修复当mapper目录没有mapper的xml配置文件的时候，启动报错的问题

src/main/java/com/company/project/configurer/MybatisConfigurer.java

@@ -4,17 +4,19 @@
 import org.apache.ibatis.plugin.Interceptor;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.mybatis.spring.SqlSessionFactoryBean;
-import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
 import org.springframework.core.io.support.ResourcePatternResolver;
+import org.springframework.util.ObjectUtils;
 import tk.mybatis.spring.mapper.MapperScannerConfigurer;
 
 import javax.annotation.Resource;
 import javax.sql.DataSource;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Properties;
 
 import static com.company.project.core.ProjectConstant.*;
@@ -24,45 +26,81 @@
  */
 @Configuration
 public class MybatisConfigurer {
+    @Resource
+    private DataSource dataSource;
 
     @Bean
-    public SqlSessionFactory sqlSessionFactoryBean(DataSource dataSource) throws Exception {
+    public SqlSessionFactory sqlSessionFactoryBean() throws Exception {
         SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
         factory.setDataSource(dataSource);
         factory.setTypeAliasesPackage(MODEL_PACKAGE);
 
         //配置分页插件，详情请查阅官方文档
         PageHelper pageHelper = new PageHelper();
         Properties properties = new Properties();
-        properties.setProperty("pageSizeZero", "true");//分页尺寸为0时查询所有纪录不再执行分页
-        properties.setProperty("reasonable", "true");//页码<=0 查询第一页，页码>=总页数查询最后一页
-        properties.setProperty("supportMethodsArguments", "true");//支持通过 Mapper 接口参数来传递分页参数
+        //分页尺寸为0时查询所有纪录不再执行分页
+        properties.setProperty("pageSizeZero", "true");
+        //页码<=0 查询第一页，页码>=总页数查询最后一页
+        properties.setProperty("reasonable", "true");
+        //支持通过 Mapper 接口参数来传递分页参数
+        properties.setProperty("supportMethodsArguments", "true");
         pageHelper.setProperties(properties);
 
         //添加插件
         factory.setPlugins(new Interceptor[]{pageHelper});
 
         //添加XML目录
         ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
-        factory.setMapperLocations(resolver.getResources("classpath:mapper/*.xml"));
+        //如果没有此目录的话，后续初始化SqlSessionFactory会报错，这里参考MybatisProperties的代码
+        //这样纯使用注解，没有mapper目录也可以了
+        org.springframework.core.io.Resource[] resources = null;
+        if (!ObjectUtils.isEmpty(resources = resolveMapperLocations("classpath:mapper/**/*.xml"))) {
+            factory.setMapperLocations(resources);
+        }
         return factory.getObject();
     }
 
-    @Bean
-    public MapperScannerConfigurer mapperScannerConfigurer() {
-        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
-        mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactoryBean");
-        mapperScannerConfigurer.setBasePackage(MAPPER_PACKAGE);
+    @Configuration
+    @AutoConfigureAfter(MybatisConfigurer.class)
+    public static class MyBatisMapperScannerConfigurer {
 
-        //配置通用Mapper，详情请查阅官方文档
-        Properties properties = new Properties();
-        properties.setProperty("mappers", MAPPER_INTERFACE_REFERENCE);
-        properties.setProperty("notEmpty", "false");//insert、update是否判断字符串类型!='' 即 test="str != null"表达式内是否追加 and str != ''
-        properties.setProperty("IDENTITY", "MYSQL");
-        mapperScannerConfigurer.setProperties(properties);
+        @Bean
+        public MapperScannerConfigurer mapperScannerConfigurer() {
+            MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
+            mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactoryBean");
+            mapperScannerConfigurer.setBasePackage(MAPPER_PACKAGE);
+            //配置通用mappers，详情请查阅官方文档
+            Properties properties = new Properties();
+            properties.setProperty("mappers", MAPPER_INTERFACE_REFERENCE);
+            //insert、update是否判断字符串类型!='' 即 test="str != null"表达式内是否追加 and str != ''
+            properties.setProperty("notEmpty", "false");
+            properties.setProperty("IDENTITY", "MYSQL");
+            mapperScannerConfigurer.setProperties(properties);
+
+            return mapperScannerConfigurer;
+        }
 
-        return mapperScannerConfigurer;
     }
 
+    public org.springframework.core.io.Resource[] resolveMapperLocations(String... mapperLocations) {
+
+        PathMatchingResourcePatternResolver resourceResolver = new PathMatchingResourcePatternResolver();
+        ArrayList resources = new ArrayList();
+        if(mapperLocations != null) {
+            int total = mapperLocations.length;
+
+            for(int i = 0; i < total; ++i) {
+                String mapperLocation = mapperLocations[i];
+                try {
+                    org.springframework.core.io.Resource[] mappers = resourceResolver.getResources(mapperLocation);
+                    resources.addAll(Arrays.asList(mappers));
+                } catch (IOException ex) {
+                    ;
+                }
+            }
+        }
+
+        return (org.springframework.core.io.Resource[])resources.toArray(new org.springframework.core.io.Resource[resources.size()]);
+    }
 }
 

src/main/java/com/company/project/core/ResultCode.java

@@ -1,14 +1,14 @@
 package com.company.project.core;
 
 /**
- * 响应码枚举，参考HTTP状态码的语义
+ * 响应码枚举，参考微信全局返回码说明
  */
 public enum ResultCode {
-    SUCCESS(200),//成功
-    FAIL(400),//失败
-    UNAUTHORIZED(401),//未认证（签名错误）
-    NOT_FOUND(404),//接口不存在
-    INTERNAL_SERVER_ERROR(500);//服务器内部错误
+    SUCCESS(0),//请求成功
+    FAIL(40000),//请求失败(比如请求参数不匹配，请求body之类的错误)
+    UNAUTHORIZED(40001),//未认证（签名错误）
+    NOT_FOUND(40004),//接口不存在
+    INTERNAL_SERVER_ERROR(-1);//服务器内部错误,系统繁忙
 
     private final int code;