package com.fpi.notify.config;
 
import com.google.common.base.CaseFormat;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.wrapper.MapWrapper;
import org.apache.ibatis.reflection.wrapper.ObjectWrapper;
import org.apache.ibatis.reflection.wrapper.ObjectWrapperFactory;
import org.mybatis.spring.boot.autoconfigure.ConfigurationCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration; 
import java.util.Map;
 
/**
 * mybatis查詢Map返回值下劃線轉峰坨
 * @author xingxing_yuan
 * @since 2020-02-18 13:47
 */
@Configuration
public class MybatisCamelConfig {
 @Bean
 public ConfigurationCustomizer mybatisConfigurationCustomizer() {
//   使用自定義的解析器工廠
  return configuration -> configuration.setObjectWrapperFactory(new MapWrapperFactory());
 }
 
 /**
  * 實現(xiàn)工廠
  */
 static class MapWrapperFactory implements ObjectWrapperFactory {
  @Override
  public boolean hasWrapperFor(Object object) {
//  判斷是Map就使用該解析
   return object instanceof Map;
  }
 
  @Override
  public ObjectWrapper getWrapperFor(MetaObject metaObject, Object object) {
//  將默認的解析器替換成峰坨轉換
   return new CamelWrapper(metaObject, (Map) object);
  }
 }
 
 /**
  * 重寫轉換器；添加轉換方法
  */
 static class CamelWrapper extends MapWrapper {
 
  CamelWrapper(MetaObject metaObject, Map<String, Object> map) {
   super(metaObject, map);
  }
 
  /**
   * mybatis查詢結果下劃線轉峰坨
   *
   * @param name
   * @param useCamelCaseMapping 是否進行轉換。yaml 中配置map-underscore-to-camel-case=true
   * @return
   */
  @Override
  public String findProperty(String name, boolean useCamelCaseMapping) {
   if (useCamelCaseMapping) {
//    使用guava的轉換方法,覆蓋Map的默認返回值
    return CaseFormat.UPPER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, name);
   }
   return name;
  }
 
 }
}

public class CustomWrapper extends MapWrapper{
 
 public CustomWrapper(MetaObject metaObject, Map<String, Object> map) {
 super(metaObject, map);
 }
 
 @Override
 public String findProperty(String name, boolean useCamelCaseMapping) {
 if(useCamelCaseMapping){
   //CaseFormat是引用的 guava庫,里面有轉換駝峰的,免得自己重復造輪子,pom添加
   /**
    **   <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>
       <version>24.1-jre</version>
       </dependency>
    **/
 return CaseFormat.UPPER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL,name);
 }
 return name;
 }
}

public class MapWrapperFactory implements ObjectWrapperFactory {
 @Override
 public boolean hasWrapperFor(Object object) {
 return object != null && object instanceof Map;
 }
 @Override
 public ObjectWrapper getWrapperFor(MetaObject metaObject, Object object) {
 return new CustomWrapper(metaObject,(Map)object);
 }
}

@Configuration
public class MybatisConfig {
 
 @Bean
 public ConfigurationCustomizer mybatisConfigurationCustomizer(){
 return new ConfigurationCustomizer() {
 @Override
 public void customize(org.apache.ibatis.session.Configuration configuration) {
 configuration.setObjectWrapperFactory(new MapWrapperFactory());
 }
 };
 }
}

@Override
 public String findProperty(String name, boolean useCamelCaseMapping) {
 if (useCamelCaseMapping
    && ((name.charAt(0) >= 'A' && name.charAt(0) <= 'Z')
     || name.indexOf("_") >= 0)) {
   return underlineToCamelhump(name);
  }
  return name;
 }
 private String underlineToCamelhump(String inputString) {
  StringBuilder sb = new StringBuilder();
  boolean nextUpperCase = false;
  for (int i = 0; i < inputString.length(); i++) {
   char c = inputString.charAt(i);
   if (c == '_') {
    if (sb.length() > 0) {
     nextUpperCase = true;
    }
   } else {
    if (nextUpperCase) {
     sb.append(Character.toUpperCase(c));
     nextUpperCase = false;
    } else {
     sb.append(Character.toLowerCase(c));
    }
   }
  }
  return sb.toString();
 }