Can I use spring boot datasource to get connection object so as to use it with conn.executeQuery() manually? - spring

I am working on spring boot application with Mysql backend and trying to use springboots datasource Bean to get connection object so as to use it with the following stmts:
stmt =conn.createStatement()
stmt.executeQuery("show tables");
which is expected to return the table list. Below is the code of connection class:
public class Test {
#Autowired
DataSource datasource;
public void test1(){
System.out.println("Inside Test Method");
try {
Connection conn = datasource.getConnection();
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("show tables");
while (rs.next()) {
System.out.println(rs.getString("TableNames"));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch(NullPointerException e){
System.out.println("Null Pointer exception");
}
}
}
But the datasource object is throwing null value and hence it doesnt return any connection object.
Following is the application.yml
spring:
datasource:
url: jdbc:mysql://localhost:3306/test
driver-class-name: com.mysql.jdbc.Driver
username: ****
password: ****
initial-size: 1
max-idle: 2
max-active: 3
Ideally the datasource object should read these properties and be able to return connection object. Not sure if my understanding is correct.
Can anyone help me out in figuring the issue pls ?

I think spring boot automated this process completely. One doesn't have to inject the data source manually & connection pool mechanism is also automated. Just adding the connection properties and pool properties in yaml file or properties file under src/main/resources. It will inject the data source for you.

Related

java.lang.ClassNotFoundException: jdbc:mysql Exception [duplicate]

How do you connect to a MySQL database in Java?
When I try, I get
java.sql.SQLException: No suitable driver found for jdbc:mysql://database/table
at java.sql.DriverManager.getConnection(DriverManager.java:689)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
Or
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
Or
java.lang.ClassNotFoundException: com.mysql.cj.jdbc.Driver
Here's a step by step explanation how to install MySQL and JDBC and how to use it:
Download and install the MySQL server. Just do it the usual way. Remember the port number whenever you've changed it. It's by default 3306.
Download the JDBC driver and put in classpath, extract the ZIP file and put the containing JAR file in the classpath. The vendor-specific JDBC driver is a concrete implementation of the JDBC API (tutorial here).
If you're using an IDE like Eclipse or Netbeans, then you can add it to the classpath by adding the JAR file as Library to the Build Path in project's properties.
If you're doing it "plain vanilla" in the command console, then you need to specify the path to the JAR file in the -cp or -classpath argument when executing your Java application.
java -cp .;/path/to/mysql-connector.jar com.example.YourClass
The . is just there to add the current directory to the classpath as well so that it can locate com.example.YourClass and the ; is the classpath separator as it is in Windows. In Unix and clones : should be used.
Create a database in MySQL. Let's create a database javabase. You of course want World Domination, so let's use UTF-8 as well.
CREATE DATABASE javabase DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci;
Create a user for Java and grant it access. Simply because using root is a bad practice.
CREATE USER 'java'#'localhost' IDENTIFIED BY 'password';
GRANT ALL ON javabase.* TO 'java'#'localhost' IDENTIFIED BY 'password';
Yes, java is the username and password is the password here.
Determine the JDBC URL. To connect the MySQL database using Java you need an JDBC URL in the following syntax:
jdbc:mysql://hostname:port/databasename
hostname: The hostname where MySQL server is installed. If it's installed at the same machine where you run the Java code, then you can just use localhost. It can also be an IP address like 127.0.0.1. If you encounter connectivity problems and using 127.0.0.1 instead of localhost solved it, then you've a problem in your network/DNS/hosts config.
port: The TCP/IP port where MySQL server listens on. This is by default 3306.
databasename: The name of the database you'd like to connect to. That's javabase.
So the final URL should look like:
jdbc:mysql://localhost:3306/javabase
Test the connection to MySQL using Java. Create a simple Java class with a main() method to test the connection.
String url = "jdbc:mysql://localhost:3306/javabase";
String username = "java";
String password = "password";
System.out.println("Connecting database...");
try (Connection connection = DriverManager.getConnection(url, username, password)) {
System.out.println("Database connected!");
} catch (SQLException e) {
throw new IllegalStateException("Cannot connect the database!", e);
}
If you get a SQLException: No suitable driver, then it means that either the JDBC driver wasn't autoloaded at all or that the JDBC URL is wrong (i.e. it wasn't recognized by any of the loaded drivers). Normally, a JDBC 4.0 driver should be autoloaded when you just drop it in runtime classpath. To exclude one and other, you can always manually load it as below:
System.out.println("Loading driver...");
try {
Class.forName("com.mysql.jdbc.Driver");
System.out.println("Driver loaded!");
} catch (ClassNotFoundException e) {
throw new IllegalStateException("Cannot find the driver in the classpath!", e);
}
Note that the newInstance() call is not needed here. It's just to fix the old and buggy org.gjt.mm.mysql.Driver. Explanation here. If this line throws ClassNotFoundException, then the JAR file containing the JDBC driver class is simply not been placed in the classpath.
Note that you don't need to load the driver everytime before connecting. Just only once during application startup is enough.
If you get a SQLException: Connection refused or Connection timed out or a MySQL specific CommunicationsException: Communications link failure, then it means that the DB isn't reachable at all. This can have one or more of the following causes:
IP address or hostname in JDBC URL is wrong.
Hostname in JDBC URL is not recognized by local DNS server.
Port number is missing or wrong in JDBC URL.
DB server is down.
DB server doesn't accept TCP/IP connections.
DB server has run out of connections.
Something in between Java and DB is blocking connections, e.g. a firewall or proxy.
To solve the one or the other, follow the following advices:
Verify and test them with ping.
Refresh DNS or use IP address in JDBC URL instead.
Verify it based on my.cnf of MySQL DB.
Start the DB.
Verify if mysqld is started without the --skip-networking option.
Restart the DB and fix your code accordingly that it closes connections in finally.
Disable firewall and/or configure firewall/proxy to allow/forward the port.
Note that closing the Connection is extremely important. If you don't close connections and keep getting a lot of them in a short time, then the database may run out of connections and your application may break. Always acquire the Connection in a try-with-resources statement. Or if you're not on Java 7 yet, explicitly close it in finally of a try-finally block. Closing in finally is just to ensure that it get closed as well in case of an exception. This also applies to Statement, PreparedStatement and ResultSet.
That was it as far the connectivity concerns. You can find here a more advanced tutorial how to load and store fullworthy Java model objects in a database with help of a basic DAO class.
Using a Singleton Pattern for the DB connection is a bad approach. See among other questions: Is it safe to use a static java.sql.Connection instance in a multithreaded system?. This is a #1 starters mistake.
DriverManager is a fairly old way of doing things. The better way is to get a DataSource, either by looking one up that your app server container already configured for you:
Context context = new InitialContext();
DataSource dataSource = (DataSource) context.lookup("java:comp/env/jdbc/myDB");
or instantiating and configuring one from your database driver directly:
MysqlDataSource dataSource = new MysqlDataSource();
dataSource.setUser("scott");
dataSource.setPassword("tiger");
dataSource.setServerName("myDBHost.example.org");
and then obtain connections from it, same as above:
Connection conn = dataSource.getConnection();
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT ID FROM USERS");
...
rs.close();
stmt.close();
conn.close();
Initialize database constants
Create constant properties database username, password, URL and drivers, polling limit etc.
// init database constants
// com.mysql.jdbc.Driver
private static final String DATABASE_DRIVER = "com.mysql.cj.jdbc.Driver";
private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/database_name";
private static final String USERNAME = "root";
private static final String PASSWORD = "";
private static final String MAX_POOL = "250"; // set your own limit
Initialize Connection and Properties
Once the connection is established, it is better to store for reuse purpose.
// init connection object
private Connection connection;
// init properties object
private Properties properties;
Create Properties
The properties object hold the connection information, check if it is already set.
// create properties
private Properties getProperties() {
if (properties == null) {
properties = new Properties();
properties.setProperty("user", USERNAME);
properties.setProperty("password", PASSWORD);
properties.setProperty("MaxPooledStatements", MAX_POOL);
}
return properties;
}
Connect the Database
Now connect to database using the constants and properties initialized.
// connect database
public Connection connect() {
if (connection == null) {
try {
Class.forName(DATABASE_DRIVER);
connection = DriverManager.getConnection(DATABASE_URL, getProperties());
} catch (ClassNotFoundException | SQLException e) {
// Java 7+
e.printStackTrace();
}
}
return connection;
}
Disconnect the database
Once you are done with database operations, just close the connection.
// disconnect database
public void disconnect() {
if (connection != null) {
try {
connection.close();
connection = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
}
Everything together
Use this class MysqlConnect directly after changing database_name, username and password etc.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
public class MysqlConnect {
// init database constants
private static final String DATABASE_DRIVER = "com.mysql.cj.jdbc.Driver";
private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/database_name";
private static final String USERNAME = "root";
private static final String PASSWORD = "";
private static final String MAX_POOL = "250";
// init connection object
private Connection connection;
// init properties object
private Properties properties;
// create properties
private Properties getProperties() {
if (properties == null) {
properties = new Properties();
properties.setProperty("user", USERNAME);
properties.setProperty("password", PASSWORD);
properties.setProperty("MaxPooledStatements", MAX_POOL);
}
return properties;
}
// connect database
public Connection connect() {
if (connection == null) {
try {
Class.forName(DATABASE_DRIVER);
connection = DriverManager.getConnection(DATABASE_URL, getProperties());
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
}
return connection;
}
// disconnect database
public void disconnect() {
if (connection != null) {
try {
connection.close();
connection = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
How to Use?
Initialize the database class.
// !_ note _! this is just init
// it will not create a connection
MysqlConnect mysqlConnect = new MysqlConnect();
Somewhere else in your code ...
String sql = "SELECT * FROM `stackoverflow`";
try {
PreparedStatement statement = mysqlConnect.connect().prepareStatement(sql);
... go on ...
... go on ...
... DONE ....
} catch (SQLException e) {
e.printStackTrace();
} finally {
mysqlConnect.disconnect();
}
This is all :) If anything to improve edit it! Hope this is helpful.
String url = "jdbc:mysql://127.0.0.1:3306/yourdatabase";
String user = "username";
String password = "password";
// Load the Connector/J driver
Class.forName("com.mysql.jdbc.Driver").newInstance();
// Establish connection to MySQL
Connection conn = DriverManager.getConnection(url, user, password);
Here's the very minimum you need to get data out of a MySQL database:
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection conn = DriverManager.getConnection
("jdbc:mysql://localhost:3306/foo", "root", "password");
Statement stmt = conn.createStatement();
stmt.execute("SELECT * FROM `FOO.BAR`");
stmt.close();
conn.close();
Add exception handling, configuration etc. to taste.
you need to have mysql connector jar in your classpath.
in Java JDBC API makes everything with databases. using JDBC we can write Java applications to
1. Send queries or update SQL to DB(any relational Database)
2. Retrieve and process the results from DB
with below three steps we can able to retrieve data from any Database
Connection con = DriverManager.getConnection(
"jdbc:myDriver:DatabaseName",
dBuserName,
dBuserPassword);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT a, b, c FROM Table");
while (rs.next()) {
int x = rs.getInt("a");
String s = rs.getString("b");
float f = rs.getFloat("c");
}
You can see all steps to connect MySQL database from Java application here. For other database, you just need to change the driver in first step only. Please make sure that you provide right path to database and correct username and password.
Visit http://apekshit.com/t/51/Steps-to-connect-Database-using-JAVA
MySQL JDBC Connection with useSSL.
private String db_server = BaseMethods.getSystemData("db_server");
private String db_user = BaseMethods.getSystemData("db_user");
private String db_password = BaseMethods.getSystemData("db_password");
private String connectToDb() throws Exception {
String jdbcDriver = "com.mysql.jdbc.Driver";
String dbUrl = "jdbc:mysql://" + db_server +
"?verifyServerCertificate=false" +
"&useSSL=true" +
"&requireSSL=true";
System.setProperty(jdbcDriver, "");
Class.forName(jdbcDriver).newInstance();
Connection conn = DriverManager.getConnection(dbUrl, db_user, db_password);
Statement statement = conn.createStatement();
String query = "SELECT EXTERNAL_ID FROM offer_letter where ID =" + "\"" + letterID + "\"";
ResultSet resultSet = statement.executeQuery(query);
resultSet.next();
return resultSet.getString(1);
}
Short and Sweet code.
try {
Class.forName("com.mysql.jdbc.Driver");
System.out.println("Driver Loaded");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/testDB","root","");
//Database Name - testDB, Username - "root", Password - ""
System.out.println("Connected...");
} catch(Exception e) {
e.printStackTrace();
}
For SQL server 2012
try {
String url = "jdbc:sqlserver://KHILAN:1433;databaseName=testDB;user=Khilan;password=Tuxedo123";
//KHILAN is Host and 1433 is port number
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
System.out.println("Driver Loaded");
conn = DriverManager.getConnection(url);
System.out.println("Connected...");
} catch(Exception e) {
e.printStackTrace();
}
Connection I was using some time ago, it was looking like the easiest way, but also there were recommendation to make there if statement- exactly
Connection con = DriverManager.getConnection(
"jdbc:myDriver:DatabaseName",
dBuserName,
dBuserPassword);
if (con != null){
//..handle your code there
}
Or something like in that way :)
Probably there's some case, while getConnection can return null :)
HOW
To set up the Driver to run a quick sample
1. Go to https://dev.mysql.com/downloads/connector/j/, get the latest version of Connector/J
2. Remember to set the classpath to include the path of the connector jar file.
If we don't set it correctly, below errors can occur:
No suitable driver found for jdbc:mysql://127.0.0.1:3306/msystem_development
java.lang.ClassNotFoundException: com.mysql.jdbc:Driver
To set up the CLASSPATH
Method 1: set the CLASSPATH variable.
export CLASSPATH=".:mysql-connector-java-VERSION.jar"
java MyClassFile
In the above command, I have set the CLASSPATH to the current folder and mysql-connector-java-VERSION.jar file. So when the java MyClassFile command executed, java application launcher will try to load all the Java class in CLASSPATH.
And it found the Drive class => BOOM errors was gone.
Method 2:
java -cp .:mysql-connector-java-VERSION.jar MyClassFile
Note: Class.forName("com.mysql.jdbc.Driver"); This is deprecated at this moment 2019 Apr.
Hope this can help someone!
MySql JDBC Connection:
Class.forName("com.mysql.jdbc.Driver");
Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/DatabaseName","Username","Password");
Statement stmt=con.createStatement();
stmt = con.createStatement();
ResultSet rs=stmt.executeQuery("Select * from Table");
Short Code
public class DB {
public static Connection c;
public static Connection getConnection() throws Exception {
if (c == null) {
Class.forName("com.mysql.jdbc.Driver");
c =DriverManager.getConnection("jdbc:mysql://localhost:3306/DATABASE", "USERNAME", "Password");
}
return c;
}
// Send data TO Database
public static void setData(String sql) throws Exception {
DB.getConnection().createStatement().executeUpdate(sql);
}
// Get Data From Database
public static ResultSet getData(String sql) throws Exception {
ResultSet rs = DB.getConnection().createStatement().executeQuery(sql);
return rs;
}
}
Download JDBC Driver
Download link (Select platform independent): https://dev.mysql.com/downloads/connector/j/
Move JDBC Driver to C Drive
Unzip the files and move to C:\ drive. Your driver path should be like C:\mysql-connector-java-8.0.19\mysql-connector-java-8.0.19
Run Your Java
java -cp "C:\mysql-connector-java-8.0.19\mysql-connector-java-8.0.19\mysql-connector-java-8.0.19.jar" testMySQL.java
testMySQL.java
import java.sql.*;
import java.io.*;
public class testMySQL {
public static void main(String[] args) {
// TODO Auto-generated method stub
try
{
Class.forName("com.mysql.cj.jdbc.Driver");
Connection con=DriverManager.getConnection(
"jdbc:mysql://localhost:3306/db?useSSL=false&useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC","root","");
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("show databases;");
System.out.println("Connected");
}
catch(Exception e)
{
System.out.println(e);
}
}
}

Spring data jpa and JdbcTemplate - Should I close connection?

Should I close connection or Spring will handle it?
#Autowired
MyRepository myRepository;
#Autowired
#Qualifier("myJdbc")
JdbcTemplate myJdbc;
#GetMapping("/v1/controlla-abilitazione")
public Set<String> controlloAbilitazione() {
try {
Connection conn = myJdbc.getDataSource().getConnection();
//Here I use previous connection to call an oracle PL/SQL via basic oracle jdbc
//Should I close connection?
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
(I know that I can use Spring to handle PL/SQL, but Spring doesn't have native support for Oracle Type as return from PL/SQL)
Not tried but if you execute the SQL or PL/SQL query from the Connection object, you don't use Spring JDBC features for executing your query, so you should not expect that Spring closes the connection for you. It is not aware of the datasource provider activity about that.
So Connection.close() should be probably required.
It is an theory but you could check it easily enough. Store the Connection in a field of the bean and do a check at the beginning of the method.
Connection conn;
#GetMapping("/v1/controlla-abilitazione")
public Set<String> controlloAbilitazione() {
if (conn != null && !conn.isClosed){
throw new RuntimeException("Oh it was not closed");
}
try {
conn = myJdbc.getDataSource().getConnection();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
Now invoke your controller once and another time. If you get the exception, you know why.

Facing Too many connection issue on HIkariCP

I have a Java JDBC application, after 100 queries of Select Jetty server crashed and return below error:
ERROR com.zaxxer.hikari.pool.HikariPool - dev-server - Exception during pool initialization.
java.sql.SQLNonTransientConnectionException: Too many connections
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:526)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:513)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:115)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:1606)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:633)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:347)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:219)
at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:95)
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:358)
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:201)
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:443)
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:514)
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:111)
at com.zaxxer.hikari.HikariDataSource.<init>(HikariDataSource.java:72)
at com.jrg.platform.commons.hikari.HikariDataSourceSupport.getDataSource(HikariDataSourceSupport.java:70)
at com.jrg.platform.commons.hikari.HikariDataSourceSupport.getConnection(HikariDataSourceSupport.java:82)
at com.jrg.platform.services.internal.pcms.data.campaign.CampaignAlertDaoImpl.getCampaignAlerts(CampaignAlertDaoImpl.java:40)
at com.jrg.platform.services.internal.pcms.service.CampaignAlertServiceImpl.campaignAlerts(CampaignAlertServiceImpl.java:43)
at com.jrg.platform.services.internal.pcms.resource.CampaignAlertResource.getCampaignAlerts(CampaignAlertResource.java:52)
at com.jrg.platform.services.internal.pcms.resource.CampaignAlertResource_$$_jvstf5a_6._d5getCampaignAlerts(CampaignAlertResource_$$_jvstf5a_6.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Unable to find the solution. I am just getting the connection from HikariDataSourceSupport and performing the query.
the sample code of getting connection is given below:
default HikariDataSource getDataSource(E e, boolean readOnly) throws IOException {
String key = this.getKey(e, readOnly);
Map<String, HikariDataSource> sources = this.getDataSources();
if(!sources.containsKey(key)) {
synchronized(this.getMonitor()) {
if(!sources.containsKey(key)) {
if(logger.isDebugEnabled()) {
logger.debug("creating new DataSource for {}", key);
}
Config config = this.getConfig(e, readOnly);
if(!config.hasPathOrNull("jdbcUrl")) {
throw new EnvironmentNotConfigured(e, readOnly);
}
sources.put(key, new HikariDataSource(new HikariConfig(ConfigUtils.asProperties(config))));
}
}
}
return (HikariDataSource)sources.get(key);
}
default Connection getConnection(E env, boolean readOnly) throws SQLException, IOException {
return this.getDataSource(env, readOnly).getConnection();
}
There was problem in configuration HikariCP. When request generated and try to get connection, the create connection method was creating the new datasource because the last state was destroy due to view scope of the bean.
now i have converted that class into to singalton and created the implementation of that interface to inject in the code. it is saving the state of previous data source connection. Now it is working perfect with minimum idle connections.
the code can be seen here:
APP.java
bind(HikariLucktasticDataSourceSupportImpl.class)
.to(HikariDataSourceSupport.class)
.named("hdsSupport")
.in(Singleton.class);
in DAO Layer:
#Inject
#Named("hdsSupport")
private HikariDataSourceSupport hdsSupport;

Mixing JdbcTemplate and raw JDBC

I am experiencing some strange behaviour which I can't easily explain. The following code runs fine:
try (Connection connection = dataSource.getConnection();
Statement statement = connection.createStatement()) {
statement.executeUpdate("DELETE FROM product");
} catch (Exception ex) {
throw new RuntimeException(ex);
}
try (Connection connection = dataSource.getConnection();
Statement statement = connection.createStatement()) {
statement.executeUpdate("INSERT INTO product ...");
} catch (SQLException ex) {
throw new RuntimeException(ex);
}
However this code causes a deadlock:
jdbcTemplate.update("DELETE FROM product");
try (Connection connection = dataSource.getConnection();
Statement statement = connection.createStatement()) {
statement.executeUpdate("INSERT INTO product ...");
} catch (SQLException ex) {
throw new RuntimeException(ex);
}
The exception is
java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction
Both jdbcTemplate and dataSource are created by Spring boot and autowired
#Autowired
private DataSource dataSource;
#Autowired
private JdbcTemplate jdbcTemplate;
The statements form part of a method in a service (with the #Transactional annotation)
Can anyone explain why this happens?
If you want to use your own JDBC code that plays nice with the connections managed by Spring's transaction management you should use DataSourceUtils to obtain the connection -- see http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/jdbc/datasource/DataSourceUtils.html#getConnection-javax.sql.DataSource-
In your example, depending on the transaction configuration, the first statement using the JdbcTemplate might not be committed yet, so it would block the next JDBC statement from a different connection. Using the DataSourceUtils, both statements would be using the same connection.

How to set autocommit to false in spring jdbc template

Currently I'm setting autocommit to false in spring through adding a property to a datasource bean id like below :
<property name="defaultAutoCommit" value="false" />
But i need to add it specifically in a single java method before executing my procedure.
I used the below code snippet.
getJdbcTemplate().getDataSource().getConnection().setAutoCommit(false);
But the above line was not setting autocommit to false?
Am i missing anything ?
or any alternative to set autocommit in a specific java method by spring
Thanks
The problem is that you are setting autocommit on a Connection, but JdbcTemplate doesn't remember that Connection; instead, it gets a new Connection for each operation, and that might or might not be the same Connection instance, depending on your DataSource implementation. Since defaultAutoCommit is not a property on DataSource, you have two options:
Assuming your concrete datasource has a setter for defaultAutoCommit (for example, org.apache.commons.dbcp.BasicDataSource), cast the DataSource to your concrete implementation. Of course this means that you can no longer change your DataSource in your Spring configuration, which defeats the purpose of dependency injection.
((BasicDataSource)getJdbcTemplate().getDataSource()).setDefaultAutoCommit(false);
Set the DataSource to a wrapper implementation that sets AutoCommit to false each time you fetch a connection.
final DataSource ds = getJdbcTemplate().getDataSource();
getJdbcTemplate().setDataSource(new DataSource(){
// You'll need to implement all the methods, simply delegating to ds
#Override
public Connection getConnection() throws SQLException {
Connection c = ds.getConnection();
c.setAutoCommit(false);
return c;
}
});
You need to get the current connection. e.g.
Connection conn = DataSourceUtils.getConnection(jdbcTemplate.getDataSource());
try {
conn.setAutoCommit(false);
/**
* Your Code
*/
conn.commit();
} catch (SQLException e) {
conn.rollback();
e.printStackTrace();
}
I'm posting this because I was looking for it everywhere: I used configuration property in Spring boot to achieve setting the default autocommit mode with:
spring.datasource.hikari.auto-commit: false
Spring Boot 2.4.x Doc for Hikari
You will have to do for each statement that the jdbcTemplate executes. Because for each jdbcTemplate.execute() etc it gets a new connection from the Datasource's connection pool. So you will have to set it for the connection that the connection the jdbcTemplate uses for that query. So you will have to do something like
jdbcTemplate.execute("<your sql query", new PreparedStatementCallback<Integer>(){
#Override
public Integer doInPreparedStatement(PreparedStatement stmt) throws SQLException, DataAccessException
{
Connection cxn = stmt.getConnection();
// set autocommit for that cxn object to false
cxn.setAutoCommit(false);
// set parameters etc in the stmt
....
....
cxn.commit();
// restore autocommit to true for that cxn object. because if the same object is obtained from the CxnPool later, autocommit will be false
cxn.setAutoCommit(true);
return 0;
}
});
Hope this helps
after 5 years still a valid question, i resolved my issue in this way :
set a connection with connection.setAutoCommit(false);
create a jbc template with that connection;
do your work and commit.
Connection connection = dataSource.getConnection();
connection.setAutoCommit(false);
JdbcTemplate jdbcTemplate =
new JdbcTemplate(newSingleConnectionDataSource(connection, true));
// ignore case in mapping result
jdbcTemplate.setResultsMapCaseInsensitive(true);
// do your stuff
connection.commit();
I just came across this and thought the solution would help someone even if it's too late.
As Yosef said, the connection that you get by calling getJdbcTemplate().getDataSource().getConnection() method may or may not be the one used for the communication with database for your operation.
Instead, if your requirement is to just test your script, not to commit the data, you can have a Apache Commons DBCP datasource with auto commit set to fault. The bean definition is given below:
/**
* A datasource with auto commit set to false.
*/
#Bean
public DataSource dbcpDataSource() throws Exception {
BasicDataSource ds = new BasicDataSource();
ds.setUrl(url);
ds.setUsername(username);
ds.setPassword(password);
ds.setDefaultAutoCommit(false);
ds.setEnableAutoCommitOnReturn(false);
return ds;
}
// Create either JdbcTemplate or NamedParameterJdbcTemplate as per your needs
#Bean
public NamedParameterJdbcTemplate dbcpNamedParameterJdbcTemplate() throws Exception {
return new NamedParameterJdbcTemplate(dbcpDataSource());
}
And use this datasource for any such operations.
If you wish to commit your transactions, I suggest you to have one more bean of the datasource with auto commit set to true which is the default behavior.
Hope it helps someone!
I needed it to do some unit testing
In fact Spring already provides the SingleConnectionDataSource implementation with the setAutoCommit method
// import org.springframework.jdbc.datasource.SingleConnectionDataSource;
SingleConnectionDataSource dataSource = new SingleConnectionDataSource();
dataSourceRX71.setAutoCommit(false);
dataSourceRX71.setDriverClassName("xxx");
dataSourceRX71.setUrl("xxx");
dataSourceRX71.setUsername("xxx");
dataSourceRX71.setPassword("xxx");
In some case you could just add #Transactional in the method, e.g. After some batch insert, execute commit at last.

Resources