上篇主要介绍了ssm框架整合的配置文件，接下来我们介绍具体的应用实例。应用项目借鉴了该博主的案例，但其项目时间比较早，我们采用idea并且运用当下常用的技术，制作一个简单的图书预约系统。
项目已上传至GitHub：GitHub - caiyucheng00/ssm
逐步学习SSM框架整合：Spring + SpringMVC + MyBatis（上）
目录
1.数据库的构建
2.创建枚举类、异常类、过程类
3.service层的创建
4.controller层的创建
1.数据库的构建
主要有两张表，book表如下：三个字段是id，name和数量
appointment表如下：三个字段是学生id，图书id和预约时间
并且采用上篇提到的mybatis逆向工程创建bean对象和对应的mapper接口和xml文件。
测试一下mapper类：
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath*:spring-config.xml"})
public class MapperTest {
@Autowired
BookMapper bookMapper;
@Test
public void testQuery(){
List bookList = bookMapper.selectByExample(null);
for(Book book:bookList){
System.out.println(book);
}
}
}
结果如下，说明配置文件都正确，无异常：
2.创建枚举类、异常类、过程类
枚举类代表了图书的预约状态，如下：
public enum AppointStateEnum {
SUCCESS(1,"预约成功"),NO_NUMBER(0,"库存不足"),REPEAT_APPOINT(-1,"重复预约"),INNER_ERROR(-2,"系统异常");
private int state;
private String info;
AppointStateEnum(int state, String info) {
this.state = state;
this.info = info;
}
public int getState() {
return state;
}
public String getInfo() {
return info;
}
}
异常类比如预约图书时出现了没有库存的异常：
public class NoNumberException extends RuntimeException{
public NoNumberException(String message) {
super(message);
}
public NoNumberException(String message, Throwable cause) {
super(message, cause);
}
}
以及存储执行预约操作的返回结果，保存了图书编号，图书状态和预约信息：
public class AppointExecution {
private Integer bookId;
private int state;
private String info;
private Appointment appointment;
public AppointExecution() {
}
// 预约成功
public AppointExecution(Integer bookId, AppointStateEnum stateEnum, Appointment appointment) {
this.bookId = bookId;
this.state = stateEnum.getState();
this.info = stateEnum.getInfo();
this.appointment = appointment;
}
public Integer getBookId() {
return bookId;
}
public void setBookId(Integer bookId) {
this.bookId = bookId;
}
public int getState() {
return state;
}
public void setState(int state) {
this.state = state;
}
public String getInfo() {
return info;
}
public void setInfo(String info) {
this.info = info;
}
public Appointment getAppointment() {
return appointment;
}
public void setAppointment(Appointment appointment) {
this.appointment = appointment;
}
@Override
public String toString() {
return "AppointExecution{" +
"bookId=" + bookId +
", state=" + state +
", info='" + info + ''' +
", appointment=" + appointment +
'}';
}
}
3.service层的创建
service层业务逻辑主要有两个接口与两个实现类。对于book表来说实现了查询功能和预约功能，代码如下：
@Service
public class BookServiceImpl implements BookService {
@Autowired
private BookMapper bookMapper;
@Autowired
private AppointmentMapper appointmentMapper;
@Override
public Book getById(Integer bookId) {
return bookMapper.selectByPrimaryKey(bookId);
}
@Override
public List getAll() {
return bookMapper.selectByExample(null);
}
@Override
@Transactional
public AppointExecution appoint(Integer bookId, long studentId) {
try {
// 减少库存
Book book = bookMapper.selectByPrimaryKey(bookId);
Integer bookCount = book.getBookCount();
if (bookCount <= 0) {
throw new NoNumberException("库存不足");
} else {
book.setBookCount(bookCount - 1);
bookMapper.updateByPrimaryKeySelective(book);
appointmentMapper.insert(new Appointment(studentId, bookId, new Date(new java.util.Date().getTime())));
AppointmentExample appointmentExample = new AppointmentExample();
appointmentExample.createCriteria().andBookIdEqualTo(bookId).andStudentIdEqualTo(studentId);
List appointmentList = appointmentMapper.selectByExample(appointmentExample);
return new AppointExecution(bookId, AppointStateEnum.SUCCESS, appointmentList.get(0));
}
} catch (NoNumberException e) {
e.getMessage();
} catch (Exception e) {
throw new AppointException("other error:" + e.getMessage());
}
return null;
}
}
appointment表目前只做一个查询功能：
@Service
public class AppointServiceImpl implements AppointService {
@Autowired
private AppointmentMapper appointmentMapper;
@Override
public List getAll() {
return appointmentMapper.selectByExample(null);
}
}
对service层进行测试：
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath*:spring-config.xml"})
public class ServiceTest {
@Autowired
private BookService bookService;
@Test
public void test(){
AppointExecution appointExecution = bookService.appoint(5, 11118403L);
System.out.println(appointExecution);
}
}
结果如下：
4.controller层的创建
最后一步来到了controller层，也就是和前端的交互，用到了@RequestMapping注解。
已/book/..为例，查找book与添加预约信息用到了RESTFul风格的url，GET方法是查找，PUT方法是新建信息。
@RequestMapping(value = "/list",method = RequestMethod.GET)
private String list(Model model){
List bookList = bookService.getAll();
model.addAttribute("bookList",bookList);
return "bookList";
}
@RequestMapping(value = "/list",method = RequestMethod.POST)
private String add(@Param("studentId") String studentId,@Param("bookId") String bookId){
int bookID = Integer.parseInt(bookId);
long studentID = Long.parseLong(studentId);
bookService.appoint(bookID,studentID);
return "redirect:/book/list";
}
简单的bookList.html界面如下：
添加预定后界面重定向回bookList.html
可以看到book_id=7的图书数量减一
预约信息均可以在appointmentList.html看到
OK，SSM框架的搭建与应用实例到这里就结束了。其实还是比较麻烦的，所以下一步就要进行springboot的学习，在框架上再封装一次框架。
