Spring Data上---使用傳統方式開發

Spring 資料庫 · 發表 2019-03-15 22:51:48

摘要： Spring Data上---使用傳統方式開發一、什麼是Spring Data 主旨：provide a familiar and consistent,Spring-based programming model for data access 簡化資料庫的訪問。減少資料訪問層...

Spring Data上---使用傳統方式開發

一、什麼是Spring Data

主旨：provide a familiar and consistent,Spring-based programming model for data access

簡化資料庫的訪問。減少資料訪問層的開發量

網址： https://spring.io/projects/spring-data

springdata概覽.jpg

二、Spring Data應用場景

Spring Data包含多個子專案：

Spring Data JPA
Spring Data Mongo DB
Spring Data Redis
Spring Data Solr
...

三、使用傳統方式訪問資料庫

1.使用JDBC

①建立maven專案

建立maven專案1.png

maven2.png

maven3.png

maven4.png

②新增依賴

<!--MySQL Driver-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
<!--junit-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.10</version>
</dependency>

③建立資料庫

create database spring_data;
create table student(
id int not null auto_increment,
name varchar(20) not null,
age int not null,
 primary key(id)
);
insert into student(name,age) values("zhangsan",20);
insert into student(name,age) values("lisi",20);
insert into student(name,age) values("wangwu",20);

④編碼：

JDBC工具類：

package com.hcx.util;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;
/**
 * JDBC工具類
 * 1.獲取連線
 * 2.釋放資源
 * Created by HCX on 2019/3/9.
 */
public class JDBCUtil {

/**
* 獲取Connection
* @return 所獲得到的JDBC的Connection
*/
public static Connection getConnection() throws Exception {
/*String url = "jdbc:mysql://localhost:3306/spring_data";
String user = "root";
String password = "root";
String driverClass = "com.mysql.jdbc.Driver";*/

InputStream inputStream = JDBCUtil.class.getClassLoader().getResourceAsStream("db.properties");
Properties properties = new Properties();
properties.load(inputStream);

String url = properties.getProperty("jdbc.url");
String user = properties.getProperty("jdbc.user");
String password = properties.getProperty("jdbc.password");
String driverClass = properties.getProperty("jdbc.driverClass");

Class.forName(driverClass);
Connection connection = DriverManager.getConnection(url, user, password);
return connection;
}

/**
* 釋放DB相關的資源
* @param resultSet
* @param statement
* @param connection
*/
public static void release(ResultSet resultSet, Statement statement, Connection connection) {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (statement != null) {
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (connection != null) {
try {
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}

db.properties:

jdbc.url = jdbc:mysql://localhost:3306/spring_data
jdbc.user = root
jdbc.password = root
jdbc.driverClass = com.mysql.jdbc.Driver

Student實體：

package com.hcx.domain;

/**
 * Student實體類
 * Created by HCX on 2019/3/10.
 */
public class Student {

//主鍵
private int id;

//姓名
private String name;

//年齡
private int age;

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}
}

StudentDAO:

package com.hcx.dao;

import com.hcx.domain.Student;

import java.util.List;

/**
 * StudentDAO訪問介面
 * Created by HCX on 2019/3/10.
 */
public interface StudentDAO {

/**
* 查詢所有學生
* @return所有學生
*/
public List<Student> query();

/**
* 新增一個學生
* @param student 待新增的學生
*/
public void save(Student student);


}

StudentDAOImpl:

package com.hcx.dao;

import com.hcx.domain.Student;
import com.hcx.util.JDBCUtil;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

/**
 * StudentDAO訪問介面實現類：通過最原始的JDBC的方式操作
 * Created by HCX on 2019/3/10.
 */
public class StudentDAOImpl implements StudentDAO {

@Override
public List<Student> query() {

List<Student> students = new ArrayList<Student>();
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
String sql = "select id,name,age from student";
try {
connection = JDBCUtil.getConnection();
preparedStatement = connection.prepareStatement(sql);
resultSet = preparedStatement.executeQuery();
Student student = null;
while (resultSet.next()) {
int id = resultSet.getInt("id");
String name = resultSet.getString("name");
int age = resultSet.getInt("age");
student = new Student();
student.setId(id);
student.setName(name);
student.setAge(age);
students.add(student);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCUtil.release(resultSet, preparedStatement, connection);
}
return students;
}

@Override
public void save(Student student) {
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
String sql = "insert into student(name,age) values(?,?)";

try {
connection = JDBCUtil.getConnection();
preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1,student.getName());
preparedStatement.setInt(2,student.getAge());
preparedStatement.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCUtil.release(resultSet,preparedStatement,connection);
}
}
}

單元測試：

DataSourceTest：

package com.hcx.util;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.util.Assert;

import javax.sql.DataSource;

/**
 * Created by HCX on 2019/3/10.
 */
public class DataSourceTest {

private ApplicationContext ctx = null;

@Before
public void setup(){
ctx = new ClassPathXmlApplicationContext("beans.xml");
System.out.println("setup");
}

@After
public void tearDown(){
ctx = null;
System.out.println("tearDown");
}

@Test
public void testDataSource(){
DataSource dataSource = (DataSource) ctx.getBean("dataSource");
Assert.notNull(dataSource);
}

@Test
public void testJdbcTemplate(){
System.out.println("testJdbcTemplate");
JdbcTemplate jdbcTemplate = (JdbcTemplate) ctx.getBean("jdbcTemplate");
Assert.notNull(jdbcTemplate);

}


}

JDBCUtilTest:

package com.hcx.util;

import org.junit.Assert;
import org.junit.Test;

import java.sql.Connection;

import static org.junit.Assert.*;

/**
 * Created by HCX on 2019/3/9.
 */
public class JDBCUtilTest {

@Test
public void testGetConnection() throws Exception {
Connection connection = JDBCUtil.getConnection();
Assert.assertNotNull(connection);
}

@Test
public void testRelease() throws Exception {

}
}

2.使用Spring JDBCTemplate

Maven依賴:

<!--spring-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.3.5.RELEASE</version>
</dependency>


<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>

DataSource和JdbcTemplate注入

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.xsd">

<bean id = "dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
<property name="url" value="jdbc:mysql://localhost:3306/spring_data"/>
</bean>

<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"/>
</bean>

<bean id="studentDAO" class="com.hcx.dao.StudentDAOSpringJdbcImpl">
<property name="jdbcTemplate" ref="jdbcTemplate"/>
</bean>
</beans>

springjdbc版本的query和save方法：

StudentDAOSpringJdbcImpl：

package com.hcx.dao;

import com.hcx.domain.Student;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowCallbackHandler;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

/**
 * StudentDAO訪問介面實現類：通過SpringJDBCTemplate的方式
 * Created by HCX on 2019/3/10.
 */
public class StudentDAOSpringJdbcImpl implements StudentDAO {

private JdbcTemplate jdbcTemplate;


@Override
public List<Student> query() {
final List<Student> students = new ArrayList<Student>();
String sql = "select id,name,age from student";

jdbcTemplate.query(sql, new RowCallbackHandler() {
@Override
public void processRow(ResultSet resultSet) throws SQLException {
int id = resultSet.getInt("id");
String name = resultSet.getString("name");
int age = resultSet.getInt("age");

Student student = new Student();
student.setId(id);
student.setName(name);
student.setAge(age);

students.add(student);
}
});
return students;
}

@Override
public void save(Student student) {
String sql = "insert into student(name,age) values(?,?)";
jdbcTemplate.update(sql,new Object[]{student.getName(),student.getAge()});

}

public JdbcTemplate getJdbcTemplate() {
return jdbcTemplate;
}

public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
}

單元測試：

StudentDAOImplTest：

package com.hcx.dao;

import com.hcx.domain.Student;
import org.junit.Test;

import java.util.List;

import static org.junit.Assert.*;

/**
 * Created by HCX on 2019/3/10.
 */
public class StudentDAOImplTest {

@Test
public void testQuery() throws Exception {

StudentDAO studentDAO = new StudentDAOImpl();
List<Student> students = studentDAO.query();

for (Student student : students) {
System.out.println("id:" + student.getId()
+ " ,name:" + student.getName()
+ " ,age:" + student.getAge());
}

}

@Test
public void testSave(){
StudentDAO studentDAO = new StudentDAOImpl();
Student student = new Student();
student.setName("test");
student.setAge(60);
studentDAO.save(student);
}
}

StudentDAOSpringJdbcImplTest:

package com.hcx.dao;

import com.hcx.domain.Student;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

import static org.junit.Assert.*;

/**
 * Created by HCX on 2019/3/10.
 */
public class StudentDAOSpringJdbcImplTest {

private ApplicationContext ctx = null;
private StudentDAO studentDAO = null;

@Before
public void setup(){
ctx = new ClassPathXmlApplicationContext("beans.xml");
studentDAO = (StudentDAO) ctx.getBean("studentDAO");
System.out.println("setup");
}

@After
public void tearDown(){
ctx = null;
System.out.println("tearDown");
}


@Test
public void testQuery() throws Exception {
List<Student> students = studentDAO.query();

for (Student student : students) {
System.out.println("id:" + student.getId()
+ " ,name:" + student.getName()
+ " ,age:" + student.getAge());
}

}

@Test
public void testSave() throws Exception {
Student student = new Student();
student.setName("testSpringJDBC");
student.setAge(80);
studentDAO.save(student);

}

@Test
public void testGetJdbcTemplate() throws Exception {

}

@Test
public void testSetJdbcTemplate() throws Exception {

}
}

3.對比分析

①不夠簡潔

②重複程式碼多

③要開發其他功能，比如分頁等還需要重新封裝。

Demo連線： https://github.com/GitHongcx/springdataDemo

注：本文部分內容來自慕課網

Spring Data上---使用傳統方式開發