11.Bean2Document-BEAN转document

1.

 package com.glodon.gspm.adapter.plugin.common;

 import com.glodon.cloudt.tenancy.context.TenantContext;
 import org.bson.Document;
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.BeanWrapper;
 import org.springframework.beans.PropertyAccessorFactory;
 import org.springframework.util.StringUtils;

 import java.beans.PropertyDescriptor;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;

 /**
  * 实体对象转Document类
  * Created by hezg on 2017/4/4.
  */
 public class Bean2Document<T> {

     //字段前缀
     private static final char COLUMN_PREFIX = 'F';
     //单词分隔符
     private static final char UNDER_LINE = '_';
     //字段属性映射
     private transient Map<String, PropertyDescriptor> mappedFields;

     private static Map<Class<?>, Bean2Document> mapperMap = new ConcurrentHashMap<>();

     public Bean2Document(Class<T> mappedClass) {
         initialize(mappedClass);
     }

     /**
      * 创建一个新的Bean2Document类
      *
      * @param mappedClass 需要映射的实体类
      */
     @SuppressWarnings("unchecked")
     public static <T> Bean2Document<T> newInstance(Class<T> mappedClass) {
         Bean2Document mapper = mapperMap.get(mappedClass);
         if (mapper == null) {
             mapper = new Bean2Document<>(mappedClass);
             mapperMap.put(mappedClass, mapper);
         }
         return (Bean2Document<T>) mapper;
     }

     /**
      * 将实体属性初始化到mappedFields中
      *
      * @param mappedClass 需要初始化的实体类
      */
     @SuppressWarnings("Duplicates")
     protected void initialize(Class<T> mappedClass) {
         this.mappedFields = new HashMap<>();
         PropertyDescriptor[] pds = BeanUtils.getPropertyDescriptors(mappedClass);
         for (PropertyDescriptor pd : pds) {
             if (pd.getWriteMethod() != null) {
                 this.mappedFields.put(pd.getName().toUpperCase(), pd);
             }
         }
     }

     /**
      * 将实体字段名转换为表字段名
      *
      * @param name 实体字段
      * @return 返回对应表字段名
      */
     @SuppressWarnings("Duplicates")
     private String underscoreName(String name) {
         if (!StringUtils.hasLength(name)) {
             return "";
         }
         // 添加字段前缀
         StringBuilder result = new StringBuilder();
         if (!StringUtils.isEmpty(COLUMN_PREFIX)) {
             result.append(COLUMN_PREFIX).append(UNDER_LINE);
         }
         result.append(name.substring(0, 1).toUpperCase());
         for (int i = 1; i < name.length(); i++) {
             String ss = name.substring(i, i + 1);
             String slc = ss.toUpperCase();
             if (ss.equals(slc)) {
                 result.append(UNDER_LINE).append(slc);
             } else {
                 result.append(slc);
             }
         }
         return result.toString();
     }

     /**
      * 将实体数据格式转换为Document格式
      *
      * @param data 实体数据
      * @return Document格式数据
      */
     public Document toDocument(T data) {
         if (data == null) {
             return null;
         }

         Document document = new Document();
         BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(data);
         for (PropertyDescriptor pd : this.mappedFields.values()) {
             Object value = bw.getPropertyValue(pd.getName());
             String underscoredName = underscoreName(pd.getName());
             document.put(underscoredName, value);
         }
         //Mongo同一接口，所有类转Document时都带上租户Id
         long tenantId = TenantContext.getCurrent()
                 .getTenantId();

         document.put("F_TENANT_ID", tenantId);
         return document;
     }
 }