在前面的快速入门教程中，我们利用5分钟构建了一个非常简单的RESTful Webservice，现在我们来利用Spring Boot来构建一个复杂一点的RestFul API。

关于RESTful API如何设计，大家可以自行去阮一峰的博客学习一下。话说阮老师真是一个全才，感觉他都懂，程序猿楷模啊！

我们来设计一个Book的RESTful API，如下所示：

Book的实体类定义如下：

public class Book {

    private Long bookId;
    private String title;
    private String author;

    //getter/setter方法省略
}

针对Book资源操作的RESTful接口实现如下：

@RestController
@RequestMapping(value="/books")
public class BookController {

    // 创建线程安全的Map
    static Map<Long, Book> books = Collections.synchronizedMap(new HashMap<Long, Book>());

    @RequestMapping(value="/", method= RequestMethod.GET)
    public List<Book> getUserList() {
        // 处理"/books/"的GET请求，用来获取图书列表
        // 还可以通过@RequestParam传递参数来进行查询条件或者翻页信息的传递
        List<Book> r = new ArrayList<Book>(books.values());
        return r;
    }

    @RequestMapping(value="/", method=RequestMethod.POST,produces = "application/json")
    public String createBook(@RequestBody Book book) {
        // 处理"/books/"的POST请求，用来创建User
        // 除了@ModelAttribute绑定参数之外，还可以通过@RequestParam从页面中传递参数
        books.put(book.getBookId(), book);
        return "success";
    }

    @RequestMapping(value="/{bookId}", method=RequestMethod.GET)
    public Book getBook(@PathVariable Long bookId) {
        // 处理"/books/{id}"的GET请求，用来获取url中id值的Book信息
        // url中的id可通过@PathVariable绑定到函数的参数中
        return books.get(bookId);
    }

    @RequestMapping(value="/{bookId}", method=RequestMethod.PUT)
    public String putBook(@PathVariable Long bookId, @RequestBody Book book) {
        // 处理"/books/{bookId}"的PUT请求，用来更新Book信息
        Book b = books.get(bookId);
        b.setTitile(book.getTitile());
        b.setAuthor(book.getAuthor());
        books.put(bookId, b);
        return "success";
    }

    @RequestMapping(value="/{bookId}", method=RequestMethod.DELETE)
    public String deleteBook(@PathVariable Long bookId) {
        // 处理"/books/{bookId}"的DELETE请求，用来删除Book
        books.remove(bookId);
        return "success";
    }
}

单元测试

之前我们在入门教程中使用了Postman来进行测试，现在我们使用Spring自家的MockMvc框架来写单元测试，MockMvc的使用很简单，更详细的用法大家可以自行Google或百度。

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = MockServletContext.class)
@WebAppConfiguration
public class TestBookController {

    private MockMvc mvc;

    private RequestBuilder request = null;


    @Before
    public void setUp() throws Exception {
        mvc = MockMvcBuilders.standaloneSetup(new BookController()).build();
        request = null;
    }

    public void testGet() throws Exception{
        request = get("/books/");
        mvc.perform(request)
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("[]")));
    }

    public void testPost() throws Exception{
        Book book = new Book();
        book.setBookId(Long.parseLong("1"));
        book.setTitile("Spring Boot Tutorial");
        book.setAuthor("bluecoffee");
        ObjectMapper objectMapper = new ObjectMapper();
        String jsonBook = objectMapper.writeValueAsString(book);

        request = post("/books/")
                .contentType(MediaType.APPLICATION_JSON)
                .content(jsonBook.getBytes());

        mvc.perform(request)
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("success")));

        String respStr = mvc.perform(get("/books/"))
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("[" + jsonBook + "]")))
                .andReturn().getResponse().getContentAsString();
        System.out.println("testPost.resp:"+respStr);
    }

    public void testPut() throws Exception{
        Book book = new Book();
        book.setBookId(Long.parseLong("1"));
        book.setTitile("Spring Boot学习教程");
        book.setAuthor("Alex Qian");
        ObjectMapper objectMapper = new ObjectMapper();
        String jsonBook = objectMapper.writeValueAsString(book);

        request = put("/books/" + book.getBookId())
                .contentType(MediaType.APPLICATION_JSON)
                .content(jsonBook.getBytes());

        mvc.perform(request)
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("success")));

        String respStr = mvc.perform(get("/books/"+book.getBookId()))
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo(jsonBook)))
                .andReturn().getResponse().getContentAsString();
        System.out.println("testPut.resp:"+respStr);
    }

    public void testDelete() throws Exception{
        request = delete("/books/1");
        mvc.perform(request)
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("success")));

        String respStr = mvc.perform(get("/books/"))
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("[]")))
                .andReturn().getResponse().getContentAsString();
        System.out.println("testDelete.resp:"+respStr);

    }

    @Test
    public void testSuite() throws Exception{
        this.testGet();//获取一本书籍
        this.testPost();//创建一本书籍
        this.testPut();//更新一本书籍
        this.testDelete();//删除一本书籍
    }
}

小结

在这次教程里面，我们仅引入Spring Boot的web模块，并且没有引入任何配置文件，就构建了一个较完整的RESTful API，文中还简要介绍了@PathVariable,@RequestBody,@RequestParam等参数绑定注解的用法，更多的用法大家可以自行去网上查询资料。

完整代码戳这里: Chapter 3-1-1 - 构建复杂RESTful API及单元测试