mybatis 枚举自动转换
基于springboot 整合mybatis tk.mybatis 修改配置没有生效，只好重写 EnumTypeHandler 类
springboot 中 mybatis configuration 配置失效问题:https://blog.csdn.net/Keith003/article/details/84289638
结构如下
1、创建 BaseEnums 枚举公用接口
import java.io.Serializable;
public interface BaseEnums,T> extends Serializable {
public String getLabel();
public T getValue();
} 2、重写 EnumTypeHandler 类
package org.apache.ibatis.type;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class EnumTypeHandler> extends BaseTypeHandler {
private BaseTypeHandler typeHandler = null;
public EnumTypeHandler(Class type) {
if (type == null) {
throw new IllegalArgumentException("Type argument cannot be null");
}
if(isInterface(type, "BaseEnums接口得全路径")){
// 如果实现了 BaseEnums 则使用我们自定义的转换器
typeHandler = new CurrencyEnumHandler(type);
}else {
// 默认转换器 也可换成 EnumOrdinalTypeHandler
typeHandler = new DefaultEnumTypeHandler<>(type);
}
}
@Override
public void setNonNullParameter(PreparedStatement ps, int i, E parameter, JdbcType jdbcType) throws SQLException {
typeHandler.setNonNullParameter(ps,i, parameter,jdbcType);
}
@Override
public E getNullableResult(ResultSet rs, String columnName) throws SQLException {
return (E) typeHandler.getNullableResult(rs,columnName);
}
@Override
public E getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
return (E) typeHandler.getNullableResult(rs,columnIndex);
}
@Override
public E getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
return (E) typeHandler.getNullableResult(cs,columnIndex);
}
/***************************************************************************
* 判断对象o实现的所有接口中是否有szInterface
* 2008-08-07修正多继承中判断接口的功能，
* 以及修正接口继承后的判断功能
* package test;
*
* public interfaceITest extends Serializable
* public classTest1 implements ITest
* public classTest2 extends Test1
* public classTest3 extends Test2
*
* isInterface(Test3.class,"java.io.Serializable")=true
* isInterface(Test3.class,"test.ITest")=true
* @paramc
* @paramsz Interface
* @return
*/
public boolean isInterface(Class c, String szInterface) {
Class[] face = c.getInterfaces();
for(int i=0,j = face.length; i 3、创建 DefaultEnumTypeHandler类 内容为mybatis 中 EnumTypeHandler 类内容 为了不影响除枚举外得转换
package org.apache.ibatis.type;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class DefaultEnumTypeHandler> extends BaseTypeHandler {
private final Class type;
public DefaultEnumTypeHandler(Class type) {
if (type == null) {
throw new IllegalArgumentException("Type argument cannot be null");
}
this.type = type;
}
@Override
public void setNonNullParameter(PreparedStatement ps, int i, E parameter, JdbcType jdbcType) throws SQLException {
if (jdbcType == null) {
ps.setString(i, parameter.name());
} else {
ps.setObject(i, parameter.name(), jdbcType.TYPE_CODE); // see r3589
}
}
@Override
public E getNullableResult(ResultSet rs, String columnName) throws SQLException {
String s = rs.getString(columnName);
return s == null ? null : Enum.valueOf(type, s);
}
@Override
public E getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
String s = rs.getString(columnIndex);
return s == null ? null : Enum.valueOf(type, s);
}
@Override
public E getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
String s = cs.getString(columnIndex);
return s == null ? null : Enum.valueOf(type, s);
}
}
4、创建 CurrencyEnumHandler类 自定义枚举转换类
package org.apache.ibatis.type;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
/**
* class_name: CurrencyEnumHandler
* package: org.apache.ibatis.type
* describe: 枚举转换类
* creat_date: 2018/11/19
* creat_time: 10:43
**/
public class CurrencyEnumHandler & BaseEnums> extends BaseTypeHandler{
private Class type;
/**
* 设置配置文件设置的转换类以及枚举类内容，供其他方法更便捷高效的实现
* @param type 配置文件中设置的转换类
*/
public CurrencyEnumHandler(Class type) {
if (type == null)
throw new IllegalArgumentException("Type argument cannot be null");
this.type = type;
}
/**
* class_name:
* param:
* describe: 用于定义设置参数时，该如何把 Java 类型的参数转换为对应的数据库类型
* creat_date: 2018/11/19
* creat_time: 11:34
**/
@Override
public void setNonNullParameter(PreparedStatement ps, int i, E parameter,
JdbcType jdbcType) throws SQLException {
//BaseTypeHandler已经帮我们做了parameter的null判断
if (jdbcType == null) {
ps.setObject(i, getFieldValueByFieldName("value",parameter));
} else {
ps.setObject(i, getFieldValueByFieldName("value",parameter), jdbcType.TYPE_CODE);
}
}
/**
* class_name:
* param:
* describe: 用于定义通过字段名称获取字段数据时，如何把数据库类型转换为对应的 Java 类型
* creat_date: 2018/11/19
* creat_time: 11:39
**/
@Override
public E getNullableResult(ResultSet rs, String columnName)
throws SQLException {
// 根据数据库存储类型决定获取类型
Object code = rs.getObject(columnName);
return rs.wasNull() ? null : codeOf(code);
}
/**
* class_name:
* param:
* describe: 用于定义通过字段索引获取字段数据时，如何把数据库类型转换为对应的 Java 类型
* creat_date: 2018/11/19
* creat_time: 11:41
**/
@Override
public E getNullableResult(ResultSet rs, int columnIndex)
throws SQLException {
Object code = rs.getObject(columnIndex);
return rs.wasNull() ? null : codeOf(code);
}
/**
* class_name:
* param:
* describe: 用定义调用存储过程后，如何把数据库类型转换为对应的 Java 类型
* creat_date: 2018/11/19
* creat_time: 11:42
**/
@Override
public E getNullableResult(CallableStatement cs, int columnIndex)
throws SQLException {
Object code = cs.getObject(columnIndex);
return cs.wasNull() ? null : codeOf(code);
}
/**
* class_name:
* param:
* describe: 获取枚举
* creat_date: 2018/11/19
* creat_time: 19:54
**/
private E codeOf(Object code){
try {
Method codeOf = type.getMethod("codeOf", Object.class);
Object invoke = codeOf.invoke(codeOf, code);
return (E)invoke;
} catch (Exception ex) {
throw new IllegalArgumentException("Cannot convert " + code + " to " + type.getSimpleName() + " by code value.", ex);
}
}
/**
* 根据属性名获取属性值
*
* @param fieldName
* @param object
* @return
*/
private Object getFieldValueByFieldName(String fieldName, Object object) {
try {
Field field = object.getClass().getDeclaredField(fieldName);
//设置对象的访问权限，保证对private的属性的访问
field.setAccessible(true);
return field.get(object);
} catch (Exception e) {
return null;
}
}
}
5、创建自己得枚举 实现BaseEnums 接口
package mmall.enums;
import com.fasterxml.jackson.annotation.JsonValue;
/**
* class_name: UpperLowerShelfStateEnum
* package: mmall.enums
* describe: 活动上下架枚举状态
* 0：待上架 1：上架 2：下架
* creat_date: 2018/11/19
* creat_time: 10:38
**/
public enum UpperLowerShelfStateEnum implements BaseEnums {
To_be_on_the_shelfteacher("待上架","0"),
On_the_shelf("上架","1"),
Lower_frame("下架","2");
private String value;
private String lable;
private UpperLowerShelfStateEnum(String lable, String value) {
this.value = value;
this.lable = lable;
}
@JsonValue
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
public String getLabel() {
return lable;
}
public void getLabel(String lable) {
this.lable = lable;
}
/**
* 通过value 值进行查找对应枚举
*/
public static UpperLowerShelfStateEnum codeOf(Object code){
UpperLowerShelfStateEnum[] values = UpperLowerShelfStateEnum.values();
for (UpperLowerShelfStateEnum e : values) {
if (e.getValue().equals(code)) {
return e;
}
}
return null;
}
}
注：本文中向数据库中保存得是枚举中value 值 如果需要 可自行修改