Java HikariCP包装器(线程安全)
我正在学习使用HikariCP(我是java新手),我发现了一个包装器,但我认为它不是线程安全的,单例的实例是线程安全的,而不是getConnection()方法。课程内容如下:Java HikariCP包装器(线程安全),java,thread-safety,singleton,wrapper,hikaricp,Java,Thread Safety,Singleton,Wrapper,Hikaricp,我正在学习使用HikariCP(我是java新手),我发现了一个包装器,但我认为它不是线程安全的,单例的实例是线程安全的,而不是getConnection()方法。课程内容如下: public class HikariCPWrapper{ private static final HikariCPWrapper INSTANCE; private HikariDataSource ds; static { INSTANCE = new Hikari
public class HikariCPWrapper{
private static final HikariCPWrapper INSTANCE;
private HikariDataSource ds;
static
{
INSTANCE = new HikariCPWrapper();
}
private HikariCPWrapper(){
HikariConfig config = new HikariConfig();
//config.set...
//...
ds = new HikariDataSource(config);
}
public static HikariCPWrapper getInstance ()
{
return INSTANCE;
}
public Connection getConnection() throws SQLException
{
return ds.getConnection();
}
}
我需要将参数发送到HikariConfig或HikariDataSource,所以我用这种方式重新编写:
public interface IConnectionProvider {
void init(String jdbcUrl, String user, String password);
Connection getConnection() throws SQLException;
}
public class ConnectionProviderHikariCP implements IConnectionProvider{
private static final ConnectionProviderHikariCP INSTANCE;
private final HikariDataSource hikariDataSource;
private Boolean initialized;
//class initializer:
static
{
INSTANCE = new ConnectionProviderHikariCP();
}
private ConnectionProviderHikariCP() {
hikariDataSource = new HikariDataSource();
initialized = false;
}
public static ConnectionProviderHikariCP getInstance() {
return INSTANCE;
}
@Override
public synchronized void init(String jdbcUrl, String user, String password) {
hikariDataSource.setJdbcUrl(jdbcUrl);
hikariDataSource.setUsername(user);
hikariDataSource.setPassword(password);
initialized = true;
}
@Override
public synchronized Connection getConnection() throws SQLException {
if(!initialized)
throw new UnsupportedOperationException("Debe inicializar mediante el método Init() primero!!!!!.");
return hikariDataSource.getConnection();
}
}
IConnectionProvider connectionProvider = ConnectionProviderHikariCP.getInstance();
connectionProvider.init(url, user, passwd);
BaseDAOFactory fatory = new MySqlDAOFactory(connectionProvider);
IExerciseBO exerciseBO = new ExerciseBO(fatory);
我这样使用它:
public interface IConnectionProvider {
void init(String jdbcUrl, String user, String password);
Connection getConnection() throws SQLException;
}
public class ConnectionProviderHikariCP implements IConnectionProvider{
private static final ConnectionProviderHikariCP INSTANCE;
private final HikariDataSource hikariDataSource;
private Boolean initialized;
//class initializer:
static
{
INSTANCE = new ConnectionProviderHikariCP();
}
private ConnectionProviderHikariCP() {
hikariDataSource = new HikariDataSource();
initialized = false;
}
public static ConnectionProviderHikariCP getInstance() {
return INSTANCE;
}
@Override
public synchronized void init(String jdbcUrl, String user, String password) {
hikariDataSource.setJdbcUrl(jdbcUrl);
hikariDataSource.setUsername(user);
hikariDataSource.setPassword(password);
initialized = true;
}
@Override
public synchronized Connection getConnection() throws SQLException {
if(!initialized)
throw new UnsupportedOperationException("Debe inicializar mediante el método Init() primero!!!!!.");
return hikariDataSource.getConnection();
}
}
IConnectionProvider connectionProvider = ConnectionProviderHikariCP.getInstance();
connectionProvider.init(url, user, passwd);
BaseDAOFactory fatory = new MySqlDAOFactory(connectionProvider);
IExerciseBO exerciseBO = new ExerciseBO(fatory);
但是我对java没有经验,所以我需要你的建议。
一流(原始)螺纹安全吗?
我的实现是线程安全的吗?HikariCP本身是线程安全的。据我所知,您试图做的是在通过
init()
方法初始化HikariDataSource
之前阻止调用方调用getConnection()
。您可能还希望阻止对数据源的多次调用init()
就池吞吐量而言,用synchronized包装getConnection()
,通常是个坏主意。基于以上代码,我推荐以下模式:
public class ConnectionProviderHikariCP implements IConnectionProvider {
private static final ConnectionProviderHikariCP INSTANCE;
private final HikariDataSource hikariDataSource;
private AtomicBoolean initialized;
//class initializer:
static
{
INSTANCE = new ConnectionProviderHikariCP();
}
private ConnectionProviderHikariCP() {
hikariDataSource = new HikariDataSource();
initialized = new AtomicInteger();
}
public static ConnectionProviderHikariCP getInstance() {
return INSTANCE;
}
@Override
public void init(String jdbcUrl, String user, String password) {
if (initialized.compareAndSet(false, true)) {
hikariDataSource.setJdbcUrl(jdbcUrl);
hikariDataSource.setUsername(user);
hikariDataSource.setPassword(password);
}
else {
throw new IllegalStateException("Connection provider already initialized.");
}
}
@Override
public Connection getConnection() throws SQLException {
if (initialized.get()) {
return hikariDataSource.getConnection();
}
throw new UnsupportedOperationException("Debe inicializar mediante el método Init() primero!!!!!.");
}
}
HikariCP本身是线程安全的。据我所知,您试图做的是在通过init()
方法初始化HikariDataSource
之前阻止调用方调用getConnection()
。您可能还希望阻止对数据源的多次调用init()
就池吞吐量而言,用synchronized包装getConnection()
,通常是个坏主意。基于以上代码,我推荐以下模式:
public class ConnectionProviderHikariCP implements IConnectionProvider {
private static final ConnectionProviderHikariCP INSTANCE;
private final HikariDataSource hikariDataSource;
private AtomicBoolean initialized;
//class initializer:
static
{
INSTANCE = new ConnectionProviderHikariCP();
}
private ConnectionProviderHikariCP() {
hikariDataSource = new HikariDataSource();
initialized = new AtomicInteger();
}
public static ConnectionProviderHikariCP getInstance() {
return INSTANCE;
}
@Override
public void init(String jdbcUrl, String user, String password) {
if (initialized.compareAndSet(false, true)) {
hikariDataSource.setJdbcUrl(jdbcUrl);
hikariDataSource.setUsername(user);
hikariDataSource.setPassword(password);
}
else {
throw new IllegalStateException("Connection provider already initialized.");
}
}
@Override
public Connection getConnection() throws SQLException {
if (initialized.get()) {
return hikariDataSource.getConnection();
}
throw new UnsupportedOperationException("Debe inicializar mediante el método Init() primero!!!!!.");
}
}
一切都是线程安全的。不过,我会修改代码,使其遵守Java命名约定:mathods以小写字母开头,变量不包含下划线。getConnection()不应引发异常,但应引发SQLException。静态块中的try/catch是无用的,因为构造函数不会引发任何异常。@JBNizet谢谢。那么我可以跳过在init()和getConnection()方法中同步的put吗?(我会用你的建议更新代码)。删除它们会使代码不具有线程安全性。@JBNizet哦,我不明白你的第一条评论。谢谢,一切都是线程安全的。不过,我会修改代码,使其遵守Java命名约定:mathods以小写字母开头,变量不包含下划线。getConnection()不应引发异常,但应引发SQLException。静态块中的try/catch是无用的,因为构造函数不会引发任何异常。@JBNizet谢谢。那么我可以跳过在init()和getConnection()方法中同步的put吗?(我会用你的建议更新代码)。删除它们会使代码不具有线程安全性。@JBNizet哦,我不明白你的第一条评论。非常感谢。