To understand the concepts related to Spring JDBC framework with JDBC Template class, let us write a simple example which will implement Insert and Read operations on the following Student table.
CREATE TABLE Student( ID INT NOT NULL AUTO_INCREMENT, NAME VARCHAR(20) NOT NULL, AGE INT NOT NULL, PRIMARY KEY (ID) );
Let us proceed to write a simple console based Spring JDBC Application, which will demonstrate JDBC concepts.
Let's open the command console, go the C:\MVN directory and execute the following mvn command.
C:\MVN>mvn archetype:generate -DgroupId = com.howcodex -DartifactId = Student -DarchetypeArtifactId = maven-archetype-quickstart -DinteractiveMode = false
Maven will start processing and will create the complete Java application project structure.
[INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building Maven Stub Project (No POM) 1 [INFO] ------------------------------------------------------------------------ [INFO] [INFO] >>> maven-archetype-plugin:2.4:generate (default-cli) > generate-sources @ standalone-pom >>> [INFO] [INFO] <<< maven-archetype-plugin:2.4:generate (default-cli) < generate-sources @ standalone-pom <<< [INFO] [INFO] --- maven-archetype-plugin:2.4:generate (default-cli) @ standalone-pom -- - [INFO] Generating project in Batch mode Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/archetypes/ma ven-archetype-quickstart/1.0/maven-archetype-quickstart-1.0.jar Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/archetypes/mav en-archetype-quickstart/1.0/maven-archetype-quickstart-1.0.jar (5 KB at 1.1 KB/s ec) Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/archetypes/ma ven-archetype-quickstart/1.0/maven-archetype-quickstart-1.0.pom Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/archetypes/mav en-archetype-quickstart/1.0/maven-archetype-quickstart-1.0.pom (703 B at 1.2 KB/ sec) [INFO] ------------------------------------------------------------------------- --- [INFO] Using following parameters for creating project from Old (1.x) Archetype: maven-archetype-quickstart:1.0 [INFO] ------------------------------------------------------------------------- --- [INFO] Parameter: groupId, Value: com.howcodex [INFO] Parameter: packageName, Value: com.howcodex [INFO] Parameter: package, Value: com.howcodex [INFO] Parameter: artifactId, Value: Student [INFO] Parameter: basedir, Value: C:\MVN [INFO] Parameter: version, Value: 1.0-SNAPSHOT [INFO] project created from Old (1.x) Archetype in dir: C:\MVN\Student [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 01:17 min [INFO] Finished at: 2017-02-19T21:11:14+05:30 [INFO] Final Memory: 15M/114M [INFO] ------------------------------------------------------------------------
Now go to C:/MVN directory. You'll see a Java application project created named student (as specified in artifactId). Update the POM.xml to include Spring JDBC dependencies. Add Student.java, StudentMapper.java, MainApp.java, StudentDAO.java and StudentJDBCTemplate.java files.
<project xmlns = "http://maven.apache.org/POM/4.0.0" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation = "http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.howcodex</groupId> <artifactId>Student</artifactId> <packaging>jar</packaging> <version>1.0-SNAPSHOT</version> <name>Student</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>4.1.0.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.1.4.RELEASE</version> </dependency> </dependencies> </project>
Following is the content of the Data Access Object interface file StudentDAO.java.
package com.howcodex; import java.util.List; import javax.sql.DataSource; public interface StudentDAO { /** * This is the method to be used to initialize * database resources ie. connection. */ public void setDataSource(DataSource ds); /** * This is the method to be used to create * a record in the Student table. */ public void create(String name, Integer age); public Student getStudent(Integer id); /** * This is the method to be used to list down * all the records from the Student table. */ public List<Student> listStudents(); }
Following is the content of the Student.java file.
package com.howcodex; public class Student { private Integer age; private String name; private Integer id; public void setAge(Integer age) { this.age = age; } public Integer getAge() { return age; } public void setName(String name) { this.name = name; } public String getName() { return name; } public void setId(Integer id) { this.id = id; } public Integer getId() { return id; } }
Following is the content of the StudentMapper.java file.
package com.howcodex; import java.sql.ResultSet; import java.sql.SQLException; import org.springframework.jdbc.core.RowMapper; public class StudentMapper implements RowMapper<Student> { public Student mapRow(ResultSet rs, int rowNum) throws SQLException { Student student = new Student(); student.setId(rs.getInt("id")); student.setName(rs.getString("name")); student.setAge(rs.getInt("age")); return student; } }
Following is the implementation class file StudentJDBCTemplate.java for the defined DAO interface StudentDAO.
package com.howcodex; import java.util.List; import javax.sql.DataSource; import org.springframework.jdbc.core.JdbcTemplate; public class StudentJDBCTemplate implements StudentDAO { private DataSource dataSource; private JdbcTemplate jdbcTemplateObject; public void setDataSource(DataSource dataSource) { this.dataSource = dataSource; this.jdbcTemplateObject = new JdbcTemplate(dataSource); } public void create(String name, Integer age) { String SQL = "insert into Student (name, age) values (?, ?)"; jdbcTemplateObject.update( SQL, name, age); System.out.println("Created Record Name = " + name + " Age = " + age); return; } public List<Student> listStudents() { String SQL = "select * from Student"; List <Student> students = jdbcTemplateObject.query(SQL, new StudentMapper()); return students; } }
Following is the content of the MainApp.java file.
package com.howcodex; import java.util.List; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.howcodex.StudentJDBCTemplate; public class MainApp { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml"); StudentJDBCTemplate studentJDBCTemplate = (StudentJDBCTemplate) context.getBean("studentJDBCTemplate"); System.out.println("------Records Creation--------" ); studentJDBCTemplate.create("Zara", 11); studentJDBCTemplate.create("Nuha", 2); studentJDBCTemplate.create("Ayan", 15); System.out.println("------Listing Multiple Records--------" ); List<Student> students = studentJDBCTemplate.listStudents(); for (Student record : students) { System.out.print("ID : " + record.getId() ); System.out.print(", Name : " + record.getName() ); System.out.println(", Age : " + record.getAge()); } } }
Following is the configuration file Beans.xml.
<?xml version = "1.0" encoding = "UTF-8"?> <beans xmlns = "http://www.springframework.org/schema/beans" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation = "http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd "> <!-- Initialization for data source --> <bean id = "dataSource" class = "org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name = "driverClassName" value = "com.mysql.jdbc.Driver"/> <property name = "url" value = "jdbc:mysql://localhost:3306/TEST"/> <property name = "username" value = "root"/> <property name = "password" value = "admin"/> </bean> <!-- Definition for studentJDBCTemplate bean --> <bean id = "studentJDBCTemplate" class = "com.howcodex.StudentJDBCTemplate"> <property name = "dataSource" ref = "dataSource" /> </bean> </beans>
Once you are done creating the source and bean configuration files, let us run the application. If everything is fine with your application, it will print the following message.
------Records Creation-------- Created Record Name = Zara Age = 11 Created Record Name = Nuha Age = 2 Created Record Name = Ayan Age = 15 ------Listing Multiple Records-------- ID : 1, Name : Zara, Age : 11 ID : 2, Name : Nuha, Age : 2 ID : 3, Name : Ayan, Age : 15