How do I format number as percentage string?

By Wayan in Core API, Text Package 0 Comment

The NumberFormat.getPercentInstance() method returns a percentage format for the specified locale. In this example we will format the number as percentage using the Locale.US locale.

package org.kodejava.text;

import java.text.NumberFormat;
import java.util.Locale;

public class LocalePercentageFormat {
    public static void main(String[] args) {
        // Format percentage for Locale.US locale with this formatter,
        // a decimal fraction such as 0.75 is displayed as 75%
        double number = 0.25;
        NumberFormat format = NumberFormat.getPercentInstance(Locale.US);
        String percentage = format.format(number);
        System.out.println(number + " in percentage = " + percentage);
    }
}

The following line is the output of the program:

0.25 in percentage = 25%

How do I format a number as currency string?

By Wayan in Core API, Text Package 6 Comments

Creating a financial application requires you to format number as a currency. It should include the correct thousand separator, decimal separator and the currency symbol. For this purpose you can use the NumberFormat.getCurrencyInstance() method and pass the correct Locale to get the currency format that you want.

package org.kodejava.text;

import java.text.NumberFormat;
import java.util.Locale;

public class LocaleCurrencyFormat {
    public static void main(String[] args) {
        Double number = 1500D;

        // Format currency for Canada locale in Canada locale, 
        // the decimal point symbol is a comma and currency
        // symbol is $.
        NumberFormat format = NumberFormat.getCurrencyInstance(Locale.CANADA);
        String currency = format.format(number);
        System.out.println("Currency in Canada : " + currency);

        // Format currency for Germany locale in German locale,
        // the decimal point symbol is a dot and currency symbol
        // is €.
        format = NumberFormat.getCurrencyInstance(Locale.GERMANY);
        currency = format.format(number);
        System.out.println("Currency in Germany: " + currency);
    }
}

Here is an output for the currency format using the Locale.CANADA and Locale.GERMANY.

Currency in Canada : $1,500.00
Currency in Germany: 1.500,00 €

How do I create a Locale object using a variant?

By Wayan in Core API, Util Package 0 Comment

Font differences may force you to use different characters on different platforms. You could then define the Locale objects with the variant codes to identify those differences. The variant codes conform to no standard. They are arbitrary and specific to your application. If you create Locale objects with variant codes only your application will know how to deal with them.

In this example instead of demonstrating to use a different font for different platform we simplify it to just print a different message. We create three different resource bundles for each platform, the Birthday_fr_FR_UNIX.properties, Birthday_fr_FR_MAC.properties and Birthday_fr_FR_WIN.properties. These files will contains different message for each platform.

package org.kodejava.util;

import java.util.Locale;
import java.util.ResourceBundle;

public class LocalePlatform {
    public static void main(String[] args) {
        ResourceBundle res;
        String language = "fr";
        String country = "FR";

        // Construct a locale from language, country, variant. Where the variant
        // can be a variant vendor and browser specific code.
        Locale unix = new Locale(language, country, "UNIX");
        res = ResourceBundle.getBundle("Birthday", unix);
        System.out.println("UNIX: " + res.getString("birthday"));

        Locale mac = new Locale(language, country, "MAC");
        res = ResourceBundle.getBundle("Birthday", mac);
        System.out.println("MAC : " + res.getString("birthday"));

        Locale windows = new Locale(language, country, "WIN");
        res = ResourceBundle.getBundle("Birthday", windows);
        System.out.println("WIN : " + res.getString("birthday"));
    }
}

Here are the contents of the resource bundle files:

Birthday_fr_FR_UNIX.properties

birthday=Unix, Joyeux anniversaire à vous!

Birthday_fr_FR_MAC.properties

birthday=Mac, Joyeux anniversaire à vous!

Birthday_fr_FR_WIN.properties

birthday=Windows, Joyeux anniversaire à vous!

How do I get all available Locale language codes?

By Wayan in Core API, Util Package 0 Comment

When you want to internationalize your application, you need to know the language code and country code. These codes will be used as the properties file name (the file name must be ended in language_COUNTRY.properties). Here is an example that show how to get all supported language’s code.

package org.kodejava.util;

import java.util.Locale;

public class LocaleCountryLanguageCode {
    public static void main(String[] args) {
        // Gets an array of all installed locales. The returned array represents
        // the union of locales supported by the Java runtime environment and by 
        // installed LocaleServiceProvider implementations.
        Locale[] locales = Locale.getAvailableLocales();

        for (Locale locale : locales) {
            System.out.printf("Locale name: %s = %s_%s%n",
                    locale.getDisplayName(), locale.getLanguage(), locale.getCountry());
        }
    }
}

Here are some of the results produces by the code above:

...
Locale name: Kikuyu (Latin, Kenya) = ki_KE
Locale name: Spanish (Brazil) = es_BR
Locale name: Koyra Chiini (Mali) = khq_ML
Locale name: English (Solomon Islands) = en_SB
Locale name: Tibetan (Tibetan, China) = bo_CN
Locale name: Cherokee (United States) = chr_US
Locale name: Kinyarwanda (Rwanda) = rw_RW
Locale name: Tachelhit (Tifinagh, Morocco) = shi_MA
Locale name: Arabic (Iraq) = ar_IQ
Locale name: Nyankole = nyn_
...

How do I select records from database using JdbcTemplate?

By Wayan in Spring JDBC 0 Comment

In this example you will learn how to select records from the database using JdbcTemplate.queryForList() method. This method returns a List object which stores information selected from the table in a HashMap object. The key of the map is the table’s field names while the value of the map contains the corresponding table’s field value.

package org.kodejava.spring.jdbc;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DriverManagerDataSource;

import java.util.List;
import java.util.Map;

public class SelectDemo {
    public static void main(String[] args) {
        // Creates a DataSource object.
        DriverManagerDataSource ds = new DriverManagerDataSource();
        ds.setDriverClassName("com.mysql.cj.jdbc.Driver");
        ds.setUrl("jdbc:mysql://localhost/musicdb");
        ds.setUsername("root");
        ds.setPassword("");

        // Creates an instance of JdbcTemplate.
        JdbcTemplate template = new JdbcTemplate(ds);

        // Executes a select query using queryForList() method. This
        // method returns a List containing HashMap object. The key
        // of the map is the table's field name and the value is
        // the table's field value.
        String query = "SELECT * FROM record";
        List<Map<String, Object>> results = template.queryForList(query);
        for (Map<String, Object> result : results) {
            for (String key : result.keySet()) {
                System.out.print(key + " = " + result.get(key) + "; ");
            }
            System.out.println();
        }

    }
}

Maven Dependencies

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>6.1.10</version>
    </dependency>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.4.0</version>
    </dependency>
</dependencies>

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