Spring 練習 通過學習spring的基礎知識,瞭解了Spring為了降低Java開發的複雜性,採取了以下4種關鍵策略: 基於POJO的輕量級和最小侵入性編程; 通過依賴註入和麵向介面實現松耦合; 基於切麵和慣例進行聲明式編程; 通過切麵和模板減少樣板式代碼。 下麵將做一個spring的練習de ...
Spring 練習
通過學習spring的基礎知識,瞭解了Spring為了降低Java開發的複雜性,採取了以下4種關鍵策略:
- 基於POJO的輕量級和最小侵入性編程;
- 通過依賴註入和麵向介面實現松耦合;
- 基於切麵和慣例進行聲明式編程;
- 通過切麵和模板減少樣板式代碼。
下麵將做一個spring的練習demo,進一步熟悉spring的ioc和aop的使用方法,以及使用spring模板的優點。
Demo說明
將構建一個用戶更刪改查的項目,其中對項目進行分層,通過spring的ioc的特性進行依賴註入。並使用aop特性增加日誌操作。資料庫操作使用了spring的jdbcTemplate簡化資料庫操作。
項目結構
創建一個maven項目,並構建如下文件夾
--springdemo
--src
--main
--java
--aop
--conf
--dao
--service
--entity
--resources
--test
--java
--service
pom.xml
使用到的依賴有spring,slf4j,log4j,mysql-connector等。
pom.xml如下:
<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.tong</groupId>
<artifactId>spring-demo</artifactId>
<version>1.0-SNAPSHOT</version>
<name>spring-demo</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<spring.version>4.3.2.RELEASE</spring.version>
<slf4j.version>1.7.24</slf4j.version>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!-- spring 核心 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- spring aop -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.8</version>
</dependency>
<!-- spring junit -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- spring jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- mysql 驅動 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.22</version>
</dependency>
<!-- slf4j -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${slf4j.version}</version>
</dependency>
</dependencies>
<build>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
<!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
<plugin>
<artifactId>maven-site-plugin</artifactId>
<version>3.7.1</version>
</plugin>
<plugin>
<artifactId>maven-project-info-reports-plugin</artifactId>
<version>3.0.0</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
項目分層說明
entity層
entity層即包含User.jave實體類,是一個POJO類,僅包含屬性,構造器和setter,getter方法。
如下:
package com.tong.entity;
/**
* User實體類
*
* @author tongl
* @version 1.0 11/11/2019
*/
public class User {
Integer id;
String name;
String sex;
Integer age;
public User() {
}
public User(Integer id, String name, String sex, Integer age) {
this.id = id;
this.name = name;
this.sex = sex;
this.age = age;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "User{" + "id=" + this.id + ", name='" + this.name + '\'' + ", sex='" + this.sex + '\'' + ", age=" + this.age + '}';
}
}
dao層
DAO層主要是做數據持久層的工作,負責與資料庫進行聯絡的一些任務都封裝在此,DAO層的設計首先是設計DAO的介面,然後在Spring的配置文件中定義此介面的實現類,然後就可在模塊中調用此介面來進行數據業務的處理,而不用關心此介面的具體實現類是哪個類,顯得結構非常清晰,DAO層的數據源配置,以及有關資料庫連接的參數都在Spring的配置文件中進行配置。
包括介面和實現。
UserDao.java
package com.tong.dao;
import com.tong.entity.User;
/**
* 持久化數據層介面
*
* @author tongl
*/
public interface UserDao {
/**
* 新增用戶
*
* @param user 用戶
*/
void addUser(User user);
/**
* 根據id刪除用戶
*
* @param id id
*/
void deleteUser(int id);
/**
* 根據id查找用戶
*
* @param id 用戶id
*/
User getUser(int id);
/**
* 更新用戶信息
*
* @param user 用戶
*/
void updateUser(User user);
}
UserDaoImpl.java
package com.tong.dao.impl;
import com.tong.dao.UserDao;
import com.tong.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import java.util.List;
/**
* 持久化數據層實現
*
* @author tongl
*/
@Repository
public class UserDaoImpl implements UserDao {
@Autowired
private JdbcTemplate jdbcTemplate;
/**
* 新增用戶
*
* @param user 用戶
*/
@Override
public void addUser(User user) {
jdbcTemplate.update("insert into t_user values(?,?,?,?)", user.getId(), user.getName(), user.getSex(), user.getAge());
}
/**
* 根據id刪除用戶
*
* @param id id
*/
@Override
public void deleteUser(int id) {
jdbcTemplate.update("delete from t_user where id = ?", id);
}
/**
* 根據id查找用戶
*
* @param id 用戶id
* @return user
*/
@Override
public User getUser(int id) {
List<User> users = jdbcTemplate.query("select * from t_user where id = ?",
new BeanPropertyRowMapper<User>(User.class), id);
if (users != null && users.size() > 0) {
return users.get(0);
}
return null;
}
/**
* 更新用戶
*
* @param user 用戶
*/
@Override
public void updateUser(User user) {
jdbcTemplate.update("update t_user set name = ?, age = ?, sex = ? where id = ?",
user.getName(), user.getAge(), user.getSex(), user.getId());
}
}
service層
Service層主要負責業務模塊的邏輯應用設計。同樣是首先設計介面,再設計其實現的類,接著再Spring的配置文件中配置其實現的關聯。這樣我們就可以在應用中調用Service介面來進行業務處理。Service層的業務實現,具體要調用到已定義的DAO層的介面,封裝Service層的業務邏輯有利於通用的業務邏輯的獨立性和重覆利用性,程式顯得非常簡潔。
UserService.java
package com.tong.service;
import com.tong.entity.User;
/**
* 服務層介面
*
* @author tongl
* @version 1.0 10/10/2019
*/
public interface UserService {
/**
* 新增修改用戶
*
* @param user 用戶
*/
void saveUser(User user);
/**
* 刪除用戶
*
* @param id 用戶id
*/
void deleteUser(int id);
}
UserServiceImpl.java
package com.tong.service.impl;
import com.tong.dao.UserDao;
import com.tong.entity.User;
import com.tong.service.UserService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* 服務層實現
*
* @author tongl
*/
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserDao userDao;
Logger logger = LoggerFactory.getLogger(UserServiceImpl.class);
/**
* 添加修改用戶
*
* @param user 用戶
*/
@Override
public void saveUser(User user) {
Integer id = user.getId();
User u = userDao.getUser(id);
if (u == null) {
// 如果查詢user為空,那麼新增用戶
userDao.addUser(user);
logger.info("新增用戶:{}", user);
} else {
// 如果user不為空,那麼更改用戶
userDao.updateUser(user);
logger.info("修改用戶信息:{}", user);
}
}
/**
* 刪除用戶
*
* @param id 用戶id
*/
@Override
public void deleteUser(int id) {
User user = userDao.getUser(id);
userDao.deleteUser(id);
logger.info("刪除用戶:{}", user);
}
}
aop層
實現日誌切麵
Log.java
package com.tong.aop;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.stereotype.Component;
/**
* 日誌服務
*
* @author tongl
*/
@Component
@ComponentScan(basePackages = {"com.fiberhome"})
@Aspect
@EnableAspectJAutoProxy
public class Log {
Logger logger = LoggerFactory.getLogger(Log.class);
/**
* 配置後置通知:新增/修改用戶列印日誌
*/
@AfterReturning("execution(* com.tong.service.*.saveUser(..))")
public void addLog() {
logger.info("添加/修改用戶操作-日誌記錄");
}
/**
* 配置後置通知:刪除用戶列印日誌
*/
@AfterReturning("execution(* com.tong.service.*.deleteUser(..))")
public void deleteLog() {
logger.info("刪除用戶操作-日誌記錄");
}
}
config
本項目使用Java配置方式,這裡是Java配置文件。
DataConfig.java
package com.tong.conf;
import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.*;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
@Configuration
@ComponentScan(basePackages = {"com.tong"})
@PropertySource(value = "classpath:db.properties")
@Scope("singleton")
public class DataConfig {
@Value("${jdbc.driver}")
private String driver;
@Value("${jdbc.url}")
private String url;
@Value("${jdbc.username}")
private String username;
@Value("${jdbc.password}")
private String password;
/**
* 創建連接池
*
* @return dataSource
*/
@Bean
public DataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(driver);
dataSource.setUrl(url);
dataSource.setUsername(username);
dataSource.setPassword(password);
return dataSource;
}
@Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
return new PropertySourcesPlaceholderConfigurer();
}
@Bean
public JdbcTemplate getJdbcTemplate(DataSource dataSource) {
return new JdbcTemplate(dataSource);
}
}
測試類
UserServiceTest
package com.tong.service;
import com.tong.conf.DataConfig;
import com.tong.entity.User;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
/**
* 用戶服務測試類
* @author tongl
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {DataConfig.class})
public class UserServiceTest {
@Autowired
private UserService userService;
/**
* 添加用戶測試
*/
@Test
public void testAddUser(){
User user = new User(1001,"張三","男",17);
User user2 = new User(1001,"張三","男",20);
User user3 = new User(1012,"張四","男",18);
//System.out.println(user);
userService.saveUser(user);
userService.saveUser(user2);
userService.saveUser(user3);
}
/**
* 刪除用戶測試
*/
@Test
public void testDeleteUser(){
userService.deleteUser(1001);
userService.deleteUser(1002);
}
}
resources文件
db.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///user?useUnicode=true&characterEncoding=utf-8
jdbc.username=root
jdbc.password=root
log4j.properties
### 設置###
log4j.rootLogger = info,stdout,D,E
### 輸出信息到控制抬 ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n
### 輸出DEBUG 級別以上的日誌到logs/debug.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = logs/debug.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n
### 輸出ERROR 級別以上的日誌到logs/error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =logs/error.log
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n