Driver (Java SE 21 & JDK 21) の使い方まとめです。
だいたいのメソッドを網羅済みです。
API仕様書のおともにどうぞ。
概要
すべてのドライバ・クラスが実装しなければならないインタフェースです。
Driver は、JDBCのドライバを表すインタフェースです。
補足
- JDBCのドライバには Apache Derby を使っています。
Apache Derby は、古い JDK に含まれていたこともありましたが、最新の JDK には含まれていません。
final var driver = DriverManager.getDriver("jdbc:derby:");
System.out.println("-- driver --");
System.out.println("package : " + driver.getClass().getPackage().getName());
System.out.println("major version : " + driver.getMajorVersion());
System.out.println("minor version : " + driver.getMinorVersion());
// 結果
// ↓
//-- driver --
//package : org.apache.derby.iapi.jdbc
//major version : 10
//minor version : 17
record Product(String name, int stock) {
}
final var products = List.of(
new Product("Orange", 10),
new Product("Banana", 20),
new Product("Apple", 30)
);
final var protocol = "jdbc:derby:";
final var driver = DriverManager.getDriver(protocol);
final var url = protocol + "memory:db";
final var properties = new Properties();
properties.setProperty("create", "true");
try (final var connection = driver.connect(url, properties)) {
System.out.println("-- create table --");
try (final var statement = connection.createStatement()) {
final var ret = statement.executeUpdate("""
CREATE TABLE products (
name VARCHAR(20),
stock INTEGER
)
""");
System.out.println("ret = " + ret);
}
System.out.println("-- insert --");
try (final var statement = connection.prepareStatement("""
INSERT INTO products VALUES( ?, ? )
""")) {
for (final var product : products) {
statement.setString(1, product.name());
statement.setInt(2, product.stock());
final var ret = statement.executeUpdate();
System.out.println("ret = " + ret);
}
}
System.out.println("-- select --");
try (final var statement = connection.createStatement()) {
final var result = statement.executeQuery("""
SELECT * FROM products
""");
while (result.next()) {
final var name = result.getString("name");
final var stock = result.getInt("stock");
System.out.println(name + " : " + stock);
}
}
// 結果
// ↓
//-- create table --
//ret = 0
//-- insert --
//ret = 1
//ret = 1
//ret = 1
//-- select --
//Orange : 10
//Banana : 20
//Apple : 30
}
メソッド
boolean acceptsURL (String url)
指定されたURLに接続できるとドライバが判断するかどうかを取得します。
final var protocol = "jdbc:derby:";
final var driver = DriverManager.getDriver(protocol);
final var path = Path.of("R:", "java-work", "db");
final var url = protocol + path;
System.out.println(url); // jdbc:derby:R:\java-work\db
final var ret = driver.acceptsURL(url);
System.out.println(ret); // true
final var driver = DriverManager.getDriver("jdbc:derby:");
final var ret = driver.acceptsURL("abc");
System.out.println(ret); // false
Connection connect (String url, Properties info)
指定されたURLにデータベース接続を試みます。
record Product(String name, int stock) {
}
final var products = List.of(
new Product("Orange", 10),
new Product("Banana", 20),
new Product("Apple", 30)
);
final var protocol = "jdbc:derby:";
final var driver = DriverManager.getDriver(protocol);
final var url = protocol + "memory:db";
final var properties = new Properties();
properties.setProperty("create", "true");
try (final var connection = driver.connect(url, properties)) {
System.out.println("-- create table --");
try (final var statement = connection.createStatement()) {
final var ret = statement.executeUpdate("""
CREATE TABLE products (
name VARCHAR(20),
stock INTEGER
)
""");
System.out.println("ret = " + ret);
}
System.out.println("-- insert --");
try (final var statement = connection.prepareStatement("""
INSERT INTO products VALUES( ?, ? )
""")) {
for (final var product : products) {
statement.setString(1, product.name());
statement.setInt(2, product.stock());
final var ret = statement.executeUpdate();
System.out.println("ret = " + ret);
}
}
System.out.println("-- select --");
try (final var statement = connection.createStatement()) {
final var result = statement.executeQuery("""
SELECT * FROM products
""");
while (result.next()) {
final var name = result.getString("name");
final var stock = result.getInt("stock");
System.out.println(name + " : " + stock);
}
}
// 結果
// ↓
//-- create table --
//ret = 0
//-- insert --
//ret = 1
//ret = 1
//ret = 1
//-- select --
//Orange : 10
//Banana : 20
//Apple : 30
}
int getMajorVersion ()
ドライバのメジャー・バージョン番号を取得します。
final var driver = DriverManager.getDriver("jdbc:derby:");
System.out.println(driver.getMajorVersion()); // 10
System.out.println(driver.getMinorVersion()); // 17
int getMinorVersion ()
ドライバのマイナー・バージョンを取得します。
final var driver = DriverManager.getDriver("jdbc:derby:");
System.out.println(driver.getMajorVersion()); // 10
System.out.println(driver.getMinorVersion()); // 17
Logger getParentLogger ()
このドライバで使用されるすべてのロガーの親ロガーを返します。
// Apache Derby はロガーをサポートしていないようです。
try {
final var driver = DriverManager.getDriver("jdbc:derby:");
final var logger = driver.getParentLogger();
} catch (SQLFeatureNotSupportedException e) {
System.out.println("SQLFeatureNotSupportedException! : " + e.getMessage());
}
// 結果
// ↓
//SQLFeatureNotSupportedException! : Feature not implemented: getParentLogger().
DriverPropertyInfo[] getPropertyInfo (String url, Properties info)
このドライバの有効なプロパティについての情報を取得します。
final var protocol = "jdbc:derby:";
final var driver = DriverManager.getDriver(protocol);
final var values = driver.getPropertyInfo(protocol, new Properties());
for (final var value : values) {
System.out.println(value.name + " : " + value.description);
}
// 結果
// ↓
//databaseName : Database identity
//encryptionProvider : Cryptographic service provider
//encryptionAlgorithm : Cryptographic algorithm
//encryptionKeyLength : Cryptographic key length
//encryptionKey : External cryptographic key
//territory : Locale for the database
//collation : Collation for character datatypes
//user : User name
//logDevice : Log directory path
//rollForwardRecoveryFrom : Backup path for roll-forward recovery
//createFrom : Backup path for creating database from backup
//restoreFrom : Backup path for restoring database from backup
//bootPassword : Secret cryptographic key
//password : User password
//shutdown : Shut down Derby
//deregister : Deregister AutoloadedDriver
//create : Create database
//dataEncryption : Encrypt database on disk
//upgrade : Upgrade database
final var protocol = "jdbc:derby:";
final var driver = DriverManager.getDriver(protocol);
final var info = new Properties();
info.setProperty("shutdown", "true");
final var values = driver.getPropertyInfo(protocol, info);
System.out.println(values.length); // 0
boolean jdbcCompliant ()
このドライバが正規のJDBC準拠ドライバかどうかを報告します。
final var driver = DriverManager.getDriver("jdbc:derby:");
final var ret = driver.jdbcCompliant();
System.out.println(ret); // true
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