sprintboot + mybaits + mysql + html5 + thymeleaf 个人笔记

参考：https://github.com/daleiwang/moxi

service

@Mapper 与 @Select 等

@Mapper似乎是一个myBaits 注解，表示将java方法和sql操作映射起来

sql语句里的用井号和花括号括起来的参数，对应实体类里的各个同名属性

例如#{userName} 对应了 参数admin对象的userName属性

@Mapper   //   mapper似乎是一个myBaits 注解，表示将java方法和sql操作映射起来
public interface AdminService {
    //sql语句里的用井号和花括号括起来的参数，对应实体类里的各个同名属性
    //例如#{userName}  对应了    参数admin对象的userName属性
    @Select("SELECT * FROM `moxi`.`admin` where userName = #{userName} and password = #{password} ;")
    Admin findByNameAndPassword(Admin admin);

    @Select("SELECT * FROM `moxi`.`admin` where userName = #{userName} and password = #{password} and realName = #{realName}")
    List<Admin> findByAdminWithPage(Admin admin, int start, int end);

    @Insert("INSERT INTO `moxi`.`admin` (`id`, `userName`, `password`, `realName`, `age`, `phoneNumber`, `headPicture`, `addDate`, `updateDate`, `state`) VALUES (null, #{userName}, #{password}, #{realName}, #{age}, #{phoneNumber}, #{headPicture}, now(), now(), 0);")
    int insert(Admin admin);

    @Update("UPDATE `moxi`.`admin` SET `userName` = #{userName}, `password` = #{password}, `realName` = #{realName}, `age` = #{age}, `phoneNumber` = #{phoneNumber}, `headPicture` = #{headPicture}, `updateDate` = now(), `state` = #{state} WHERE `id` = #{id};")
    int updateStateById(int id);

    @Delete("DELETE FROM `moxi`.`admin` WHERE id  = #{id}")
    int deleteById(int id);
}

controller

如何知道每个url对应哪个html

当我看上面这个github里的项目，包括其中readme里提供的简书教程时，我很疑惑，怎样知道每个url对应哪个html文件。

后来弄懂了，大致如下：

1. 把html文件放在项目根目录/src/main/resources/static文件夹下，
   
   如果用了thymeleaf 就放在/src/main/resources/template文件夹下.
   
   这里我们用了thymelead，所有选择后者
2. 有@RequestMapping(一串url)注解的函数，最后返回该html在static目录下的完整路径，不含html后缀。例如想以"localhost:8080/test"这个url，跳转到template文件夹下的test.html ，就让该函数return "test";

下面是两个例子：

	/**
	 * 登录跳转:使"localhost:8080/admin/login"路径对应template 下的login.html 文件
	 *
	 * @param model
	 * @return
	 */
	@GetMapping("/admin/login")
	public String loginGet(Model model) {
		return "login";
	}

@RequestMapping("/admin/newsManage_{pageCurrent}_{pageSize}_{pageCount}")
//表示该函数处理 括号中的url里的请求，包括get、post等
	public String newsManage(News news,@PathVariable Integer pageCurrent,@PathVariable Integer pageSize,@PathVariable Integer pageCount, Model model) {
                //blabala
		return "news/newsManage";       //表示运用到static文件加下，news文件夹下，文件名为newsManage.html的html文件
	}//这样一来/admin/newsManage_{pageCurrent}_{pageSize}_{pageCount}  这个路径显示的就是newsManage.html这个html文件的内容

遇到过的错误

1. 启动错误：org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'studentController': Unsatisfied dependency expressed through field 'studentService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'studentService' defined in file [C:\Users\yuqiao\Desktop\test\target\classes\com\example\test\service\StudentService.class]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: org.apache.ibatis.builder.BuilderException: Could not find value method on SQL annotation. Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 66; XML 文档结构必须从头至尾包含在同一个实体内。

StudentService中的sql语句写错，漏删了

1. 路由错误：
   
   This application has no explicit mapping for /error, so you are seeing this as a fallback.

Sat Dec 23 15:25:59 CST 2017

There was an unexpected error (type=Not Found, status=404).

No message available

原因@RequestMapping 写的位置不对，应该写在方法实现的上方，类的里面；我写在了类的上方

1. 实体类缺set和get方法
   
   There was an unexpected error (type=Internal Server Error, status=500).
   
   An error happened during template parsing (template: "class path resource [templates/index.html]")

在idea里翻报错，有一句：Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1008E: Property or field 'major' cannot be found on object of type 'com.example.test.model.Student' - maybe not public or not valid?

再找实体类Student，发现里面缺了major属性的get和set方法