搭建项目
pom文件
<?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.snail.test</groupId>
<artifactId>Spring-MVC</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombok.version}</version>
</dependency>
<!-- JSR-303 start -->
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>${validation-api.version}</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>${hibernate-validator.version}</version>
</dependency>
<!-- JSR-303 end -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junitversion}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.4.1</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.4.1.1</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jms</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-oxm</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${springversion}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
<version>3.1</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.4</version>
</dependency>
<!-- 添加mysql驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.12</version>
</dependency>
</dependencies>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<springversion>4.1.0.RELEASE</springversion>
<junitversion>3.8.1</junitversion>
<project.jdk.version>1.7</project.jdk.version>
<hibernate-validator.version>5.2.4.Final</hibernate-validator.version>
<validation-api.version>1.1.0.Final</validation-api.version>
<lombok.version>1.14.8</lombok.version>
</properties>
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
<testResources>
<testResource>
<directory>src/test/resources</directory>
<filtering>true</filtering>
</testResource>
</testResources>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>${project.jdk.version}</source>
<encoding>${project.build.sourceEncoding}</encoding>
<target>${project.jdk.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.4.3</version>
<configuration>
<encoding>${project.build.sourceEncoding}</encoding>
<nonFilteredFileExtensions>
<nonFilteredFileExtension>
dat
</nonFilteredFileExtension>
<nonFilteredFileExtension>
xls
</nonFilteredFileExtension>
<nonFilteredFileExtension>
xlsx
</nonFilteredFileExtension>
</nonFilteredFileExtensions>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-source-plugin</artifactId>
<version>2.2.1</version>
<configuration>
<attach>true</attach>
</configuration>
<executions>
<execution>
<phase>install</phase>
<goals>
<goal>jar</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
jdbc.properties
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/student
jdbc.username=root
jdbc.password=root
dispatch-servlet
<?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:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc" 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-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<context:component-scan base-package="transaction"/>
<mvc:annotation-driven/>
<context:property-placeholder location="classpath:jdbc.properties"/>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close"
p:driverClassName="${jdbc.driverClassName}"
p:url="${jdbc.url}"
p:username="${jdbc.username}"
p:password="${jdbc.password}"/>
<bean id="jdbcTemplate"
class="org.springframework.jdbc.core.JdbcTemplate"
p:dataSource-ref="dataSource"/>
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
p:dataSource-ref="dataSource"/>
<tx:annotation-driven transaction-manager="transactionManager"/>
<!-- 启动Spring MVC的注解功能,完成请求和注解POJO的映射-->
<!--<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>-->
<!-- 模型视图名称的解析,即在模型视图名称添加前后缀 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
p:prefix="/WEB-INF/jsp/" p:suffix=".jsp"/>
</beans>
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_2_5.xsd"
id="WebApp_ID" version="2.5">
<display-name>hello</display-name>
<!--Spring集成Web环境-->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<!-- POST中文乱码过滤器 -->
<filter>
<filter-name>CharacterEncodingFilter</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>
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:transaction_dispatcher-servlet.xml</param-value>
</init-param>
<load-on-startup>0</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
service
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import java.sql.SQLException;
@Controller
public class UserService {
@Autowired
private JdbcTemplate jdbcTemplate;
@RequestMapping("/login")
@Transactional
public String login(String userName, String password) throws Exception {
String sql = "UPDATE student SET name = ? WHERE id = ? ";
jdbcTemplate.update(sql, "111", 2);
if (isRightUser(userName, password)) {
sql = "UPDATE student SET name = ? WHERE id = ? ";
jdbcTemplate.update(sql, "222", 2);
return "success";
} else {
return "fail";
}
}
private boolean isRightUser(String userName, String password) throws Exception {
throw new SQLException();
// return true;
}
}
注意点
@Transactional
事务传播行为:PROPAGATION_REQUIRED
事务隔离级别:ISOLATION_DEFAULT
读写事务属性:读/写事务
超时时间:依赖底层事务系统的默认值
回滚设置:任何运行期异常引发回滚,任何检查型异常不会引发回滚
read-only="true"
概念:从这一点设置的时间点开始(时间点a)到这个事务结束的过程中,其他事务所提交的数据,该事务将看不见!(查询中不会出现别人在时间点a之后提交的数据)
应用场合
一次执行单条查询语句,则没有必要启用事务支持,数据库默认支持SQL执行期间的读一致性;
一次执行多条查询语句,例如统计查询,报表查询,在这种场景下,多条查询SQL必须保证整体的读一致性,否则,在前条SQL查询之后,后条SQL查询之前,数据被其他用户改变,则该次整体的统计查询将会出现读数据不一致的状态,此时,应该启用事务支持。
注意是一次执行多次查询来统计某些信息,这时为了保证数据整体的一致性,要用只读事务
怎样设置:
对于只读查询,可以指定事务类型为readonly,即只读事务。
由于只读事务不存在数据的修改,因此数据库将会为只读事务提供一些优化手段,例如Oracle对于只读事务,不启动回滚段,不记录回滚log。
- 注解 @Transactional(readOnly = true)
在将事务设置成只读后,相当于将数据库设置成只读数据库,此时若要进行写的操作,会出现错误。