Roo是一种 Spring 开发的辅助工具，使用命令行操作来生成自动化项目，操作非常类似于rails
我这里使用spring tool suit来开发一个demo项目
首先新建个spring template project，然后选择template类型为Roo Wep App (based on Roo 1.0.0.RC1)
这样，便会通过roo的命令自动生成一个标准的maven web项目，里面含有最基本的Spring 配置
建好项目后，我们可以在project上运行roo shell。 通过hint命令，我们可以很快的了解各种操作提示
首先，设置数据库
Roo shell代码
1. install jpa -provider HIBERNATE -database MYSQL
roo会帮你在配置文件applicationContext.xml中配置好了相应的数据源配置，并且在 pom.xml中已经添加jpa和数据库驱动等相关的依赖。
然后新建一个domain
Roo shell代码
1. new persistent class jpa -name ~.domain.Employee -testAutomatically
这时roo会帮我们生成Employee类，这时Employee类还没有任何字段，我们可以通过roo shell往里面加入一些字段
Roo shell代码
1. add field string -fieldName name -notNull -sizeMax 200
2. add field date jpa -fieldName birth -type java.util.Date
3. ......
最终生成的Employee如下：
Java代码
1. @Entity
2. @RooEntity
3. @RooJavaBean
4. @RooToString
5. public class Employee {
6.
7. @NotNull
8. @Size(max = 200)
9. private String name;
10.
11. @Temporal(TemporalType.TIMESTAMP)
12. private Date birth;
13. }
你会发现，怎么没有get set呢？我们反编译看下编译后的class代码
。
经过反编译生成的class发现，通过domain类上面的roo注释，自动在类编译时加入get set，甚至我们发现了findAllEmployees，persist，remove，哈，这不是我们梦寐以求的充血模型吗？
原来，roo在为我们创建domain的时候自动为同一个domain创建了4个aspect(.aj files)，并在编译期动态为domain切入代码.
4个aspect分别是：
domainName_Roo_Configurable.aj(配置)
domainName_Roo_Entity.aj(加入orm持久)
domainName_Roo_JavaBean.aj(为字段生成get set)
domainName_Roo_ToString.aj(重写toString)
可见，使用roo我们彻底摆脱了在daomain里对各个属性写get set，并且使domain摇身一变为充血。
下一步，就是建Controller了，同样是一条语句
Roo shell代码
1. new controller automatic -formBackingObject ~.domain.Employee -name ~.web.CommentController 你会发现，EmployeeController，spring mvc的配置以及curd的jsp页面全部生成了
EmployeeController代码如下：
Java代码
1. @RooWebScaffold(automaticallyMaintainView = true, formBackingObject = Employee.class)
2. @RequestMapping("/employee/**")
3. @Controller
4. public class EmployeeController {
5. }
在这里出现了一行@RooWebScaffold注解，做过rails的人会想，这不是rails里面的scaffold吗？没错，通过@RooWebScaffold注解，EmployeeController自动获得了curd的所有功能。
同样是生成controllerName_Roo_Controller.aj在编译期织入代码
我们来看看生成的EmployeeController_Roo_Controller.aj:
package com.javaeye.web;
privileged aspect EmployeeController_Roo_Controller {
@org.springframework.web.bind.annotation.RequestMapping(value = "/employee", method = org.springframework.web.bind.annotation.RequestMethod.POST)
public java.lang.String EmployeeController.create(@org.springframework.web.bind.annotation.ModelAttribute("employee") com.javaeye.domain.Employee employee, org.springframework.validation.BindingResult result) {
if (employee == null) throw new IllegalArgumentException("A employee is required");
for(javax.validation.ConstraintViolation<com.javaeye.domain.Employee> constraint : javax.validation.Validation.buildDefaultValidatorFactory().getValidator().validate(employee)) {
result.rejectValue(constraint.getPropertyPath(), null, constraint.getMessage());
}
if (result.hasErrors()) {
return "employee/create";
}
employee.persist();
return "redirect:/employee/" + employee.getId();
}
@org.springframework.web.bind.annotation.RequestMapping(value = "/employee/form", method = org.springframework.web.bind.annotation.RequestMethod.GET)
public java.lang.String EmployeeController.createForm(org.springframework.ui.ModelMap modelMap) {
modelMap.addAttribute("employee", new com.javaeye.domain.Employee());
return "employee/create";
}
@org.springframework.web.bind.annotation.RequestMapping(value = "/employee/{id}", method = org.springframework.web.bind.annotation.RequestMethod.GET)
public java.lang.String EmployeeController.show(@org.springframework.web.bind.annotation.PathVariable("id") java.lang.Long id, org.springframework.ui.ModelMap modelMap) {
if (id == null) throw new IllegalArgumentException("An Identifier is required");
modelMap.addAttribute("employee", com.javaeye.domain.Employee.findEmployee(id));
return "employee/show";
}
@org.springframework.web.bind.annotation.RequestMapping(value = "/employee", method = org.springframework.web.bind.annotation.RequestMethod.GET)
public java.lang.String EmployeeController.list(org.springframework.ui.ModelMap modelMap) {
modelMap.addAttribute("employees", com.javaeye.domain.Employee.findAllEmployees());
return "employee/list";
}
@org.springframework.web.bind.annotation.RequestMapping(method = org.springframework.web.bind.annotation.RequestMethod.PUT)
public java.lang.String EmployeeController.update(@org.springframework.web.bind.annotation.ModelAttribute("employee") com.javaeye.domain.Employee employee, org.springframework.validation.BindingResult result) {
if (employee == null) throw new IllegalArgumentException("A employee is required");
for(javax.validation.ConstraintViolation<com.javaeye.domain.Employee> constraint : javax.validation.Validation.buildDefaultValidatorFactory().getValidator().validate(employee)) {
result.rejectValue(constraint.getPropertyPath(), null, constraint.getMessage());
}
if (result.hasErrors()) {
return "employee/update";
}
employee.merge();
return "redirect:/employee/" + employee.getId();
}
@org.springframework.web.bind.annotation.RequestMapping(value = "/employee/{id}/form", method = org.springframework.web.bind.annotation.RequestMethod.GET)
public java.lang.String EmployeeController.updateForm(@org.springframework.web.bind.annotation.PathVariable("id") java.lang.Long id, org.springframework.ui.ModelMap modelMap) {
if (id == null) throw new IllegalArgumentException("An Identifier is required");
modelMap.addAttribute("employee", com.javaeye.domain.Employee.findEmployee(id));
return "employee/update";
}
@org.springframework.web.bind.annotation.RequestMapping(value = "/employee/{id}", method = org.springframework.web.bind.annotation.RequestMethod.DELETE)
public java.lang.String EmployeeController.delete(@org.springframework.web.bind.annotation.PathVariable("id") java.lang.Long id) {
if (id == null) throw new IllegalArgumentException("An Identifier is required");
com.javaeye.domain.Employee.findEmployee(id).remove();
return "redirect:/employee";
}
@org.springframework.web.bind.annotation.InitBinder
public void EmployeeController.initBinder(org.springframework.web.bind.WebDataBinder binder) {
binder.registerCustomEditor(java.util.Date.class, new org.springframework.beans.propertyeditors.CustomDateEditor(new java.text.SimpleDateFormat("yyyy-M-d"), false));
}
}
好了，就这么简单，一个domain，一个Controller，我们就可以发布到tomcat中运行了。
不到5分钟，我们就可以生成了一个可运行的项目，是不是很有ror式的感觉啊？赶快来试试吧
