最近一直在研究Spring Boot。从GitHub上下载了一个my-Blog源码，一边看，一边自己尝试去实现，结果掉在坑了，研究了近一周才爬出来，特地来这博客园记录下来，一是避免自己在放这样的错误，二是希望看到的朋友能有所帮助，毕竟我在网上查了很多资料，答案基本上千篇一律，并不能解决我的问题。
先说问题：我在Controller层中引用Service层的实现类，报错，错误代码如下：
2020-06-21 22:49:45.094 ERROR 1552 --- [nio-8081-exec-6] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.example.mydemo.service.AdminUserService.login] with root cause
org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.example.mydemo.service.AdminUserService.login
at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:235) ~[mybatis-3.5.4.jar:3.5.4]
at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:53) ~[mybatis-3.5.4.jar:3.5.4]
at org.apache.ibatis.binding.MapperProxy.lambda$cachedInvoker$0(MapperProxy.java:107) ~[mybatis-3.5.4.jar:3.5.4]
at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660) ~[na:1.8.0_151]
at org.apache.ibatis.binding.MapperProxy.cachedInvoker(MapperProxy.java:94) ~[mybatis-3.5.4.jar:3.5.4]
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:85) ~[mybatis-3.5.4.jar:3.5.4]
at com.sun.proxy.$Proxy66.login(Unknown Source) ~[na:na]
at com.example.mydemo.controller.admin.AdminController.login(AdminController.java:45) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_151]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_151]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_151]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_151]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:215) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:142) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:998) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:901) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:875) ~[spring-webmvc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:770) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415) [tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.12.jar:9.0.12]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_151]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_151]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.12.jar:9.0.12]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_151]
总的来说就是绑定语句无效，并未找到 com.example.mydemo.service.AdminUserService.login此方法。我从网上百度一下，看到大多数都是再讲Mapper.xml设置错误导致，需要排查：
- 检查xml文件所在package名称是否和Mapper interface所在的包名一一对应；
- 检查xml的namespace是否和xml文件的package名称一一对应；
- 检查方法名称是否对应；
但我看了很多遍，我的程序都没有这些问题，并且我在Test中测试Mapper时可以用的。
@SpringBootTest
class MydemoApplicationTests {
@Autowired
AdminUserMapper adminUserMapper;
@Resource
TestService testService;
@Test
void TestInsert(){
AdminUser adminUser =new AdminUser();
adminUser.setAdminUserId(5);
adminUser.setLocked(Byte.parseByte("1"));
adminUser.setLoginPassword("123");
adminUser.setLoginUserName("zzc");
adminUser.setNickName("BigBang");
adminUserMapper.insert(adminUser);
}
@Test
void get(){
AdminUser get= adminUserMapper.login("zzc","123");
System.out.println(get);
}
@Test
void TestMyService(){
testService.Test();
}
}
2020-06-21 22:59:08.234 INFO 10652 --- [ main] c.example.mydemo.MydemoApplicationTests : Starting MydemoApplicationTests on LAPTOP-MFBL0MLV with PID 10652 (started by zc in D:\Lab_Java\Demo)
2020-06-21 22:59:08.236 INFO 10652 --- [ main] c.example.mydemo.MydemoApplicationTests : No active profile set, falling back to default profiles: default
2020-06-21 22:59:10.117 INFO 10652 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2020-06-21 22:59:10.814 INFO 10652 --- [ main] c.example.mydemo.MydemoApplicationTests : Started MydemoApplicationTests in 2.776 seconds (JVM running for 4.072)
2020-06-21 22:59:11.102 INFO 10652 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2020-06-21 22:59:11.287 INFO 10652 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
AdminUser{adminUserId=1, loginUserName='zzc', loginPassword='123', nickName='BigBang', locked=0}
2020-06-21 22:59:11.356 INFO 10652 --- [ Thread-2] o.s.s.concurrent.ThreadPoolTaskExecutor : Shutting down ExecutorService 'applicationTaskExecutor'
2020-06-21 22:59:11.357 INFO 10652 --- [ Thread-2] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated...
2020-06-21 22:59:11.359 INFO 10652 --- [ Thread-2] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed.
Process finished with exit code 0
可以看到get()方法是可以使用adminUserMapper的，也就是说Mapper的注入是没有问题的。此外还写了一个TestService，里面不涉及任何Mapper相关的东西，还是报这个错误。也就是说我的问题原因和Mapper并没有关系，至少不是上述这三点导致的。
问题还是出现再Service层里，我的Service层代码如下：
package com.example.mydemo.service;
import com.example.mydemo.entity.AdminUser;
public interface AdminUserService {
AdminUser login(String userName, String password);
/**
* 获取用户信息
*
* @param loginUserId
* @return
*/
AdminUser getUserDetailById(Integer loginUserId);
/**
* 修改当前登录用户的密码
*
* @param loginUserId
* @param originalPassword
* @param newPassword
* @return
*/
Boolean updatePassword(Integer loginUserId, String originalPassword, String newPassword);
/**
* 修改当前登录用户的名称信息
*
* @param loginUserId
* @param loginUserName
* @param nickName
* @return
*/
Boolean updateName(Integer loginUserId, String loginUserName, String nickName);
}
package com.example.mydemo.service.impl;
import com.example.mydemo.dao.AdminUserMapper;
import com.example.mydemo.entity.AdminUser;
import com.example.mydemo.service.AdminUserService;
import com.example.mydemo.util.MD5Util;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
@Service
public class AdminUserServiceImpl implements AdminUserService {
@Resource
private AdminUserMapper adminUserMapper;
@Override
public AdminUser login(String userName, String password) {
String passwordMd5 = MD5Util.MD5Encode(password, "UTF-8");
System.out.println("Md5:"+passwordMd5);
return adminUserMapper.login(userName, passwordMd5);
}
@Override
public AdminUser getUserDetailById(Integer loginUserId) {
return adminUserMapper.selectByPrimaryKey(loginUserId);
}
@Override
public Boolean updatePassword(Integer loginUserId, String originalPassword, String newPassword) {
AdminUser adminUser = adminUserMapper.selectByPrimaryKey(loginUserId);
//当前用户非空才可以进行更改
if (adminUser != null) {
String originalPasswordMd5 = MD5Util.MD5Encode(originalPassword, "UTF-8");
String newPasswordMd5 = MD5Util.MD5Encode(newPassword, "UTF-8");
//比较原密码是否正确
if (originalPasswordMd5.equals(adminUser.getLoginPassword())) {
//设置新密码并修改
adminUser.setLoginPassword(newPasswordMd5);
if (adminUserMapper.updateByPrimaryKeySelective(adminUser) > 0) {
//修改成功则返回true
return true;
}
}
}
return false;
}
@Override
public Boolean updateName(Integer loginUserId, String loginUserName, String nickName) {
AdminUser adminUser = adminUserMapper.selectByPrimaryKey(loginUserId);
//当前用户非空才可以进行更改
if (adminUser != null) {
//设置新密码并修改
adminUser.setLoginUserName(loginUserName);
adminUser.setNickName(nickName);
if (adminUserMapper.updateByPrimaryKeySelective(adminUser) > 0) {
//修改成功则返回true
return true;
}
}
return false;
}
}
package com.example.mydemo.controller.admin;
import com.example.mydemo.entity.AdminUser;
import com.example.mydemo.service.AdminUserService;
import org.springframework.stereotype.Controller;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
import javax.servlet.http.HttpSession;
@Controller
@RequestMapping("/admin")
public class AdminController {
@Resource
private AdminUserService adminUserService;
@GetMapping({"/login"})
public String login() {
return "admin/login";
}
@PostMapping(value = "/login")
public String login(@RequestParam("userName") String userName,
@RequestParam("password") String password,
@RequestParam("verifyCode") String verifyCode,
HttpSession session){
if (StringUtils.isEmpty(verifyCode)) {
session.setAttribute("errorMsg", "验证码不能为空");
return "admin/login";
}
if (StringUtils.isEmpty(userName) || StringUtils.isEmpty(password)) {
session.setAttribute("errorMsg", "用户名或密码不能为空");
return "admin/login";
}
String kaptchaCode = session.getAttribute("verifyCode") + "";
if (StringUtils.isEmpty(kaptchaCode) || !verifyCode.equals(kaptchaCode)) {
session.setAttribute("errorMsg", "验证码错误");
return "admin/login";
}
AdminUser adminUser = adminUserService.login(userName, password);
if (adminUser != null) {
session.setAttribute("loginUser", adminUser.getNickName());
session.setAttribute("loginUserId", adminUser.getAdminUserId());
//session过期时间设置为7200秒 即两小时
//session.setMaxInactiveInterval(60 * 60 * 2);
return "redirect:/admin/index";
} else {
session.setAttribute("errorMsg", "登陆失败");
return "admin/login";
}
}
}
package com.example.mydemo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.example.mydemo")
public class MydemoApplication {
public static void main(String[] args) {
SpringApplication.run(MydemoApplication.class, args);
}
}
在网上查资料，发现有人说如果Application类包所在的位置也很关键，SpringBoot项目的Bean装配默认规则是根据Application类所在的包位置从上往下扫描！Application类是指SpringBoot项目入口类。也就是我的Service层所在的包必须在com.example.mydemo或其子包下，否则Service层中的Bean不会被扫描到，但我的程序也满足啊。
果就在这里思索了一周都没有一点进展，直到一天我发现我的@MapperScan扫描的路径是"com.example.mydemo"。WTF!!!
我又赶快上网查了一下@MapperScan注解
作用：指定要变成实现类的接口所在的包，然后包下面的所有接口在编译之后都会生成相应的实现类
添加位置：是在Springboot启动类上面添加。
看到没，包下面所有的接口在编译后之后都会生成相应的实现类，也就是说除了我的AdminUserServiceImp外Spring Boot还注入了一个mapper实现类，当我在Controller中使用@AutoWired或@Resource获取时，获取到时这个Mapper实现类的实例，但实际上并没有真正继承AdminUserService接口，只有你在运行的时候服务器才会报错，找不到对应的方法。
于是我把Mapper扫描具体到DAO路径下，即：
package com.example.mydemo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.example.mydemo.dao")
public class MydemoApplication {
public static void main(String[] args) {
SpringApplication.run(MydemoApplication.class, args);
}
}
修改后果然不再报错。
其实这个错误说起来还是挺简单，主要时自己对Spring Boot的注解，一些基本知识还是不够了解导致，看来以后还是要继续夯实基础啊。
写在最后：
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