jfinal框架教程-学习笔记(二)
上一节介绍了jfinal框架的简单搭建,这节通过一个小例子了解jfinal的结构和特点
先上图
1、建数据库(我用的是oracle数据库,其他的相对也差不多)
-- Create table create table CLASSES ( classesid NUMBER not null, classesname VARCHAR2(20), classesaddress VARCHAR2(50) ); -- Create table create table STUDENT ( studentid NUMBER not null, studentname VARCHAR2(10), studentage NUMBER, studentsex VARCHAR2(2), classesid NUMBER ); alter table STUDENT add constraint FK_CLASSESID foreign key (CLASSESID) references CLASSES (CLASSESID);
新建项目,我用的myeclipse,先把jar包导入
2、实体类
Classes.java
package com.demo.model; import com.jfinal.plugin.activerecord.Model; public class Classes extends Model<Classes> { public static final Classes dao = new Classes(); }
Student.java
package com.demo.model; import com.jfinal.plugin.activerecord.Model; public class Student extends Model<Student> { public static final Student dao = new Student(); public Classes getClasses() { return Classes.dao.findById(get("classesid")); } }
什么这是实体类?没错!!~ ActiveRecord 是 jfinal 最核心的组成部分之一,通过 ActiveRecord 来操作数据库,将极大地减少代码量,极大地提升开发效率,配置在后面,我这里用的是Model,Model 是 ActiveRecord 中最重要的组件之一,它充当 MVC 模式中的 Model部分。
以上代码中的 User 通过继承 Model,便立即拥有的众多方便的操作数据库的方法。在 User 中声明的 dao 静态对象是为了方便查询操作而定义的,该对象并不是必须的。 基于ActiveRecord 的 Model 无需定义属性, 无需定义 getter、 setter方法,无需 XML 配置,无需 Annotation 配置,极大降低了代码量。Model常见方法见官方API。
JFinal还有 独创 Db + Record 模式,Db 类及其配套的 Record 类, 提供了在 Model 类之外更为丰富的数据库操作功能。使用 Db 与 Record 类时,无需对数据库表进行映射,Record 相当于一个通用的 Model。Db常见方法见官方API。
3、DemoConfig.java
package com.demo.config; import com.demo.controller.ClassesController; import com.demo.controller.StudentController; import com.demo.model.Classes; import com.demo.model.Student; import com.jfinal.config.Constants; import com.jfinal.config.Handlers; import com.jfinal.config.Interceptors; import com.jfinal.config.JFinalConfig; import com.jfinal.config.Plugins; import com.jfinal.config.Routes; import com.jfinal.plugin.activerecord.ActiveRecordPlugin; import com.jfinal.plugin.activerecord.CaseInsensitiveContainerFactory; import com.jfinal.plugin.activerecord.dialect.OracleDialect; import com.jfinal.plugin.c3p0.C3p0Plugin; public class DemoConfig extends JFinalConfig { @Override public void configConstant(Constants me) { } @Override public void configHandler(Handlers me) { // TODO Auto-generated method stub } @Override public void configInterceptor(Interceptors me) { // TODO Auto-generated method stub } @Override public void configPlugin(Plugins me) { C3p0Plugin cp = new C3p0Plugin("jdbc:oracle:thin:@localhost:1521:orcl", "test", "test"); // 配置Oracle驱动 cp.setDriverClass("oracle.jdbc.driver.OracleDriver"); me.add(cp); ActiveRecordPlugin arp = new ActiveRecordPlugin(cp); me.add(arp); // 配置Oracle方言 arp.setDialect(new OracleDialect()); // 配置属性名(字段名)大小写不敏感容器工厂 arp.setContainerFactory(new CaseInsensitiveContainerFactory()); arp.addMapping("student", "studentid", Student.class); arp.addMapping("classes", "classesid", Classes.class); } @Override public void configRoute(Routes me) { me.add("/", StudentController.class); me.add("/student", StudentController.class); me.add("/classes", ClassesController.class); } }
我这里是oracle数据库的配置,oracle有些特别的地方,如表列名会自动转成大写,配置个免大小写的工厂,方便开发等。这里要注意url,驱动,方言,在给个mysql数据库的配置对比下
public class DemoConfig extends JFinalConfig { public void configPlugin(Plugins me) { C3p0Plugin cp = new C3p0Plugin("jdbc:mysql://localhost/db_name", "userName", "password"); me.add(cp); ActiveRecordPlugin arp = new ActiveRecordPlugin(cp); me.add(arp); arp.addMapping("user", User.class); arp.addMapping("article", "article_id", Article.class); } }
4、StudentController.java
package com.demo.controller; import java.util.List; import com.demo.interceptor.StudentInterceptor; import com.demo.model.Student; import com.demo.validator.StudentValidator; import com.jfinal.aop.Before; import com.jfinal.core.Controller; public class StudentController extends Controller { @Before(StudentInterceptor.class) public void index() { List<Student> list = Student.dao.find("select * from student"); setAttr("studentList", list); render("/index.html"); } public void add() { render("/add.html"); } public void delete() { // 获取表单域名为studentID的值 // Student.dao.deleteById(getPara("studentID")); // 获取url请求中第一个值 Student.dao.deleteById(getParaToInt()); forwardAction("/student"); } public void update() { Student student = getModel(Student.class); student.update(); forwardAction("/student"); } public void get() { Student student = Student.dao.findById(getParaToInt()); setAttr("student", student); render("/index2.html"); } @Before(StudentValidator.class) public void save() { Student student = getModel(Student.class); student.set("studentid", "mysequence.nextval").save(); forwardAction("/student"); } }
获取studentid那里有多种方法,这个要和前台传参写法一致,Controller 提供了 getPara 系列方法,官网api里很详细
jfinal用的是原生态sql语句,简单,方便,setAttr("studentList", list);把结果集放到request范围里,
jfinal也有直接获取表单里分装成对象的方法 getModel(Student.class);就是,和struts2一样,表单name对应上就可以了,非常方便
添加那里对于oracle用序列维护studentid student.set("studentid", "mysequence.nextval").save(); jfinal有多种返回方式,也可以返回json数据,render 系列方法,官网api里很详细
5、interceptor和validator(可以不加)
StudentInterceptor.java
package com.demo.interceptor; import com.jfinal.aop.Interceptor; import com.jfinal.core.ActionInvocation; public class StudentInterceptor implements Interceptor { public void intercept(ActionInvocation ai) { System.out.println("Before action invoking"); ai.invoke(); System.out.println("After action invoking"); } }
StudentValidator.java
package com.demo.validator; import com.jfinal.core.Controller; import com.jfinal.validate.Validator; public class StudentValidator extends Validator { //在校验失败时才会调用 @Override protected void handleError(Controller controller) { controller.keepPara("student.studentname");//将提交的值再传回页面以便保持原先输入的值 controller.render("/add.html"); } @Override protected void validate(Controller controller) { //验证表单域name,返回信息key,返回信息value validateRequiredString("student.studentname", "studentnameMsg", "请输入学生名称!"); } }
6、页面
我这里用的是FreeMarker模板引擎
index.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>index.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> </head> <body> <a href="/student/add">添加</a> <table border="1"> <tr> <td> 姓名 </td> <td> 年龄 </td> <td> 性别 </td> <td> 班级 </td> <td> 操作 </td> </tr> <#list studentList as student> <tr> <td> ${student.studentname} </td> <td> ${student.studentage} </td> <td> ${student.studentsex} </td> <td> ${student.getClasses().classesname} </td> <td> <a href="/student/delete/${student.studentid}">删除</a> <a href="/student/get/${student.studentid}">修改</a> </td> </tr> </#list> </table> </body> </html>
index2.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>index2.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> </head> <body> <form action="/student/update" method="post"> <input type="text" name="student.studentid" value="${student.studentid}"/> 姓名: <input type="text" name="student.studentname" value="${student.studentname}"/> <br /> 年龄: <input type="text" name="student.studentage" value="${student.studentage}"/> <br /> 性别: <input type="text" name="student.studentsex" value="${student.studentsex}"/> <br /> 班级: <input type="text" name="student.classesid" value="${student.classesid}" /> <br /> <input type="submit" value="保存" /> </form> </body> </html>
add.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>add.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> </head> <body> <form action="/student/save" method="post"> 姓名: <input type="text" name="student.studentname" />${studentnameMsg!}${studentnameLMsg!} <br /> 年龄: <input type="text" name="student.studentage" /> <br /> 性别: <input type="text" name="student.studentsex" /> <br /> 班级: <input type="text" name="student.classesid" /> <br /> <input type="submit" value="保存" /> </form> </body> </html>
完成! 浏览器输入http://localhost/