com.jeesuite.mybatis.crud.helper.EntityHelper Maven / Gradle / Ivy
package com.jeesuite.mybatis.crud.helper;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Transient;
import com.jeesuite.mybatis.core.BaseEntity;
public class EntityHelper {
/**
* 缓存TableMapper
*/
private final static Map, EntityMapper> tableMapperCache = new HashMap, EntityMapper>();
/**
* 由传入的实体的class构建TableMapper对象，构建好的对象存入缓存中，以后使用时直接从缓存中获取
*
* @param entityClass
* @return TableMapper
*/
public static EntityMapper getEntityMapper(Class entityClass) {
synchronized (entityClass) {
// 先从map中获取实体映射信息
EntityMapper entityMapper = tableMapperCache.get(entityClass);
// 如果存在直接返回
if (entityMapper != null) {
return entityMapper;
}
TableMapper tableMapper = getTableMapper(entityClass);
//获取实体ID泛型
Class idClass = getIdClass(entityClass);
// 获取实体字段列表
List fields = getAllField(entityClass);
// 全部列
Set columnMapperSet = new HashSet();
// 主键
ColumnMapper idColumn = null;
GenerationType idStrategy = null;
for (Field field : fields) {
// 排除字段
if (field.isAnnotationPresent(Transient.class)) {
continue;
}
ColumnMapper columnMapper = new ColumnMapper();
// 数据库字段名
String columnName = null;
if (field.isAnnotationPresent(Column.class)) {
Column column = field.getAnnotation(Column.class);
columnName = column.name();
columnMapper.setInsertable(column.insertable());
columnMapper.setUpdatable(column.updatable());
}
// 如果为空，使用属性名并替换为下划线风格
if (columnName == null || columnName.equals("")) {
columnName = camelhumpToUnderline(field.getName());
}
columnMapper.setProperty(field.getName());
columnMapper.setColumn(columnName);
columnMapper.setJavaType(field.getType());
// 是否主键
if(field.isAnnotationPresent(Id.class)){
columnMapper.setId(true);
if(field.isAnnotationPresent(GeneratedValue.class)){
idStrategy = field.getAnnotation(GeneratedValue.class).strategy();
}
idColumn = columnMapper;
}
// 添加到所有字段映射信息
columnMapperSet.add(columnMapper);
}
if (columnMapperSet.size() <= 0) {
throw new RuntimeException("实体" + entityClass.getName() + "不存在映射字段");
}
if (idColumn == null) {
throw new RuntimeException("实体" + entityClass.getName() + "不存在主键");
}
// 解析实体映射信息
entityMapper = new EntityMapper();
entityMapper.setTableMapper(tableMapper);
entityMapper.setColumnsMapper(columnMapperSet);
entityMapper.setIdClass(idClass);
entityMapper.setIdColumn(idColumn);
entityMapper.setIdStrategy(idStrategy);
tableMapperCache.put(entityClass, entityMapper);
return entityMapper;
}
}
/**
* 获取实体的ID泛型
* @param entityClass
* @return
*/
private static Class getIdClass(Class entityClass) {
Type[] genTypes = entityClass.getGenericInterfaces();
for (int i = 0; i < genTypes.length; i++) {
Type genType = genTypes[i];
String s1 = genType.getClass().getName();
String s2 = BaseEntity.class.getName();
if (s1.startsWith(s2)) {
Type[] params = ((ParameterizedType) genType).getActualTypeArguments();
// ID真实的class
Class mapperClass = (Class) params[0];
return mapperClass;
}
}
return null;
}
// 获取实体Table映射信息
private static TableMapper getTableMapper(Class entityClass) {
// 表名
TableMapper tableMapper = new TableMapper();
String tableName = null;
if (entityClass.isAnnotationPresent(Table.class)) {
Table table = entityClass.getAnnotation(Table.class);
if (!table.name().equals("")) {
tableName = table.name();
} else {
tableName = camelhumpToUnderline(entityClass.getSimpleName());
}
}
if (tableName == null || tableName.equals("")) {
throw new RuntimeException("实体" + entityClass.getName() + "不存在'Table'注解");
}
tableMapper.setName(tableName);
return tableMapper;
}
/**
* 将驼峰风格替换为下划线风格
*/
private static String camelhumpToUnderline(String str) {
final int size;
final char[] chars;
final StringBuilder sb = new StringBuilder((size = (chars = str.toCharArray()).length) * 3 / 2 + 1);
char c;
for (int i = 0; i < size; i++) {
c = chars[i];
if (isUppercaseAlpha(c)) {
sb.append('_').append(c);
} else {
sb.append(toUpperAscii(c));
}
}
String result = sb.charAt(0) == '_' ? sb.substring(1) : sb.toString();
return result.toLowerCase();
}
private static boolean isUppercaseAlpha(char c) {
return (c >= 'A') && (c <= 'Z');
}
private static char toUpperAscii(char c) {
if (isUppercaseAlpha(c)) {
c -= (char) 0x20;
}
return c;
}
/**
* 获取全部的Field
*
* @param entityClass
* @param fieldList
* @return
*/
private static List getAllField(Class entityClass) {
return getAllField(entityClass, null);
}
/**
* 获取全部的Field
*
* @param entityClass
* @param fieldList
* @return
*/
private static List getAllField(Class entityClass, List fieldList) {
if (fieldList == null) {
fieldList = new ArrayList();
}
if (entityClass.equals(Object.class)) {
return fieldList;
}
Field[] fields = entityClass.getDeclaredFields();
for (Field field : fields) {
// 排除静态字段
if (!Modifier.isStatic(field.getModifiers())) {
fieldList.add(field);
}
}
Class superClass = entityClass.getSuperclass();
if (superClass != null && !superClass.equals(Object.class)
&& (!Map.class.isAssignableFrom(superClass) && !Collection.class.isAssignableFrom(superClass))) {
return getAllField(entityClass.getSuperclass(), fieldList);
}
return fieldList;
}
}