JDBC removed...

This commit is contained in:
Amit Dixit 2016-04-04 12:24:15 +05:30
parent 28a5a43a47
commit deb15e2733
5 changed files with 433 additions and 541 deletions

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@ -1,105 +1,104 @@
/**
* The MIT License Copyright (c) 2014 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.util.Optional;
import java.util.UUID;
import org.apache.log4j.Logger;
/**
*
* The Data Mapper (DM) is a layer of software that separates the in-memory objects from the
* database. Its responsibility is to transfer data between the two and also to isolate them from
* each other. With Data Mapper the in-memory objects needn't know even that there's a database
* present; they need no SQL interface code, and certainly no knowledge of the database schema. (The
* database schema is always ignorant of the objects that use it.) Since it's a form of Mapper ,
* Data Mapper itself is even unknown to the domain layer.
* <p>
* The below example demonstrates basic CRUD operations: select, add, update, and delete.
*
*/
public final class App {
private static Logger log = Logger.getLogger(App.class);
private static final String DB_TYPE_ORACLE = "Oracle";
private static final String DB_TYPE_MYSQL = "MySQL";
/**
* Program entry point.
*
* @param args command line args.
*/
public static final void main(final String... args) {
if (log.isInfoEnabled() & args.length > 0) {
log.debug("App.main(), db type: " + args[0]);
}
StudentDataMapper mapper = null;
/* Check the desired db type from runtime arguments */
if (args.length == 0) {
/* Create default data mapper for mysql */
mapper = new StudentMySQLDataMapper();
} else if (args.length > 0 && DB_TYPE_ORACLE.equalsIgnoreCase(args[0])) {
/* Create new data mapper for mysql */
mapper = new StudentMySQLDataMapper();
} else if (args.length > 0 && DB_TYPE_MYSQL.equalsIgnoreCase(args[0])) {
/* Create new data mapper for oracle */
mapper = new StudentMySQLDataMapper();
} else {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Following data source(" + args[0] + ") is not supported");
}
/* Create new student */
Student student = new Student(UUID.randomUUID(), 1, "Adam", 'A');
/* Add student in respectibe db */
mapper.insert(student);
/* Find this student */
final Optional<Student> studentToBeFound = mapper.find(student.getGuId());
if (log.isDebugEnabled()) {
log.debug("App.main(), db find returned : " + studentToBeFound);
}
/* Update existing student object */
student = new Student(student.getGuId(), 1, "AdamUpdated", 'A');
/* Update student in respectibe db */
mapper.update(student);
/* Delete student in db */
mapper.delete(student);
}
private App() {}
}
/**
* The MIT License Copyright (c) 2014 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.util.Optional;
import org.apache.log4j.Logger;
/**
*
* The Data Mapper (DM) is a layer of software that separates the in-memory objects from the
* database. Its responsibility is to transfer data between the two and also to isolate them from
* each other. With Data Mapper the in-memory objects needn't know even that there's a database
* present; they need no SQL interface code, and certainly no knowledge of the database schema. (The
* database schema is always ignorant of the objects that use it.) Since it's a form of Mapper ,
* Data Mapper itself is even unknown to the domain layer.
* <p>
* The below example demonstrates basic CRUD operations: Create, Read, Update, and Delete.
*
*/
public final class App {
private static Logger log = Logger.getLogger(App.class);
private static final String DB_TYPE_ORACLE = "Oracle";
private static final String DB_TYPE_MYSQL = "MySQL";
/**
* Program entry point.
*
* @param args command line args.
*/
public static final void main(final String... args) {
if (log.isInfoEnabled() & args.length > 0) {
log.debug("App.main(), db type: " + args[0]);
}
StudentDataMapper mapper = null;
/* Check the desired db type from runtime arguments */
if (args.length == 0) {
/* Create default data mapper for mysql */
mapper = new StudentMySQLDataMapper();
} else if (args.length > 0 && DB_TYPE_ORACLE.equalsIgnoreCase(args[0])) {
/* Create new data mapper for mysql */
mapper = new StudentMySQLDataMapper();
} else if (args.length > 0 && DB_TYPE_MYSQL.equalsIgnoreCase(args[0])) {
/* Create new data mapper for oracle */
mapper = new StudentMySQLDataMapper();
} else {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Following data mapping type(" + args[0] + ") is not supported");
}
/* Create new student */
Student student = new Student(1, "Adam", 'A');
/* Add student in respectibe db */
mapper.insert(student);
/* Find this student */
final Optional<Student> studentToBeFound = mapper.find(student.getStudentId());
if (log.isDebugEnabled()) {
log.debug("App.main(), db find returned : " + studentToBeFound);
}
/* Update existing student object */
student = new Student(student.getStudentId(), "AdamUpdated", 'A');
/* Update student in respectibe db */
mapper.update(student);
/* Delete student in db */
mapper.delete(student);
}
private App() {}
}

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@ -1,83 +1,103 @@
/**
* The MIT License Copyright (c) 2016 Amit Dixit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.io.Serializable;
import java.util.UUID;
public final class Student implements Serializable {
private static final long serialVersionUID = 1L;
private UUID guid;
private int studentID;
private String name;
private char grade;
public Student() {
this.guid = UUID.randomUUID();
}
public Student(final UUID guid, final int studentID, final String name, final char grade) {
super();
this.guid = guid;
this.studentID = studentID;
this.name = name;
this.grade = grade;
}
public Student(final UUID guid) {
this.guid = guid;
}
public final int getStudentId() {
return studentID;
}
public final void setStudentId(final int studentID) {
this.studentID = studentID;
}
public final String getName() {
return name;
}
public final void setName(final String name) {
this.name = name;
}
public final char getGrade() {
return grade;
}
public final void setGrade(final char grade) {
this.grade = grade;
}
public final UUID getGuId() {
return guid;
}
@Override
public final String toString() {
return "Student [guid=" + guid + ", studentID=" + studentID + ", name=" + name + ", grade=" + grade + "]";
}
}
/**
* The MIT License Copyright (c) 2016 Amit Dixit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.io.Serializable;
public final class Student implements Serializable {
private static final long serialVersionUID = 1L;
private int studentId;
private String name;
private char grade;
public Student() {
}
public Student(final int studentId, final String name, final char grade) {
super();
this.studentId = studentId;
this.name = name;
this.grade = grade;
}
public final int getStudentId() {
return studentId;
}
public final void setStudentId(final int studentId) {
this.studentId = studentId;
}
public final String getName() {
return name;
}
public final void setName(final String name) {
this.name = name;
}
public final char getGrade() {
return grade;
}
public final void setGrade(final char grade) {
this.grade = grade;
}
@Override
public boolean equals(final Object inputObject) {
boolean isEqual = false;
/* Check if both objects are same */
if (this == inputObject) {
isEqual = true;
}
/* Check if objects belong to same class */
else if (inputObject != null && getClass() == inputObject.getClass()) {
final Student student = (Student) inputObject;
/* If student id matched */
if (this.getStudentId() == student.getStudentId()) {
isEqual = true;
}
}
return isEqual;
}
@Override
public int hashCode() {
/* Student id is assumed to be unique */
return this.getStudentId();
}
@Override
public final String toString() {
return "Student [studentId=" + studentId + ", name=" + name + ", grade=" + grade + "]";
}
}

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/**
* The MIT License Copyright (c) 2016 Amit Dixit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.util.Optional;
import java.util.UUID;
public interface StudentDataMapper {
public Optional<Student> find(final UUID uniqueID) throws DataMapperException;
public void insert(final Student student) throws DataMapperException;
public void update(final Student student) throws DataMapperException;
public void delete(final Student student) throws DataMapperException;
}
/**
* The MIT License Copyright (c) 2016 Amit Dixit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.util.Optional;
public interface StudentDataMapper {
public Optional<Student> find(final int studentId);
public void insert(final Student student) throws DataMapperException;
public void update(final Student student) throws DataMapperException;
public void delete(final Student student) throws DataMapperException;
}

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@ -1,160 +1,97 @@
/**
* The MIT License Copyright (c) 2016 Amit Dixit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Optional;
import java.util.UUID;
public final class StudentMySQLDataMapper implements StudentDataMapper {
@Override
public final Optional<Student> find(final UUID uniqueID) throws DataMapperException {
try {
/* OracleDriver class cant be initilized directly */
Class.forName("oracle.jdbc.driver.OracleDriver");
/* Create new connection */
final Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/MySQL", "username", "password");
/* Create new Oracle compliant sql statement */
final String statement = "SELECT `guid`, `grade`, `studentID`, `name` FROM `students` where `guid`=?";
final PreparedStatement dbStatement = connection.prepareStatement(statement);
/* Set unique id in sql statement */
dbStatement.setString(1, uniqueID.toString());
/* Execute the sql query */
final ResultSet rs = dbStatement.executeQuery();
while (rs.next()) {
/* Create new student */
final Student student = new Student(UUID.fromString(rs.getString("guid")));
/* Set all values from database in java object */
student.setName(rs.getString("name"));
student.setGrade(rs.getString("grade").charAt(0));
student.setStudentId(rs.getInt("studentID"));
return Optional.of(student);
}
} catch (final SQLException | ClassNotFoundException e) {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Error occured reading Students from MySQL data source.", e);
}
/* Return empty value */
return Optional.empty();
}
@Override
public final void update(final Student student) throws DataMapperException {
try {
/* OracleDriver class cant be initilized directly */
Class.forName("oracle.jdbc.driver.OracleDriver");
/* Create new connection */
final Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/MySQL", "username", "password");
/* Create new Oracle compliant sql statement */
final String statement = "UPDATE `students` SET `grade`=?, `studentID`=?, `name`=? where `guid`=?";
final PreparedStatement dbStatement = connection.prepareStatement(statement);
/* Set java object values in sql statement */
dbStatement.setString(1, Character.toString(student.getGrade()));
dbStatement.setInt(2, student.getStudentId());
dbStatement.setString(3, student.getName());
dbStatement.setString(4, student.getGuId().toString());
/* Execute the sql query */
dbStatement.executeUpdate();
} catch (final SQLException | ClassNotFoundException e) {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Error occured reading Students from MySQL data source.", e);
}
}
@Override
public final void insert(final Student student) throws DataMapperException {
try {
/* OracleDriver class cant be initilized directly */
Class.forName("oracle.jdbc.driver.OracleDriver");
/* Create new connection */
final Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/MySQL", "username", "password");
/* Create new Oracle compliant sql statement */
final String statement = "INSERT INTO `students` (`grade`, `studentID`, `name`, `guid`) VALUES (?, ?, ?, ?)";
final PreparedStatement dbStatement = connection.prepareStatement(statement);
/* Set java object values in sql statement */
dbStatement.setString(1, Character.toString(student.getGrade()));
dbStatement.setInt(2, student.getStudentId());
dbStatement.setString(3, student.getName());
dbStatement.setString(4, student.getGuId().toString());
/* Execute the sql query */
dbStatement.executeUpdate();
} catch (final SQLException | ClassNotFoundException e) {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Error occured reading Students from MySQL data source.", e);
}
}
@Override
public final void delete(final Student student) throws DataMapperException {
try {
/* OracleDriver class cant be initilized directly */
Class.forName("oracle.jdbc.driver.OracleDriver");
/* Create new connection */
final Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/MySQL", "username", "password");
/* Create new Oracle compliant sql statement */
final String statement = "DELETE FROM `students` where `guid`=?";
final PreparedStatement dbStatement = connection.prepareStatement(statement);
/* Set java object values in sql statement */
dbStatement.setString(1, student.getGuId().toString());
/* Execute the sql query */
dbStatement.executeUpdate();
} catch (final SQLException | ClassNotFoundException e) {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Error occured reading Students from MySQL data source.", e);
}
}
}
/**
* The MIT License Copyright (c) 2016 Amit Dixit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.util.List;
import java.util.Optional;
public final class StudentMySQLDataMapper implements StudentDataMapper {
/* Note: Normally this would be in the form of an actual database */
private List<Student> students;
@Override
public final Optional<Student> find(final int studentId) {
/* Compare with existing students */
for (final Student student : this.students) {
/* Check if student is found */
if (student.getStudentId() == studentId) {
return Optional.of(student);
}
}
/* Return empty value */
return Optional.empty();
}
@Override
public final void update(final Student studentToBeUpdated) throws DataMapperException {
/* Check with existing students */
if (this.students.contains(studentToBeUpdated)) {
/* Get the index of student in list */
final int index = this.students.indexOf(studentToBeUpdated);
/* Update the student in list */
this.students.set(index, studentToBeUpdated);
} else {
/* Throw user error */
throw new DataMapperException("Student [" + studentToBeUpdated.getName() + "] is not found");
}
}
@Override
public final void insert(final Student studentToBeInserted) throws DataMapperException {
/* Check with existing students */
if (!this.students.contains(studentToBeInserted)) {
/* Add student in list */
this.students.add(studentToBeInserted);
} else {
/* Throw user error */
throw new DataMapperException("Student already [" + studentToBeInserted.getName() + "] exists");
}
}
@Override
public final void delete(final Student studentToBeDeleted) throws DataMapperException {
/* Check with existing students */
if (this.students.contains(studentToBeDeleted)) {
/* Delete the student from list */
this.students.remove(studentToBeDeleted);
} else {
/* Throw user error */
throw new DataMapperException("Student [" + studentToBeDeleted.getName() + "] is not found");
}
}
}

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/**
* The MIT License Copyright (c) 2016 Amit Dixit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Optional;
import java.util.UUID;
public final class StudentOracleDataMapper implements StudentDataMapper {
@Override
public final Optional<Student> find(final UUID uniqueID) throws DataMapperException {
try {
/* OracleDriver class cant be initilized directly */
Class.forName("oracle.jdbc.driver.OracleDriver");
/* Create new connection */
final Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:Oracle", "username", "password");
/* Create new Oracle compliant sql statement */
final String statement = "SELECT `guid`, `grade`, `studentID`, `name` FROM `students` where `guid`=?";
final PreparedStatement dbStatement = connection.prepareStatement(statement);
/* Set unique id in sql statement */
dbStatement.setString(1, uniqueID.toString());
/* Execute the sql query */
final ResultSet rs = dbStatement.executeQuery();
while (rs.next()) {
/* Create new student */
final Student student = new Student(UUID.fromString(rs.getString("guid")));
/* Set all values from database in java object */
student.setName(rs.getString("name"));
student.setGrade(rs.getString("grade").charAt(0));
student.setStudentId(rs.getInt("studentID"));
return Optional.of(student);
}
} catch (final SQLException | ClassNotFoundException e) {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Error occured reading Students from Oracle data source.", e);
}
/* Return empty value */
return Optional.empty();
}
@Override
public final void update(final Student student) throws DataMapperException {
try {
/* OracleDriver class cant be initilized directly */
Class.forName("oracle.jdbc.driver.OracleDriver");
/* Create new connection */
final Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:Oracle", "username", "password");
/* Create new Oracle compliant sql statement */
final String statement = "UPDATE `students` SET `grade`=?, `studentID`=?, `name`=? where `guid`=?";
final PreparedStatement dbStatement = connection.prepareStatement(statement);
/* Set java object values in sql statement */
dbStatement.setString(1, Character.toString(student.getGrade()));
dbStatement.setInt(2, student.getStudentId());
dbStatement.setString(3, student.getName());
dbStatement.setString(4, student.getGuId().toString());
/* Execute the sql query */
dbStatement.executeUpdate();
} catch (final SQLException | ClassNotFoundException e) {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Error occured reading Students from Oracle data source.", e);
}
}
@Override
public final void insert(final Student student) throws DataMapperException {
try {
/* OracleDriver class cant be initilized directly */
Class.forName("oracle.jdbc.driver.OracleDriver");
/* Create new connection */
final Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:Oracle", "username", "password");
/* Create new Oracle compliant sql statement */
final String statement = "INSERT INTO `students` (`grade`, `studentID`, `name`, `guid`) VALUES (?, ?, ?, ?)";
final PreparedStatement dbStatement = connection.prepareStatement(statement);
/* Set java object values in sql statement */
dbStatement.setString(1, Character.toString(student.getGrade()));
dbStatement.setInt(2, student.getStudentId());
dbStatement.setString(3, student.getName());
dbStatement.setString(4, student.getGuId().toString());
/* Execute the sql query */
dbStatement.executeUpdate();
} catch (final SQLException | ClassNotFoundException e) {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Error occured reading Students from Oracle data source.", e);
}
}
@Override
public final void delete(final Student student) throws DataMapperException {
try {
/* OracleDriver class cant be initilized directly */
Class.forName("oracle.jdbc.driver.OracleDriver");
/* Create new connection */
final Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:Oracle", "username", "password");
/* Create new Oracle compliant sql statement */
final String statement = "DELETE FROM `students` where `guid`=?";
final PreparedStatement dbStatement = connection.prepareStatement(statement);
/* Set java object values in sql statement */
dbStatement.setString(1, student.getGuId().toString());
/* Execute the sql query */
dbStatement.executeUpdate();
} catch (final SQLException | ClassNotFoundException e) {
/* Don't couple any Data Mapper to java.sql.SQLException */
throw new DataMapperException("Error occured reading Students from Oracle data source.", e);
}
}
}
/**
* The MIT License Copyright (c) 2016 Amit Dixit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.iluwatar.datamapper;
import java.util.List;
import java.util.Optional;
public final class StudentOracleDataMapper implements StudentDataMapper {
/* Note: Normally this would be in the form of an actual database */
private List<Student> students;
@Override
public final Optional<Student> find(final int studentId) {
/* Compare with existing students */
for (final Student student : this.students) {
/* Check if student is found */
if (student.getStudentId() == studentId) {
return Optional.of(student);
}
}
/* Return empty value */
return Optional.empty();
}
@Override
public final void update(final Student studentToBeUpdated) throws DataMapperException {
/* Check with existing students */
if (this.students.contains(studentToBeUpdated)) {
/* Get the index of student in list */
final int index = this.students.indexOf(studentToBeUpdated);
/* Update the student in list */
this.students.set(index, studentToBeUpdated);
} else {
/* Throw user error */
throw new DataMapperException("Student [" + studentToBeUpdated.getName() + "] is not found");
}
}
@Override
public final void insert(final Student studentToBeInserted) throws DataMapperException {
/* Check with existing students */
if (!this.students.contains(studentToBeInserted)) {
/* Add student in list */
this.students.add(studentToBeInserted);
} else {
/* Throw user error */
throw new DataMapperException("Student already [" + studentToBeInserted.getName() + "] exists");
}
}
@Override
public final void delete(final Student studentToBeDeleted) throws DataMapperException {
/* Check with existing students */
if (this.students.contains(studentToBeDeleted)) {
/* Delete the student from list */
this.students.remove(studentToBeDeleted);
} else {
/* Throw user error */
throw new DataMapperException("Student [" + studentToBeDeleted.getName() + "] is not found");
}
}
}