为了体现spring jdbc对于单表操作的优势,我专门对dao层做了一个抽离,使得抽离出的核心dao具有通用性。主要技术难点是对于泛型的反射。注意:单表操作中,数据库表的字段要和实体类的属性名保持高度一致,否则可能会出错。

1.整体项目结构

2.pom.xml

<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.xiaog</groupId>
<artifactId>music4j</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging> <properties> <file.encoding>UTF-8</file.encoding>
<spring.version>4.2.2.RELEASE</spring.version>
<mysql.version>5.1.29</mysql.version>
<servlet.version>3.0-alpha-1</servlet.version>
<aspectj.version>1.8.1</aspectj.version>
<commons-codec.version>1.9</commons-codec.version>
<commons-dbcp.version>1.4</commons-dbcp.version>
<hibernate.validator.version>5.0.2.Final</hibernate.validator.version>
<jetty.version>8.1.8.v20121106</jetty.version>
<slf4j.version>1.7.5</slf4j.version>
<testng.version>6.8.7</testng.version>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties> <dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency> <!-- spring 依赖-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency> <dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>${commons-dbcp.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>${servlet.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>${aspectj.version}</version>
</dependency> <dependency>
<groupId>org.testng</groupId>
<artifactId>testng</artifactId>
<version>${testng.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
<scope>test</scope>
</dependency> <!-- https://mvnrepository.com/artifact/jstl/jstl -->
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.1.2</version>
</dependency> <!-- Logback -->
<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-core -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.2.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.logback-extensions/logback-ext-spring -->
<dependency>
<groupId>org.logback-extensions</groupId>
<artifactId>logback-ext-spring</artifactId>
<version>0.1.4</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.25</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.slf4j/jcl-over-slf4j -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>1.7.25</version>
</dependency>
</dependencies> <build>
<defaultGoal>compile</defaultGoal>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin> <groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.1</version>
<configuration>
<port>9999</port>
<path>/music4j</path>
<uriEncoding>UTF-8</uriEncoding>
<finalName>music4j</finalName>
<server>tomcat7</server>
</configuration>
</plugin> </plugins>
</build>
</project>

3.各配置文件

(1)spring-context.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" xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd"> <!-- 扫描类包,将标注Spring注解的类自动转化Bean,同时完成Bean的注入 -->
<context:component-scan base-package="com.music4j.dao"/>
<context:component-scan base-package="com.music4j.service"/> <!-- 配置数据源 -->
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close"
p:driverClassName="com.mysql.jdbc.Driver"
p:url="jdbc:mysql://localhost:3306/ssjdbc"
p:username="root"
p:password="root"
/> <!-- 配置Jdbc模板 -->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"
p:dataSource-ref="dataSource" /> <!-- 配置事务管理器 -->
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
p:dataSource-ref="dataSource" /> <!-- 通过AOP配置提供事务增强,让service包下所有Bean的所有方法拥有事务 -->
<aop:config proxy-target-class="true">
<aop:pointcut id="serviceMethod"
expression="(execution(* com.music4j.service..*(..))) and (@annotation(org.springframework.transaction.annotation.Transactional))" />
<aop:advisor pointcut-ref="serviceMethod" advice-ref="txAdvice" />
</aop:config>
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="*" />
</tx:attributes>
</tx:advice> </beans>

(2)spring-mvc.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"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!--配置组件扫描 应用 sprnig 注解-->
<context:component-scan base-package="com.music4j.controller"/> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
p:viewClass="org.springframework.web.servlet.view.JstlView"
p:prefix="/"
p:suffix=".jsp"
/> </beans>

(3)logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<!-- 控制台输出 -->
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<!-- 日志输出编码 -->
<Encoding>UTF-8</Encoding>
<layout class="ch.qos.logback.classic.PatternLayout">
<!--格式化输出:%d表示日期,%thread表示线程名,%-5level:级别从左显示5个字符宽度%msg:日志消息,%n是换行符-->
<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n
</pattern>
</layout>
</appender>
<!-- 日志输出级别 -->
<root level="INFO">
<appender-ref ref="STDOUT" />
</root>
</configuration>

(4)web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
<display-name>music4j</display-name> <!-- spring配置文件 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-context.xml</param-value>
</context-param>
<!-- spring监听器 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener> <!-- 字符编码过滤器 spring web自动提供一个 -->
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping> <!-- spring mvc 配置 【中央控制器/前端控制器/总控】 -->
<servlet>
<servlet-name>spring-mvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 配置Spring mvc下的配置文件的位置和名称 -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- 可以配置扩展名,*.do -->
<servlet-mapping>
<servlet-name>spring-mvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping> <!-- 添加日志监听器 -->
<context-param>
<param-name>logbackConfigLocation</param-name>
<param-value>classpath:logback.xml</param-value>
</context-param>
<listener>
<listener-class>ch.qos.logback.ext.spring.web.LogbackConfigListener</listener-class>
</listener> <welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list> </web-app>

4.数据库

create database ssjdbc;//创建ssjdbc数据库

//创建user表
CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(32) DEFAULT NULL,
`password` varchar(32) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8; //插入数据3条
insert into user(username,password) values (1001,123),(1002,456),(1003,789);

5.编写工具类SqlFactory,用于生成动态sql语句,类似mybatis的动态sql语句

package com.music4j.util;

import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map; import org.slf4j.Logger;
import org.slf4j.LoggerFactory; public class SqlFactory { private String tableName; public Object[] params; public SqlFactory(Class<?> clazz) {
tableName = clazz.getSimpleName().toLowerCase();
} private final static Logger logger = LoggerFactory.getLogger(SqlFactory.class); private Map<String,Object> objectToMap(Object entity) {
Field[] fields = entity.getClass().getDeclaredFields();
Map<String,Object> map = new HashMap<String,Object>();
for(Field field : fields) {
field.setAccessible(true);//设置属性可访问
Object value = null;
try {
value = field.get(entity);
} catch (IllegalArgumentException | IllegalAccessException e) {
e.printStackTrace();
}
if(value != null) {
map.put(field.getName(), value);
}
}
return map;
} public String getDeleteSql() {
StringBuilder sql = new StringBuilder("delete from ").append(tableName).append(" where id = ?");
logger.info(sql.toString());
return sql.toString();
} public String getSelectOneSql() {
StringBuilder sql = new StringBuilder("select * from ").append(tableName).append(" where id = ?");
logger.info(sql.toString());
return sql.toString();
} public String getInsertSql(Object entity) {
Map<String,Object> map = this.objectToMap(entity);
map.remove("id");
params = new Object[map.size()];
StringBuilder stringBuiler = new StringBuilder("insert into ").append(tableName).append("(");
for(String key : map.keySet()) {
stringBuiler.append(key).append(",");
}
stringBuiler.deleteCharAt(stringBuiler.length()-1).append(") values (");
int i = 0;
for(String key : map.keySet()) {
stringBuiler.append("?,");
params[i] = map.get(key);
i++;
}
stringBuiler.deleteCharAt(stringBuiler.length()-1).append(")");
map = null;
logger.info(stringBuiler.toString());
return stringBuiler.toString();
} public String getUpdateSql(Object entity) {
Map<String,Object> map = this.objectToMap(entity);
params = new Object[map.size()];
params[params.length-1] = map.remove("id");
StringBuilder stringBuiler = new StringBuilder("update ").append(tableName).append(" set ");
int i = 0;
for(String key : map.keySet()) {
stringBuiler.append(key).append("=?,");
params[i] = map.get(key);
i++;
}
stringBuiler.deleteCharAt(stringBuiler.length()-1).append(" where id = ?");
map = null;
logger.info(stringBuiler.toString());
return stringBuiler.toString();
} public String getSelectList(Object entity) {
Map<String,Object> map = this.objectToMap(entity);
map.remove("id");
params = new Object[map.size()];
StringBuilder stringBuiler = new StringBuilder("select * from ").append(tableName).append(" where ");
int i = 0;
for(String key : map.keySet()) {
stringBuiler.append(key).append("=? and ");
params[i] = map.get(key);
i++;
}
stringBuiler.delete(stringBuiler.length()-4, stringBuiler.length());
map = null;
logger.info(stringBuiler.toString());
return stringBuiler.toString();
}
}

6.编写核心dao接口及其实现类

package com.music4j.core.dao;

import java.util.List;

public interface CoreDao<T> {
int insert(T t);
int delete(int id);
int update(T t);
T getOne(int id);
List<T> getList(T t);
}
package com.music4j.core.dao.impl;

import java.lang.reflect.ParameterizedType;
import java.util.List; import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate; import com.music4j.core.dao.CoreDao;
import com.music4j.util.SqlFactory; public class CoreDaoImpl<T> implements CoreDao<T> { @Autowired
private JdbcTemplate jdbcTemplate; private SqlFactory sqlFactory; private Class<T> clazz; @SuppressWarnings("unchecked")
public CoreDaoImpl() {
this.clazz = (Class<T>)((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
sqlFactory = new SqlFactory(this.clazz);
} @Override
public int insert(T t) {
return jdbcTemplate.update(sqlFactory.getInsertSql(t),sqlFactory.params);
} @Override
public int delete(int id) {
return jdbcTemplate.update(sqlFactory.getDeleteSql(),id);
} @Override
public int update(T t) {
return jdbcTemplate.update(sqlFactory.getUpdateSql(t),sqlFactory.params);
} @Override
public T getOne(int id) {
return jdbcTemplate.queryForObject(sqlFactory.getSelectOneSql(), new BeanPropertyRowMapper<T>(clazz),id);
} @Override
public List<T> getList(T t) {
return jdbcTemplate.query(sqlFactory.getSelectList(t),new BeanPropertyRowMapper<T>(clazz),sqlFactory.params);
} }

7.编写实体类dao接口及其实现,因为已经有了核心接口和实现,所以只需继承即可

package com.music4j.dao;

import com.music4j.core.dao.CoreDao;
import com.music4j.entity.User; public interface UserDao extends CoreDao<User> {
}
package com.music4j.dao.impl;

import org.springframework.stereotype.Repository;

import com.music4j.core.dao.impl.CoreDaoImpl;
import com.music4j.dao.UserDao;
import com.music4j.entity.User; @Repository
public class UserDaoImpl extends CoreDaoImpl<User> implements UserDao { }

8.编写service接口及其实现

package com.music4j.service;

import com.music4j.entity.User;

public interface UserService {
User login(User user);
}
package com.music4j.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service; import com.music4j.dao.UserDao;
import com.music4j.entity.User;
import com.music4j.service.UserService; @Service
public class UserServiceImpl implements UserService { @Autowired
private UserDao userDao; @Override
public User login(User user) {
List<User> users = userDao.getList(user);
if(users!=null&&users.size()>0) {
return users.get(0);
}else {
return null;
}
} }

9.编写controller

package com.music4j.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping; import com.music4j.entity.User;
import com.music4j.service.UserService; @Controller
@RequestMapping("/user")
public class UserController { @Autowired
private UserService userService; @RequestMapping(value = "/login",params= {"username","password","username!=","password!="})
public String login(Model model,User user) {
user = userService.login(user);
System.out.println("user="+user);
model.addAttribute("user", user);
return "result";
} }

10.编写jsp页面测试登录

(1)index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="user/login" method="post">
<div>
<label>username</label>
<input type="text" name="username"/>
</div>
<div>
<label>password</label>
<input type="password" name="password"/>
</div>
<div>
<input type="submit" value="登录">
</div>
</form>
</body>
</html>

(2)result.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
username=${user}
</body>
</html>

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