如今的Java项目,如果还使用传统的把jar包复制到目录下这种原始的方式,对于依赖管理来说实在是灾难。对某个功能需要引入某种技术包,但是你不确定是否已存在,如果分类好的话还好找,若是杂在一堆不仅头大,还身心俱疲。Maven旨在解决依赖问题,让项目结构变得精简,而Spring解决了项目中Bean的管理以及各种配置文件配置的功能轻松读入等问题,对于Java项目来说确实是福音。对于一个Web项目来说,必然需要数据库的读写,JdbcTemplate是一个Spring实现的Jdbc Support。对于之前必然依赖ORM的项目来说,这个组件表现得十分的轻便以及可伸缩,不需要写Mapping就使用HashMap的可伸缩性,实在是小型团队以及敏捷公司的良伴。加之报错栈十分的简单,一个数据库过程就只会在Dao里写一个sql和加载参数,最后执行,如果出错就只有在sql和参数中排查即可,比起之前在Mybatis里各种翻配置文件的时期,简直就是天堂地狱。
好了,说了这么多优劣,今天来写写要做笔记的项目。Java Web项目 + Maven项目依赖 + Spring + Spring MVC + JdbcTemplate + dbcp2连接池。其实中间三项都是Spring里面含有的。
- 开始
下载一个IDEA
IDE,这个IDE比之于Eclipse,一开始会有些不习惯,但是用了一段时间之后就觉得它的各种细节处理很受好评,特别是对Maven项目的支持。
然后新建一个Maven Java 项目,选择Web模板。虽然IDE版本不一样,但是模板之类还有新建模板的步骤都是没怎么变化的。
选择创建按照Web模板,和JDK版本。
这个group id 的官方解释是组织id,我的理解是比如一个项目的组织为taobao,jd这样子,算是项目组的最高id。artifact id官方解释是项目唯一标识,算是在组织之下的唯一项目标志,创建项目之后会发现项目名称是这个artifact id。
之后的一步是选择maven版本,maven仓库之类的,自行斟酌。
在我的环境里,创建完项目之后,结构并不是我想象的那样,查了资料,加上等待maven加载之后,项目的结构变成了我熟悉的那种结构,就是少了java文件夹。创建项目之后,maven会一直下载jar包,等它加载完成才会变成熟悉的maven结构。
这里在配置的时候注意,classpath是java目录下,如果在src/main下面如果没有java可以自己建一个(我就是没有这个文件夹)。
接下来,项目加载完成了,需要导入依赖包了,编辑pom.xml文件。(在这里保存我本地项目的配置)
<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>TestProject</groupId>
<artifactId>test1</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>test1 Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<!-- spring版本号 -->
<spring.version>4.1.1.RELEASE</spring.version>
<!-- mybatis版本号 -->
<mybatis.version>3.2.6</mybatis.version>
<!-- log4j日志文件管理包版本 -->
<slf4j.version>1.7.7</slf4j.version>
<log4j.version>1.2.17</log4j.version>
<!-- jackson包版本 -->
<jackson.version>2.5.0</jackson.version>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!--单元测试依赖 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<!-- 表示开发的时候引入,发布的时候不会加载此包 -->
<scope>test</scope>
</dependency>
<!--spring单元测试依赖 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
<scope>test</scope>
</dependency>
<!-- springMVC核心包 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- spring核心包 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</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-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-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>4.0.9.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- AOP begin -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.7.4</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.7.4</version>
</dependency>
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>3.1</version>
</dependency>
<!-- AOP end -->
<!-- Mysql数据库驱动包 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.34</version>
</dependency>
<!-- log start -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>${log4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${slf4j.version}</version>
</dependency>
<!-- log end -->
<!--servlet-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
<scope>provided</scope>
</dependency>
<!-- 映入JSON -->
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-asl</artifactId>
<version>1.9.13</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.13</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>net.sf.json-lib</groupId>
<artifactId>json-lib</artifactId>
<version>2.1</version>
<classifier>jdk15</classifier>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-dbcp2</artifactId>
<version>2.0</version>
</dependency>
</dependencies>
<build>
<finalName>test1</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
<!-- 解决Maven项目编译后classes文件中没有.xml问题 -->
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build></project>
待加载完成后,配置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" id="WebApp_ID" version="3.0">
<welcome-file-list>
<welcome-file>/index.html</welcome-file>
</welcome-file-list>
<display-name>test1</display-name>
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:resources/spring-mvc.xml</param-value>
</init-param>
</servlet>
<!-- 拦截设置 -->
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<!-- 此处可以可以配置成*.do,对应struts的后缀习惯 -->
<url-pattern>/</url-pattern>
</servlet-mapping>
<!--把applicationContext.xml加入到配置文件中-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:resources/applicationContext.xml</param-value>
</context-param>
<!--spring启动监听器-->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!--日志配置-->
<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>classpath:resources/log4j.properties</param-value>
</context-param></web-app>
需要配置文件:spring bean配置文件,spring mvc配置文件,jdbc.properties,log4j配置文件。统一写在resource下。
此时路径是 classpath:resource/*.xml。
其他几份配置文件。
<?xml version="1.0" encoding="UTF-8"?><beans
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:cache="http://www.springframework.org/schema/cache" xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-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/cache http://www.springframework.org/schema/cache/spring-cache-4.0.xsd">
<!-- 进行主数据库的事务配置,采用默认策略 -->
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
<!-- 引入jdbc配置文件 -->
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:resources/jdbc.properties</value>
</list>
</property>
</bean>
<!-- 配置数据源 使用dbcp连接池-->
<bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource" destroy-method="close">
<property name="url">
<value>${jdbc.url}</value>
</property>
<property name="driverClassName" value="${jdbc.driverClass}"/>
<property name="username">
<value>${jdbc.username}</value>
</property>
<property name="password">
<value>${jdbc.password}</value>
</property>
<!--initialSize: 初始化连接-->
<property name="initialSize" value="25"/>
<property name="maxTotal" value="20"/>
<property name="maxIdle" value="5"/>
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref ="dataSource"/>
</bean>
<!--Dao Config-->
<bean id="demoDao" class="Dao.DemoDao">
<property name="jdbcTemplate" ref ="jdbcTemplate"/>
</bean></beans>
<?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:mvc="http://www.springframework.org/schema/mvc"
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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
<description>Spring MVC Configuration</description>
<mvc:annotation-driven/>
<!-- scan the package and the sub package -->
<context:component-scan base-package="controller"/>
<!-- don't handle the static resource -->
<mvc:default-servlet-handler />
<!-- if you use annotation you must configure following setting -->
<mvc:annotation-driven />
<!-- configure the InternalResourceViewResolver -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
id="internalResourceViewResolver">
<!-- 前缀 -->
<property name="prefix" value="" />
<!-- 后缀 -->
<property name="suffix" value="" />
</bean></beans>
### \u8BBE\u7F6E###
log4j.rootLogger=D,E,CONSOLE
###set spring not output under error rank
log4j.logger.org.springframework=ERROR
###Console print
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Target=System.out
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] -[ %l ] %m%n
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] -[ %l ] %m%n
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File = ${catalina.base}/InvoiceLogs/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 ] -[ %l ] %m%n
jdbc.driverClass = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql://localhost:3306/Test?useUnicode=true&&characterEncoding=UTF-8
jdbc.username = 账号
jdbc.password = 密码
配置完成之后写个demo然后看看运行正常么。
package controller;
import Dao.DemoDao;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.ResponseBody;import java.util.List;import java.util.Map;
/**
* Created by MacBook on 2017/11/5.
*/
@RequestMapping("/first")
@Controllerpublic class FirstController {
@Autowired
private DemoDao demoDao;
@RequestMapping(value="/sayHello",produces="text/html;charset=UTF-8",method = RequestMethod.GET)
public @ResponseBody String sayHello(){
return "hello";
}
@RequestMapping(value="/testDao",produces="text/html;charset=UTF-8",method = RequestMethod.GET)
public @ResponseBody String testDao(){
StringBuilder sb = new StringBuilder();
List<Map<String,Object>> arr = demoDao.getAddressAll();
if(arr != null){
for(Map<String,Object> map : arr){
sb.append("id :"+map.get("id").toString()).append("\t");
sb.append("address :"+map.get("address").toString()).append("\t");
sb.append("remart :"+map.get("remark").toString()).append("\t");
sb.append("\r\n");
}
}else {
sb.append("no data");
}
return sb.toString();
}
}
package Dao;
import org.springframework.jdbc.core.JdbcTemplate;
import java.util.List;import java.util.Map;
/**
* Created by MacBook on 2017/11/5.
*/public class DemoDao {
private JdbcTemplate jdbcTemplate;
//测试获取address信息
public List<Map<String,Object>> getAddressAll(){
String sql = "select * from address";
try{
return jdbcTemplate.queryForList(sql);
}catch (Exception e){
e.printStackTrace();
return null;
}
}
public JdbcTemplate getJdbcTemplate() {
return jdbcTemplate;
}
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
}
测试运行正常,到此笔记结束。
对jdbcTemplate的泛型数据处理那是服服帖帖的,数据库返回的数据,要不就是一列要不就是多列要不就是没有。List<Map<String,Object>>为多列数据,Map<String,Object>为一列数据,没有会抛异常。有点近乎于nosql的领域,需要什么拿什么这种感觉。舍弃了繁重的数据封装model层。
- 结尾
本来新建项目是件很简单的事情,但是上周弄了快一个下午,所以特此记录一下。