How do I use Hibernate’s Restriction.in criterion?

By I Wayan Saryada in Hibernate 0 Comment

This example demonstrate the use of Hibernate’s Restriction.in criterion. This restriction will query for some record based on a collection of parameter defined for a specific property of the bean.

package org.kodejava.hibernate;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.HibernateException;
import org.hibernate.Criteria;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Restrictions;
import org.kodejava.hibernate.model.Genre;

import java.util.List;

public class RestrictionInDemo {
    public static Session getSession() throws HibernateException {
        String cfg = "hibernate.cfg.xml";
        SessionFactory sessionFactory = new Configuration().configure(cfg)
                .buildSessionFactory();
        return sessionFactory.openSession();
    }

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        try (Session session = getSession()) {
            // Create a Criteria an add an in constraint for the property
            // id. This in restrictions will return genre with id 1, 2, 3
            // and 4.
            Criteria criteria = session.createCriteria(Genre.class)
                    .add(Restrictions.in("id", 1L, 2L, 3L, 4L));

            List<Genre> result = criteria.list();
            for (Genre genre : result) {
                System.out.println(genre);
            }
        }
    }
}

Maven Dependencies

<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.6.9.Final</version>
    </dependency>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.0.33</version>
    </dependency>
</dependencies>

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How do I create temporary file?

By I Wayan Saryada in Core API, IO 0 Comment

A temporary file can be created by using java.io.File.createTempFile() method. It accepts the prefix, suffix and the path where the file will be stored. When no path is specified it will use the platform default temporary folder.

The name of the temporary file will be in the form of prefix plus five or more random characters plus the suffix. When the suffix is null a default .tmp will be used for suffix.

package org.kodejava.io;

import java.io.File;
import java.io.BufferedWriter;
import java.io.FileWriter;

public class TemporaryFileDemo {
    public static void main(String[] args) throws Exception {
        // Create a temporary file userlist.txt in the default platform
        // temporary folder / directory. We can get the platform temporary
        // folder using System.getProperty("java.io.tmpdir")
        File user = File.createTempFile("userlist", ".txt");

        // Delete the file when the virtual machine is terminated.
        user.deleteOnExit();

        // Create a temporary file data.txt in the user specified folder.
        File data = File.createTempFile("data", ".txt", new File("F:/Temp/Data"));
        data.deleteOnExit();

        // Write data into temporary file
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(data))) {
            writer.write("750101,2008-01-01,BLUE,CAR");
            writer.write("750102,2008-09-06,RED,CAR");
            writer.write("750103,2008-05-01,GREEN,CAR");
            writer.write("750104,2008-06-08,YELLOW,CAR");
        }
    }
}

How do I add hours, minutes or seconds to a date?

By I Wayan Saryada in Core API, Util Package 0 Comment

This example shows you how to add or subtract hours, minutes or seconds to a date using the java.util.Calendar object.

package org.kodejava.util;

import java.util.Calendar;

public class DateAddSubtract {
    public static void main(String[] args) {
        // Gets a calendar using the default time zone and locale. The
        // Calendar returned is based on the current time in the default
        // time zone with the default locale.
        Calendar calendar = Calendar.getInstance();
        System.out.println("Original = " + calendar.getTime());

        // Subtract 2 hour from the current time
        calendar.add(Calendar.HOUR, -2);

        // Add 30 minutes to the calendar time
        calendar.add(Calendar.MINUTE, 30);

        // Add 300 seconds to the calendar time
        calendar.add(Calendar.SECOND, 300);
        System.out.println("Updated  = " + calendar.getTime());
    }
}

The output of the code snippet:

Original = Wed Oct 06 19:47:53 CST 2021
Updated  = Wed Oct 06 18:22:53 CST 2021

How do I add query string to HttpMethod object?

By I Wayan Saryada in Apache Commons, Commons HttpClient 0 Comment

To send query string information in HTTP GET command you either using passing a simple string or an array of NameValuePair object into the HttpMethod‘s setQueryString() method. We also need to encode the parameter values before passing it to the method.

package org.kodejava.commons.httpclient;

import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.util.URIUtil;
import org.apache.commons.httpclient.methods.GetMethod;

import java.io.IOException;

public class SendingQueryParameter {
    public static void main(String[] args) {
        HttpClient client = new HttpClient();
        HttpMethod method = new GetMethod("http://localhost:8080/hello.jsp");

        try {
            // Set query string information for accessing the page using a
            // simple string information.
            method.setQueryString(URIUtil.encodeQuery("catid=10&page=1"));
            client.executeMethod(method);

            // Other cleaner alternative is to use the NameValuePair object to
            // define the parameters for an HTTP GET method.
            NameValuePair param1 = new NameValuePair("catid", URIUtil.encodeQuery("20"));
            NameValuePair param2 = new NameValuePair("page", URIUtil.encodeQuery("2"));
            NameValuePair[] params = new NameValuePair[]{param1, param2};
            method.setQueryString(params);
            client.executeMethod(method);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            method.releaseConnection();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>commons-httpclient</groupId>
    <artifactId>commons-httpclient</artifactId>
    <version>3.1</version>
</dependency>

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How do I set a proxy for HttpClient?

By I Wayan Saryada in Apache Commons, Commons HttpClient 3 Comments

In this example you will see how to configure proxy when using the Apache Commons HttpClient library.

package org.kodejava.commons.httpclient;

import org.apache.commons.httpclient.Credentials;
import org.apache.commons.httpclient.HostConfiguration;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.UsernamePasswordCredentials;
import org.apache.commons.httpclient.auth.AuthScope;
import org.apache.commons.httpclient.methods.GetMethod;

import java.io.IOException;

public class HttpGetProxy {
    private static final String PROXY_HOST = "proxy.host.com";
    private static final int PROXY_PORT = 8080;

    public static void main(String[] args) {
        HttpClient client = new HttpClient();
        HttpMethod method = new GetMethod("https://kodejava.org");

        HostConfiguration config = client.getHostConfiguration();
        config.setProxy(PROXY_HOST, PROXY_PORT);

        String username = "guest";
        String password = "s3cr3t";
        Credentials credentials = new UsernamePasswordCredentials(username, password);
        AuthScope authScope = new AuthScope(PROXY_HOST, PROXY_PORT);

        client.getState().setProxyCredentials(authScope, credentials);

        try {
            client.executeMethod(method);

            if (method.getStatusCode() == HttpStatus.SC_OK) {
                String response = method.getResponseBodyAsString();
                System.out.println("Response = " + response);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            method.releaseConnection();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>commons-httpclient</groupId>
    <artifactId>commons-httpclient</artifactId>
    <version>3.1</version>
</dependency>

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