个人仿制的SSM框架

1、Pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.wnx.mall.tiny</groupId><artifactId>web-my-ssm</artifactId><version>0.0.1-SNAPSHOT</version><name>web-my-ssm</name><description>个人仿制的SSM框架</description><properties><java.version>1.8</java.version></properties><dependencies><!--servlet--><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.1.0</version><scope>provided</scope></dependency><!--junit--><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.13.2</version><scope>test</scope></dependency><!--mysql--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.27</version></dependency><!--thymeleaf--><dependency><groupId>org.thymeleaf</groupId><artifactId>thymeleaf</artifactId><version>3.0.14.RELEASE</version></dependency><!--lombok--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.22</version><scope>provided</scope></dependency></dependencies><build><resources><resource><directory>src/main/java</directory><includes><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>true</filtering></resource><resource><directory>src/main/resources</directory><includes><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>true</filtering></resource></resources><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><configuration><source>8</source><target>8</target><!--反射能得到真的方法名--><compilerArgs><arg>-parameters</arg></compilerArgs></configuration></plugin></plugins></build>
</project>

2、Spring配置文件

放置在resources\applicationContext.xml

<?xml version="1.0" encoding="utf-8"?>
<beans><bean id="pmsBrandMapper" class="com.wnx.mall.tiny.mapper.impl.PmsBrandMapperImpl"/><bean id="PmsBrandService" class="com.wnx.mall.tiny.service.impl.PmsBrandServiceImpl"><property name="pmsBrandMapper" ref="pmsBrandMapper"/></bean><bean id="brand" class="com.wnx.mall.tiny.controller.PmsBrandController"><property name="fruitService" ref="fruitService"/></bean>
</beans>

3、Web.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"version="4.0"><!-- 配置上下文参数 --><context-param><param-name>view-prefix</param-name><param-value>/</param-value></context-param>d<context-param><param-name>view-suffix</param-name><param-value>.html</param-value></context-param><!--Spring配置文件的位置--><context-param><param-name>contextConfigLocation</param-name><param-value>applicationContext.xml</param-value></context-param>
</web-app>

4、上下文加载监听器ContextLoaderListener

负责 在上下文启动的时候去创建IOC容器,然后将其保存到application作用域

package com.wnx.myssm.mylistner;import com.wnx.myssm.myioc.BeanFactory;
import com.wnx.myssm.myioc.ClassPathXmlApplicationContext;import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;/*** 上下文加载监听器*/
@WebListener
public class ContextLoaderListener implements ServletContextListener {@Overridepublic void contextInitialized(ServletContextEvent sce) {//1.在上下文启动的时候去创建IOC容器,然后将其保存到application作用域ServletContext application = sce.getServletContext();String path = application.getInitParameter("contextConfigLocation");BeanFactory beanFactory = new ClassPathXmlApplicationContext(path);application.setAttribute("beanFactory",beanFactory);}@Overridepublic void contextDestroyed(ServletContextEvent sce) {}
}

5、前端控制器DispatcherServlet

package com.wnx.myssm.mysrpingmvc;import com.wnx.myssm.myioc.BeanFactory;
import com.wnx.myssm.utils.StringUtil;
import lombok.SneakyThrows;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;/*** 所有*.do的请求会进入到该Servlet!!!*/
@WebServlet("*.do")
public class DispatcherServlet extends ViewBaseServlet {private BeanFactory beanFactory ;public DispatcherServlet(){}public void init() throws ServletException {//1.Servlet在构建底层会调用Init()方法，集成ViewBaseServlet,会去调用ViewBaseServlet的Init()super.init();//2.从application作用域去获取IOC容器ServletContext application = getServletContext();Object beanFactoryObj = application.getAttribute("beanFactory");if(beanFactoryObj!=null){beanFactory = (BeanFactory)beanFactoryObj ;}else{throw new RuntimeException("IOC容器获取失败！");}}@SneakyThrows@Overrideprotected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1.获取Bean IDString servletPath = request.getServletPath();servletPath = servletPath.substring(1);int lastDotIndex = servletPath.lastIndexOf(".do") ;servletPath = servletPath.substring(0,lastDotIndex);//2.根据ID从容器中取出BeanObject controllerBeanObj = beanFactory.getBean(servletPath);//3.获取方法名String operate = request.getParameter("operate");if(StringUtil.isEmpty(operate)){ operate = "index" ; }Method[] methods = controllerBeanObj.getClass().getDeclaredMethods();for (Method method : methods) {//4.获取Handler方法对象if (operate.equals(method.getName())) {Parameter[] parameters = method.getParameters();Object[] parameterValues = new Object[parameters.length];//5.完成Controller方法参数绑定for (int i = 0; i < parameters.length; i++) {Parameter parameter = parameters[i];String parameterName = parameter.getName();if ("request".equals(parameterName)) {parameterValues[i] = request;} else if ("response".equals(parameterName)) {parameterValues[i] = response;} else if ("session".equals(parameterName)) {parameterValues[i] = request.getSession();} else {String parameterValue = request.getParameter(parameterName);String typeName = parameter.getType().getName();Object parameterObj = parameterValue;if (parameterObj != null) {if ("java.lang.Integer".equals(typeName)) {parameterObj = Integer.parseInt(parameterValue);}}if (parameterObj != null) {if ("java.lang.Long".equals(typeName)) {parameterObj = Long.parseLong(parameterValue);}}parameterValues[i] = parameterObj;}}//6.反射执行方法method.setAccessible(true);Object returnObj = method.invoke(controllerBeanObj, parameterValues);//7.视图处理String methodReturnStr = (String) returnObj;if (methodReturnStr.startsWith("redirect:")) {String redirectStr = methodReturnStr.substring("redirect:".length());response.sendRedirect(redirectStr);} else {super.processTemplate(methodReturnStr, request, response);}}}}
}

6、视图解析器ViewBaseServlet

package com.wnx.myssm.mysrpingmvc;import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.templatemode.TemplateMode;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;public class ViewBaseServlet extends HttpServlet {private TemplateEngine templateEngine;@Overridepublic void init() throws ServletException {// 1.获取ServletContext对象ServletContext servletContext = this.getServletContext();// 2.创建Thymeleaf解析器对象ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver(servletContext);// 3.给解析器对象设置参数templateResolver.setTemplateMode(TemplateMode.HTML);templateResolver.setPrefix(servletContext.getInitParameter("view-prefix"));templateResolver.setSuffix(servletContext.getInitParameter("view-suffix"));templateResolver.setCacheTTLMs(60000L);templateResolver.setCacheable(true);templateResolver.setCharacterEncoding("utf-8");// 4.创建模板引擎对象templateEngine = new TemplateEngine();// 5.给模板引擎对象设置模板解析器templateEngine.setTemplateResolver(templateResolver);}protected void processTemplate(String templateName, HttpServletRequest req, HttpServletResponse resp) throws IOException {// 1.设置响应体内容类型和字符集resp.setContentType("text/html;charset=UTF-8");// 2.创建WebContext对象WebContext webContext = new WebContext(req, resp, getServletContext());// 3.处理模板数据templateEngine.process(templateName, webContext, resp.getWriter());}
}

7、IOC容器上下文ClassPathXmlApplicationContext

• 抽象Bean工厂

package com.wnx.myssm.myioc;/*** Bean构建工厂*/
public interface BeanFactory {Object getBean(String id);
}

• 实现：ClassPathXmlApplicationContext

package com.wnx.myssm.myioc;import com.wnx.myssm.utils.StringUtil;
import lombok.SneakyThrows;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;public class ClassPathXmlApplicationContext implements BeanFactory {private Map<String,Object> beanMap = new HashMap<>();@SneakyThrowspublic ClassPathXmlApplicationContext(){this("applicationContext.xml");}@SneakyThrowspublic ClassPathXmlApplicationContext(String path){if(StringUtil.isEmpty(path)){ throw new RuntimeException("IOC容器的配置文件没有指定..."); }//1.根据Resource目录下applicationContext.xml，构造文档对象InputStream inputStream = getClass().getClassLoader().getResourceAsStream(path);DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder() ;Document document = documentBuilder.parse(inputStream);//2.扫描所有Bean标签NodeList beanNodeList = document.getElementsByTagName("bean");for(int i = 0 ; i<beanNodeList.getLength() ; i++){Node beanNode = beanNodeList.item(i);if(beanNode.getNodeType() == Node.ELEMENT_NODE){//1.根据Bean标签，由反射构造对象Element beanElement = (Element)beanNode ;String beanId =  beanElement.getAttribute("id");String className = beanElement.getAttribute("class");Class beanClass = Class.forName(className);Object beanObj = beanClass.newInstance() ;//2.存入Map容器beanMap.put(beanId , beanObj) ;}}//3.组装bean之间的依赖关系for(int i = 0 ; i<beanNodeList.getLength() ; i++){Node beanNode = beanNodeList.item(i);if(beanNode.getNodeType() == Node.ELEMENT_NODE) {Element beanElement = (Element) beanNode;String beanId = beanElement.getAttribute("id");NodeList beanChildNodeList = beanElement.getChildNodes();for (int j = 0; j < beanChildNodeList.getLength() ; j++) {//4.从容器中取出被依赖Bean 注入到被依赖Bean中Node beanChildNode = beanChildNodeList.item(j);if(beanChildNode.getNodeType()==Node.ELEMENT_NODE && "property".equals(beanChildNode.getNodeName())){Element propertyElement = (Element) beanChildNode;String propertyName = propertyElement.getAttribute("name");String propertyRef = propertyElement.getAttribute("ref");Object refObj = beanMap.get(propertyRef);Object beanObj = beanMap.get(beanId);Class beanClazz = beanObj.getClass();Field propertyField = beanClazz.getDeclaredField(propertyName);propertyField.setAccessible(true);propertyField.set(beanObj,refObj);}}}}}/*** 根据ID获取Bean* @param id ID* @return Bean*/@Overridepublic Object getBean(String id) {return beanMap.get(id);}
}

8、配置字符编码过滤器

package com.wnx.myssm.myfilter;import com.wnx.myssm.utils.StringUtil;import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;/*** 字符编码过滤器 过滤  *.do 的请求*/
@WebFilter(urlPatterns = {"*.do"},initParams = {@WebInitParam(name = "encoding",value = "UTF-8")})
public class CharacterEncodingFilter implements Filter {private String encoding = "UTF-8";@Overridepublic void init(FilterConfig filterConfig) throws ServletException {String encodingStr = filterConfig.getInitParameter("encoding");if(StringUtil.isNotEmpty(encodingStr)){encoding = encodingStr ;}}@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {((HttpServletRequest)servletRequest).setCharacterEncoding(encoding);filterChain.doFilter(servletRequest,servletResponse);}@Overridepublic void destroy() {}
}

9、持久层框架BaseMapper

package com.wnx.mall.tiny.mapper;import com.wnx.myssm.mymapper.ConnUtil;import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;public abstract class BaseMapper<T> {private final String DRIVER = "com.mysql.cj.jdbc.Driver";private final String URL = "jdbc:mysql://localhost:3306/mall?useUnicode=true&characterEncoding=utf-8&useSSL=false";private final String USER = "root";private final String PWD = "root" ;private Connection conn ;private PreparedStatement psmt ;private ResultSet rs ;private Class entityClass ;public BaseMapper(){//1.获取程序运行时，T实际指代的类型。Type genericType = getClass().getGenericSuperclass();Type[] actualTypeArguments = ((ParameterizedType) genericType).getActualTypeArguments();Type actualType = actualTypeArguments[0];// 2.构造该T的类对象try {entityClass = Class.forName(actualType.getTypeName());} catch (ClassNotFoundException e) {e.printStackTrace();}}/*** 获取数据库连接* @return 一个数据库连接*/private Connection getConn(){return ConnUtil.getConn();}/*** 释放数据库相关资源* @param rs 结果集对象* @param psmt 预编译陈述对象* @param conn 数据库连接*/private void close(ResultSet rs, PreparedStatement psmt, Connection conn){try {if (rs != null) {rs.close();}if(psmt!=null){psmt.close();}if(conn!=null && !conn.isClosed()){conn.close();}} catch (SQLException e) {e.printStackTrace();}}/**** 给预处理陈述对象的占位符?设置参数* @param psmt 预处理陈述对象* @param params 参数* @throws SQLException SQL异常*/private void setParams(PreparedStatement psmt , Object... params) throws SQLException {if(params!=null && params.length>0){for (int i = 0; i < params.length; i++) {psmt.setObject(i+1,params[i]);}}}/**** 执行数据库更新操作* @param sql 数据库操作SQL* @param params 更新参数* @return 受到影响的行数*/protected int executeUpdate(String sql , Object... params){boolean insertFlag = false ;try {conn = getConn();psmt = conn.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);setParams(psmt,params);int count = psmt.executeUpdate() ;rs = psmt.getGeneratedKeys();if(rs.next()){return ((Long)rs.getLong(1)).intValue();}return count ;} catch (SQLException e) {e.printStackTrace();}finally {close(rs,psmt,conn);}return 0;}/*** 通过反射技术给obj对象的property属性赋propertyValue值* @param obj 对象model* @param property model字段* @param propertyValue model值*/private void setValue(Object obj ,  String property , Object propertyValue){//1.获取对象的类Class clazz = obj.getClass();try {//2.根据成员变量名获取成员变量Field field = clazz.getDeclaredField(property);//3.反射赋值if(field!=null){field.setAccessible(true);field.set(obj,propertyValue);}} catch (Exception e) {e.printStackTrace();}}/*** 执行复杂查询，返回例如统计结果* @param sql 数据库操作SQL* @param params 更新参数* @return 对象数组*/protected Object[] executeComplexQuery(String sql , Object... params){try {//1.执行查询conn = getConn() ;psmt = conn.prepareStatement(sql);setParams(psmt,params);rs = psmt.executeQuery();//2.构造列容器ResultSetMetaData rsmd = rs.getMetaData();int columnCount = rsmd.getColumnCount();Object[] columnValueArr = new Object[columnCount];//3.查询结果放入列容器if(rs.next()){for(int i = 0 ; i<columnCount;i++){Object columnValue = rs.getObject(i+1);columnValueArr[i]=columnValue;}//4.返回列容器return columnValueArr ;}} catch (SQLException e) {e.printStackTrace();} finally {close(rs,psmt,conn);}return null ;}/*** 执行查询，返回单个实体对象* @param sql 数据库操作SQL* @param params 查询参数* @return 实体Model*/protected T load(String sql , Object... params){try {//1.查询操作conn = getConn() ;psmt = conn.prepareStatement(sql);setParams(psmt,params);rs = psmt.executeQuery();//2.对象赋值ResultSetMetaData rsmd = rs.getMetaData();int columnCount = rsmd.getColumnCount();if(rs.next()){T entity = (T)entityClass.newInstance();for(int i = 0 ; i<columnCount;i++){String columnName = rsmd.getColumnName(i+1);//3.驼峰命名的转化while (columnName.contains("_")) {int index = columnName.indexOf("_");String target = columnName.substring(index + 1, index + 2);columnName = columnName.replace(("_" + target), target.toUpperCase());}Object columnValue = rs.getObject(i+1);setValue(entity,columnName,columnValue);}//3.返回对象return entity ;}} catch (Exception e) {e.printStackTrace();} finally {close(rs,psmt,conn);}return null ;}/**** 执行查询，返回List* @param sql  数据库操作SQL* @param params 查询参数* @return 实体集合List*/protected List<T> executeQuery(String sql , Object... params){List<T> list = new ArrayList<>();try {//1.执行查询conn = getConn() ;psmt = conn.prepareStatement(sql);setParams(psmt,params);rs = psmt.executeQuery();//2.对象赋值ResultSetMetaData rsmd = rs.getMetaData();int columnCount = rsmd.getColumnCount();while(rs.next()){T entity = (T)entityClass.newInstance();for(int i = 0 ; i<columnCount;i++){String columnName = rsmd.getColumnName(i+1);//3.驼峰命名的转化while (columnName.contains("_")) {int index = columnName.indexOf("_");String target = columnName.substring(index + 1, index + 2);columnName = columnName.replace(("_" + target), target.toUpperCase());}Object columnValue = rs.getObject(i+1);setValue(entity,columnName,columnValue);}//4.添加到集合list.add(entity);}} catch (Exception e) {e.printStackTrace();} finally {close(rs,psmt,conn);}//5.返回集合return list ;}}

10、事务控制TransactionManager

	package com.wnx.myssm.mytransaction;import com.wnx.myssm.mymapper.ConnUtil;import java.sql.Connection;
import java.sql.SQLException;public class TransactionManager {//开启事务public static void beginTrans() throws SQLException {ConnUtil.getConn().setAutoCommit(false);}//提交事务public static void commit() throws SQLException {Connection conn = ConnUtil.getConn();conn.commit();ConnUtil.closeConn();}//回滚事务public static void rollback() throws SQLException {Connection conn = ConnUtil.getConn();conn.rollback();ConnUtil.closeConn();}
}

11、线程知识

使用一个连接Connection才能说事务，一次请求对应一次线程。重写获取数据库连接类

• ConnUtil

package com.wnx.myssm.mymapper;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;public class ConnUtil {private static ThreadLocal<Connection> threadLocal = new ThreadLocal<>();private static final String DRIVER = "com.mysql.cj.jdbc.Driver";private static final String URL = "jdbc:mysql://localhost:3306/javaweb?useUnicode=true&characterEncoding=utf-8&useSSL=false&allowPublicKeyRetrieval=true";private static final String USER = "root";private static final String PWD = "root";/*** 创建数据库连接* @return 返回数据库连接*/private static Connection createConn() {try {Class.forName(DRIVER);return DriverManager.getConnection(URL, USER, PWD);} catch (ClassNotFoundException | SQLException e) {e.printStackTrace();}return null;}/*** 获取数据库连接* @return 数据库连接*/public static Connection getConn() {//1.有则用本地线程的连接，没有就创建一个。Connection conn = threadLocal.get();if (conn == null) {conn = createConn();threadLocal.set(conn);}return threadLocal.get();}/*** 关闭数据库连接* @throws SQLException SQL异常*/public static void closeConn() throws SQLException {Connection conn = threadLocal.get();if(conn==null){return ;}if(!conn.isClosed()){conn.close();threadLocal.set(null);}}}

一但出现异常，让当前数据库连接马上回滚。

• OpenSessionInViewFilter

package com.wnx.myssm.myfilter;import com.wnx.myssm.mytransaction.TransactionManager;import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;
import java.sql.SQLException;@WebFilter("*.do")
public class OpenSessionInViewFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {try{TransactionManager.beginTrans();System.out.println("开启事务....");filterChain.doFilter(servletRequest, servletResponse);TransactionManager.commit();System.out.println("提交事务...");}catch (Exception e){e.printStackTrace();try {TransactionManager.rollback();System.out.println("回滚事务....");} catch (SQLException ex) {ex.printStackTrace();}}}@Overridepublic void destroy() {}
}

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