/*
* Copyright 2002-2008 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.jdbc.datasource;
import java.sql.Connection;
import java.sql.SQLException;
import org.springframework.core.NamedThreadLocal;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
/**
* An adapter for a target JDBC {@link javax.sql.DataSource}, applying the specified
* user credentials to every standard <code>getConnection()</code> call, implicitly
* invoking <code>getConnection(username, password)</code> on the target.
* All other methods simply delegate to the corresponding methods of the
* target DataSource.
*
* <p>Can be used to proxy a target JNDI DataSource that does not have user
* credentials configured. Client code can work with this DataSource as usual,
* using the standard <code>getConnection()</code> call.
*
* <p>In the following example, client code can simply transparently work with
* the preconfigured "myDataSource", implicitly accessing "myTargetDataSource"
* with the specified user credentials.
*
* <pre class="code">
* <bean id="myTargetDataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
* <property name="jndiName" value="java:comp/env/jdbc/myds"/>
* </bean>
*
* <bean id="myDataSource" class="org.springframework.jdbc.datasource.UserCredentialsDataSourceAdapter">
* <property name="targetDataSource" ref="myTargetDataSource"/>
* <property name="username" value="myusername"/>
* <property name="password" value="mypassword"/>
* </bean></pre>
*
* <p>If the "username" is empty, this proxy will simply delegate to the
* standard <code>getConnection()</code> method of the target DataSource.
* This can be used to keep a UserCredentialsDataSourceAdapter bean definition
* just for the <i>option</i> of implicitly passing in user credentials if
* the particular target DataSource requires it.
*
* @author Juergen Hoeller
* @since 1.0.2
* @see #getConnection
*/
public class UserCredentialsDataSourceAdapter extends DelegatingDataSource {
private String username;
private String password;
private final ThreadLocal threadBoundCredentials = new NamedThreadLocal("Current JDBC user credentials");
/**
* Set the default username that this adapter should use for retrieving Connections.
* <p>Default is no specific user. Note that an explicitly specified username
* will always override any username/password specified at the DataSource level.
* @see #setPassword
* @see #setCredentialsForCurrentThread(String, String)
* @see #getConnection(String, String)
*/
public void setUsername(String username) {
this.username = username;
}
/**
* Set the default user's password that this adapter should use for retrieving Connections.
* <p>Default is no specific password. Note that an explicitly specified username
* will always override any username/password specified at the DataSource level.
* @see #setUsername
* @see #setCredentialsForCurrentThread(String, String)
* @see #getConnection(String, String)
*/
public void setPassword(String password) {
this.password = password;
}
/**
* Set user credententials for this proxy and the current thread.
* The given username and password will be applied to all subsequent
* <code>getConnection()</code> calls on this DataSource proxy.
* <p>This will override any statically specified user credentials,
* that is, values of the "username" and "password" bean properties.
* @param username the username to apply
* @param password the password to apply
* @see #removeCredentialsFromCurrentThread
*/
public void setCredentialsForCurrentThread(String username, String password) {
this.threadBoundCredentials.set(new JdbcUserCredentials(username, password));
}
/**
* Remove any user credentials for this proxy from the current thread.
* Statically specified user credentials apply again afterwards.
* @see #setCredentialsForCurrentThread
*/
public void removeCredentialsFromCurrentThread() {
this.threadBoundCredentials.set(null);
}
/**
* Determine whether there are currently thread-bound credentials,
* using them if available, falling back to the statically specified
* username and password (i.e. values of the bean properties) else.
* <p>Delegates to {@link #doGetConnection(String, String)} with the
* determined credentials as parameters.
*/
public Connection getConnection() throws SQLException {
JdbcUserCredentials threadCredentials = (JdbcUserCredentials) this.threadBoundCredentials.get();
if (threadCredentials != null) {
return doGetConnection(threadCredentials.username, threadCredentials.password);
}
else {
return doGetConnection(this.username, this.password);
}
}
/**
* Simply delegates to {@link #doGetConnection(String, String)},
* keeping the given user credentials as-is.
*/
public Connection getConnection(String username, String password) throws SQLException {
return doGetConnection(username, password);
}
/**
* This implementation delegates to the <code>getConnection(username, password)</code>
* method of the target DataSource, passing in the specified user credentials.
* If the specified username is empty, it will simply delegate to the standard
* <code>getConnection()</code> method of the target DataSource.
* @param username the username to use
* @param password the password to use
* @return the Connection
* @see javax.sql.DataSource#getConnection(String, String)
* @see javax.sql.DataSource#getConnection()
*/
protected Connection doGetConnection(String username, String password) throws SQLException {
Assert.state(getTargetDataSource() != null, "'targetDataSource' is required");
if (StringUtils.hasLength(username)) {
return getTargetDataSource().getConnection(username, password);
}
else {
return getTargetDataSource().getConnection();
}
}
/**
* Inner class used as ThreadLocal value.
*/
private static class JdbcUserCredentials {
public final String username;
public final String password;
private JdbcUserCredentials(String username, String password) {
this.username = username;
this.password = password;
}
public String toString() {
return "JdbcUserCredentials[username='" + this.username + "',password='" + this.password + "']";
}
}
}