用SSM实现简易的发票管理系统

SSM（Spring、SpringMVC、MyBatis）是一种流行的Java开发框架，用于构建企业级应用程序。在实现简易的发票管理系统时，我们可以使用SSM框架来简化开发过程。以下是一个简单的示例：

1. 首先，创建一个Spring Boot项目，并添加必要的依赖项。在pom.xml文件中添加以下依赖：

```xml

org.springframework.boot

spring-boot-starter-web

org.mybatis.spring.boot

mybatis-spring-boot-starter

2.1.4

```

2. 创建实体类（Entity）：

```java

public class Invoice {

private Long id;

private String customerName;

private Double amount;

private Date issuedDate;

// getter和setter方法

}

```

3. 创建Mapper接口（Mapper）：

```java

import org.apache.ibatis.annotations.Mapper;

import org.apache.ibatis.annotations.Select;

@Mapper

public interface InvoiceMapper {

@Select("SELECT * FROM invoice WHERE customer_name = #{customerName}")

Invoice selectByCustomerName(String customerName);

}

```

4. 创建Service接口（Service）：

```java

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

@Service

public class InvoiceService {

@Autowired

private InvoiceMapper invoiceMapper;

public Invoice getInvoiceByCustomerName(String customerName) {

return invoiceMapper.selectByCustomerName(customerName);

}

}

```

5. 创建Controller类（Controller）：

```java

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.bind.annotation.RestController;

@RestController

public class InvoiceController {

@Autowired

private InvoiceService invoiceService;

@GetMapping("/invoice/{customerName}")

public Invoice getInvoiceByCustomerName(@PathVariable String customerName) {

Invoice invoice = invoiceService.getInvoiceByCustomerName(customerName);

return invoice;

}

}

```

6. 运行项目，访问`http://localhost:8080/invoice/{customerName}`，例如`http://localhost:8080/invoice/张三`，将返回与张三相关的发票信息。