction trans = session.beginTransaction();
User user = new User();
user.setUsername(name);
user.setActivated(activated);
session.save(user);
trans.rumit();
}
}
///////////////////////////////////////////////////////////////////////// <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="User">
<id name="id" type="int">
<generator class="increment"/>
</id>
<property name="username" type="string" length="32"/>
<property name="activated" type="boolean"/>
<filter name="activatedFilter" condition=":activatedParam = activated"/>
</class>
<filter-def name="activatedFilter">
<filter-param name="activatedParam" type="boolean"/>
</filter-def>
</hibernate-mapping>
///////////////////////////////////////////////////////////////////////// public class User {
private int id;
private String username;
private boolean activated;
public boolean isActivated()
{
return activated;
}
public void setActivated(boolean activated)
{
this.activated = activated;
}
public int getId()
{
return id;
}
public void setId(int id)
{
this.id = id;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
}
///////////////////////////////////////////////////////////////////////// import java.sql.Connection; import java.sql.DriverManager; import java.sql.Statement; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import org.hibernate.HibernateException; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; public class HibernateUtil {
public static final SessionFactory sessionFactory;
static {
try {
// Create the SessionFactory from hibernate.cfg.xml
sessionFactory = new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static final ThreadLocal session = new ThreadLocal();
public static Session currentSession() throws HibernateException {
Session s = (Session) session.get();
// Open a new Session, if this thread has none yet
if (s == null) {
s = sessionFactory.openSession();
// Store it in the ThreadLocal variable
session.set(s);
}
return s;
}
public static void closeSession() throws HibernateException {
Session s = (Session) session.get();
if (s != null)
s.close();
session.set(null);
}
static Connection conn;
static Statement st;
public static void setup(String sql) {
try {
// Step 1: Load the JDBC driver.
Class.forName("org.hsqldb.jdbcDriver");
System.out.println("Driver Loaded.");
// Step 2: Establish the connection to the database.
String url = "jdbc:hsqldb:data/tutorial";
conn = DriverManager.getConnection(url, "sa", "");
System.out.println("Got Connection.");
st = conn.createStatement();
st.executeUpdate(sql);
} catch (Exception e) {
System.err.println("Got an exception! ");
e.printStackTrace();
System.exit(0);
}
}
public static void checkData(String sql) {
try {
HibernateUtil.outputResultSet(st
.executeQuery(sql));
// conn.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void outputResultSet(ResultSet rs) throws Exception{
ResultSetMetaData metadata = rs.getMetaData();
int numcols = metadata.getColumnCount();
String[] labels = new String[numcols];
int[] colwidths = new int[numcols];
int[] colpos = new int[numcols];
int linewidth;
linewidth = 1;
for (int i = 0; i < numcols; i++) {
colpos[i] = linewidth;
labels[i] = metadata.getColumnLabel(i + 1); // get its label
int size = metadata.getColumnDisplaySize(i + 1);
if (size > 30 || size == -1)
size = 30;
int labelsize = labels[i].length();
if (labelsize > size)
size = labelsize;
colwidths[i] = size + 1; // save the column the size
linewidth += colwidths[i] + 2; // increment total size
}
StringBuffer divider = new StringBuffer(linewidth);
StringBuffer blankline = new StringBuffer(linewidth);
for (int i = 0; i < linewidth; i++) {
divider.insert(i, "-");
blankline.insert(i, " ");
}
// Put special marks in the divider line at the column positions
for (int i = 0; i < numcols; i++)
divider.setCharAt(colpos[i] - 1, "+");
divider.setCharAt(linewidth - 1, "+");
// Begin the table output with a divider line
System.out.println(divider);
// The next line of the table contains the column labels.
// Begin with a blank line, and put the column names and column
// divider characters "|" into it. overwrite() is defined below.
StringBuffer line = new StringBuffer(blankline.toString());
line.setCharAt(0, "|");
for (int i = 0; i < numcols; i++) {
int pos = colpos[i] + 1 + (colwidths[i] - labels[i].length()) / 2;
overwrite(line, pos, labels[i]);
overwrite(line, colpos[i] + colwidths[i], " |");
}
System.out.println(line);
System.out.println(divider);
while (rs.next()) {
line = new StringBuffer(blankline.toString());
line.setCharAt(0, "|");
for (int i = 0; i < numcols; i++) {
Object value = rs.getObject(i + 1);
overwrite(line, colpos[i] + 1, value.toString().trim());
overwrite(line, colpos[i] + colwidths[i], " |");
}
System.out.println(line);
}
System.out.println(divider);
}
static void overwrite(StringBuffer b, int pos, String s) {
int len = s.length();
for (int i = 0; i < len; i++)
b.setCharAt(pos + i, s.charAt(i));
}
}
</source>
