How do I know if a database supports scrollable result sets?

By I Wayan Saryada in JDBC 0 Comment 
package org.kodejava.jdbc;

import java.sql.*;

public class SupportScrollableResultSet {
    private static final String URL = "jdbc:mysql://localhost/kodejava";
    private static final String USERNAME = "kodejava";
    private static final String PASSWORD = "s3cr*t";

    public static void main(String[] args) {
        try (Connection connection =
                     DriverManager.getConnection(URL, USERNAME, PASSWORD)) {
            DatabaseMetaData meta = connection.getMetaData();

            boolean isForwardOnly = meta.supportsResultSetType(
                    ResultSet.TYPE_FORWARD_ONLY);
            System.out.println("ForwardOnly = " + isForwardOnly);

            boolean isScrollInsensitive = meta.supportsResultSetType(
                    ResultSet.TYPE_SCROLL_INSENSITIVE);
            System.out.println("ScrollInsensitive = " + isScrollInsensitive);

            boolean isScrollSensitive = meta.supportsResultSetType(
                    ResultSet.TYPE_SCROLL_SENSITIVE);
            System.out.println("ScrollSensitive = " + isScrollSensitive);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

The result of the code snippet above:

ForwardOnly = true
ScrollInsensitive = true
ScrollSensitive = false

Maven Dependencies

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.4.0</version>
</dependency>

Maven Central

How do I know if database support batch update?

By I Wayan Saryada in JDBC 0 Comment 
package org.kodejava.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;

public class BatchSupportChecker {
    private static final String URL = "jdbc:mysql://localhost/kodejava";
    private static final String USERNAME = "kodejava";
    private static final String PASSWORD = "s3cr*t";

    public static void main(String[] args) {
        try (Connection connection =
                     DriverManager.getConnection(URL, USERNAME, PASSWORD)) {
            DatabaseMetaData metadata = connection.getMetaData();

            // Check to see if the database supports batch updates
            boolean isBatchSupported = metadata.supportsBatchUpdates();
            System.out.println("Batch Supported = " + isBatchSupported);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.4.0</version>
</dependency>

Maven Central

How do I create type specific collections?

By I Wayan Saryada in Basic, Core API 0 Comment 
package org.kodejava.basic;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class TypeSpecificCollection {
    public static void main(String[] args) {
        // Using a Generic can enable us to create a type specific collection
        // object. In the example below we create a Map whose key is an Integer
        // a have the value of a String.
        Map<Integer, String> grades = new HashMap<>();
        grades.put(1, "A");
        grades.put(2, "B");
        grades.put(3, "C");
        grades.put(4, "D");
        grades.put(5, "E");

        // A value obtained from type specific collection doesn't need to
        // be cast, it knows the type returned.
        String value = grades.get(1);
        System.out.println("value = " + value);

        // Creating a List that will contain a String only values.
        List<String> dayNames = new ArrayList<>();
        dayNames.add("Sunday");
        dayNames.add("Monday");
        dayNames.add("Tuesday");
        dayNames.add("Wednesday");

        // We also don't need to cast the retrieved value because it knows the
        // returned type object.
        String firstDay = dayNames.get(0);
        System.out.println("firstDay = " + firstDay);
    }
}

How do I get all available timezones?

By I Wayan Saryada in Core API, Util Package 0 Comment 
package org.kodejava.util;

import java.util.TimeZone;

public class TimezonesExample {
    public static void main(String[] args) {
        String[] availableTimezones = TimeZone.getAvailableIDs();

        for (String timezone : availableTimezones) {
            System.out.println("Timezone ID = " + timezone);
        }
    }
}

Some examples of the returned timezones ids are:

Timezone ID = Etc/GMT+12
Timezone ID = Etc/GMT+11
Timezone ID = MIT
Timezone ID = Pacific/Apia
Timezone ID = Pacific/Midway
Timezone ID = Pacific/Niue
Timezone ID = Pacific/Pago_Pago
Timezone ID = Pacific/Samoa
Timezone ID = US/Samoa
...

How do I get data types supported by database?

By I Wayan Saryada in JDBC 0 Comment 
package org.kodejava.jdbc;

import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.ResultSet;

public class DatabaseSupportedType {
    private static final String URL = "jdbc:mysql://localhost/kodejava";
    private static final String USERNAME = "kodejava";
    private static final String PASSWORD = "s3cr*t";

    public static void main(String[] args) {
        try (Connection connection =
                     DriverManager.getConnection(URL, USERNAME, PASSWORD)) {

            DatabaseMetaData metadata = connection.getMetaData();
            ResultSet resultSet = metadata.getTypeInfo();
            while (resultSet.next()) {
                String typeName = resultSet.getString("TYPE_NAME");
                System.out.println("Type Name = " + typeName);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Here are the data types supported by MySQL database:

Type Name = BIT
Type Name = TINYINT
Type Name = TINYINT UNSIGNED
Type Name = BIGINT
Type Name = BIGINT UNSIGNED
Type Name = LONG VARBINARY
Type Name = MEDIUMBLOB
Type Name = LONGBLOB
Type Name = BLOB
Type Name = VARBINARY
Type Name = TINYBLOB
Type Name = BINARY
Type Name = LONG VARCHAR
Type Name = MEDIUMTEXT
Type Name = LONGTEXT
Type Name = TEXT
Type Name = CHAR
Type Name = ENUM
Type Name = SET
Type Name = DECIMAL
Type Name = NUMERIC
Type Name = INTEGER
Type Name = INT
Type Name = MEDIUMINT
Type Name = INTEGER UNSIGNED
Type Name = INT UNSIGNED
Type Name = MEDIUMINT UNSIGNED
Type Name = SMALLINT
Type Name = SMALLINT UNSIGNED
Type Name = FLOAT
Type Name = DOUBLE
Type Name = DOUBLE PRECISION
Type Name = REAL
Type Name = DOUBLE UNSIGNED
Type Name = DOUBLE PRECISION UNSIGNED
Type Name = VARCHAR
Type Name = TINYTEXT
Type Name = BOOL
Type Name = DATE
Type Name = YEAR
Type Name = TIME
Type Name = DATETIME
Type Name = TIMESTAMP

Maven Dependencies

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.4.0</version>
</dependency>

Maven Central