@Data
public class Book {
        private Integer id;
        private String type;
        private String name;
        private String description; 
}

spring:
  datasource:
    druid:
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/ssm_db?servierTimezone=UTC
      username: root
      password: root

mybatis-plus:
  global-config:
    db-config:
      table-prefix: tbl_
      id-type: auto

@Mapper
public interface BookDao extends BaseMapper<Book> {  
}

@SpringBootTest
public class BookDaoTestCase {
    @Autowired
    private BookDao bookDao;

    @Test
    void testSave(){
        Book book = new Book();
        book.setName("測(cè)試數(shù)據(jù)");
        book.setType("測(cè)試類(lèi)型");
        bookDao.insert(book);
    }
    @Test
    void testGetById() {
        System.out.println(bookDao.selectById(1));
    }
}

mybatis-plus:
  global-config:
    db-config:
      table-prefix: tbl_
      id-type: auto
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

// MyBatisPlus攔截器
@Configuration
public class MPConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        //1.定義Mp攔截
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        //2.添加具體的攔截器
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor());
        return interceptor;
    }
}

// 條件查詢(xún)功能
@Test
void testGetByCondition(){
    IPage page = new Page(1,10);
    LambdaQueryWrapper<Book> lqw = new LambdaQueryWrapper<Book>();
    lqw.like(Book::getName,"Spring");
    bookDao.selectPage(page,lqw);
}

@Test
void testGetByCondition2(){
    QueryWrapper<Book> qw = new QueryWrapper<Book>();
    qw.like("name","Spring");
    bookDao.selectList(qw);
}

@Test
void testGetByCondition(){
    String name = "Spring";
    IPage page = new Page(1,10);
    LambdaQueryWrapper<Book> lqw = new LambdaQueryWrapper<Book>();
    lqw.like(Strings.isNotEmpty(name),Book::getName,"Spring");
    bookDao.selectPage(page,lqw);
}

# Service層接口定義與數(shù)據(jù)層接口定義具有較大區(qū)別，不要混用

// 業(yè)務(wù)層關(guān)注的是業(yè)務(wù)操作
login(String username,String password);

// 數(shù)據(jù)層關(guān)注的是數(shù)據(jù)庫(kù)操作
selectByUserNameAndPassword(String username,String password);

// 接口定義
public interface BookService {

    boolean save(Book book);
    boolean delete(Integer id);
    boolean update(Book book);
    Book getById(Integer id);
    List<Book> getAll();

    IPage<Book> getByPage(int currentPage,int pageSize);
}

// 實(shí)現(xiàn)類(lèi)定義
@Service
public class BookServiceImpl implements BookService {

    @Autowired
    private BookDao bookDao;

    public Boolean save(Book book) {
        return bookDao.insert(book) > 0; 
    }

    public Boolean delete(Integer id) {
        return bookDao.deleteById(id) > 0; 
    }
    public Boolean update(Book book) {
        return bookDao.updateById(book) > 0; 
    } 
    public Book getById(Integer id) {
        return bookDao.selectById(id);
    }
    public List<Book> getAll() {
        return bookDao.selectList(null);
    }
    public IPage<Book> getByPage(int currentPage, int pageSize) {
        IPage page = new Page<Book>(currentPage,pageSize);
        return bookDao.selectPage(page,null);
    }
}

public interface BookService extends IService<Book> {

    // 追加的操作與原始操作通過(guò)名稱(chēng)區(qū)分，功能類(lèi)似
    boolean saveBook(Book book);
    boolean modify(Book book);
    boolean delete(Integer id);
    IPage<Book> getPage(int currentPage, int pageSize);
    IPage<Book> getPage(int currentPage, int pageSize, Book book);
}

@Service
public class BookServiceImpl extends ServiceImpl<BookDao, Book> implements BookService {
    @Autowired
    private BookDao bookDao;
    @Override
    public boolean saveBook(Book book) {
        return bookDao.insert(book) > 0;
    }
    @Override
    public boolean modify(Book book) {
        return bookDao.updateById(book) > 0;
    }
    @Override
    public boolean delete(Integer id) {
        return bookDao.deleteById(id) > 0;
    }

    @Override
    public IPage<Book> getPage(int currentPage, int pageSize) {
        IPage page = new Page(currentPage, pageSize);
        bookDao.selectPage(page, null);
        return page;
    }
    @Override
    public IPage<Book> getPage(int currentPage, int pageSize, Book book) {
        LambdaQueryWrapper<Book> lqw = new LambdaQueryWrapper<Book>();
        lqw.like(Strings.isNotEmpty(book.getType()), Book::getType, book.getType());
        lqw.like(Strings.isNotEmpty(book.getName()), Book::getName, book.getName());
        lqw.like(Strings.isNotEmpty(book.getDescription()), Book::getDescription, book.getDescription());
        IPage page = new Page(currentPage, pageSize);
        bookDao.selectPage(page, lqw);
        return page;
    }
}

// 功能測(cè)試
@GetMapping("/{currentPage}/{pageSize}")
public R getPage(@PathVariable int currentPage, @PathVariable int pageSize, Book book) {

    IPage<Book> page = bookService.getPage(currentPage, pageSize, book);
    // 如果當(dāng)前頁(yè)碼大于了總頁(yè)碼，那么將最大頁(yè)碼值作為當(dāng)前頁(yè)碼，重新執(zhí)行查詢(xún)操作
    // 源碼中  long pages = this.getTotal() / this.getSize();
    if (currentPage > page.getPages()) {
        page = bookService.getPage((int) page.getPages(), pageSize, book);
    }
    return new R(true, page);
}    

//列表
getAll() {
    axios.get("/books").then((res)=>{
    		console.log(res.data);
    });
},

//列表
getAll() {
    axios.get("/books").then((res)=>{
    		this.dataList = res.data.data;
    });
},

//彈出添加窗口
handleCreate() {
    this.dialogFormVisible = true;
},
  
//清除數(shù)據(jù)，重置表單
resetForm() {
		this.formData = {};
},
  
//彈出添加窗口
handleCreate() {
		this.dialogFormVisible = true;
		this.resetForm();
},  
  
//添加
handleAdd () {
		//發(fā)送異步請(qǐng)求
		axios.post("/books",this.formData).then((res)=>{
				//如果操作成功，關(guān)閉彈層，顯示數(shù)據(jù)
				if(res.data.flag){
						this.dialogFormVisible = false;
						this.$message.success("添加成功");
				}else {
					this.$message.error("添加失敗");
				}
		}).finally(()=>{
				this.getAll();
		});
},  
  
//取消添加
cancel(){
		this.dialogFormVisible = false;
		this.$message.info("操作取消");
},  

// 刪除
handleDelete(row) {
    axios.delete("/books/"+row.id).then((res)=>{
        if(res.data.flag){
            this.$message.success("刪除成功");
        }else{
            this.$message.error("刪除失敗");
        }
    }).finally(()=>{
        this.getAll();
    });
}

// 刪除
handleDelete(row) {
    //1.彈出提示框
    this.$confirm("此操作永久刪除當(dāng)前數(shù)據(jù)，是否繼續(xù)？","提示",{
        type:'info'
    }).then(()=>{
        //2.做刪除業(yè)務(wù)
        axios.delete("/books/"+row.id).then((res)=>{
        ……
        }).finally(()=>{
            this.getAll();
        });
    }).catch(()=>{
        //3.取消刪除
        this.$message.info("取消刪除操作");
    });
}

//彈出編輯窗口
handleUpdate(row) {
    axios.get("/books/"+row.id).then((res)=>{
        if(res.data.flag){
            //展示彈層，加載數(shù)據(jù)
            this.formData = res.data.data;
            this.dialogFormVisible4Edit = true; 
        }else{
            this.$message.error("數(shù)據(jù)同步失敗，自動(dòng)刷新"); }
        });
},

//刪除
handleDelete(row) {
    axios.delete("/books/"+row.id).then((res)=>{
        if(res.data.flag){
            this.$message.success("刪除成功");
        }else{
            this.$message.error("數(shù)據(jù)同步失敗，自動(dòng)刷新"); 
        }
    }).finally(()=>{
        this.getAll();
    });
}

//修改
handleEdit() {
    axios.put("/books",this.formData).then((res)=>{
        //如果操作成功，關(guān)閉彈層并刷新頁(yè)面
        if(res.data.flag){
            this.dialogFormVisible4Edit = false;
            this.$message.success("修改成功");
        }else {
            this.$message.error("修改失敗，請(qǐng)重試");
        }
    }).finally(()=>{
        this.getAll();
    });
},
  
// 取消添加和修改
cancel(){
    this.dialogFormVisible = false;
    this.dialogFormVisible4Edit = false;
    this.$message.info("操作取消");
},

// 作為springmvc的異常處理器
@RestControllerAdvice
public class ProjectExceptionAdvice {

    // 攔截所有的異常信息
    @ExceptionHandler(Exception.class)
    public R doException(Exception e){
        // 記錄日志
        // 通知運(yùn)維
        // 通知開(kāi)發(fā)
        e.printStackTrace();
        return new R("服務(wù)器故障，請(qǐng)稍后重試哈！");
    }
}