要編寫可復(fù)用的MyBatis TypeHandler,可以遵循以下步驟:
public class MyTypeHandler implements TypeHandler<MyType> {
@Override
public void setParameter(PreparedStatement ps, int i, MyType parameter, JdbcType jdbcType) throws SQLException {
// 設(shè)置參數(shù)
}
@Override
public MyType getResult(ResultSet rs, String columnName) throws SQLException {
// 從結(jié)果集中獲取數(shù)據(jù)并轉(zhuǎn)換為Java對(duì)象
}
@Override
public MyType getResult(ResultSet rs, int columnIndex) throws SQLException {
// 從結(jié)果集中獲取數(shù)據(jù)并轉(zhuǎn)換為Java對(duì)象
}
@Override
public MyType getResult(CallableStatement cs, int columnIndex) throws SQLException {
// 從存儲(chǔ)過程的調(diào)用結(jié)果中獲取數(shù)據(jù)并轉(zhuǎn)換為Java對(duì)象
}
}
全局注冊(cè)示例:
<typeHandlers>
<typeHandler handler="com.example.MyTypeHandler"/>
</typeHandlers>
局部注冊(cè)示例:
<resultMap id="myResultMap" type="com.example.MyClass">
<id property="id" column="id" javaType="int" typeHandler="com.example.MyTypeHandler"/>
</resultMap>
public abstract class AbstractTypeHandler<T> implements TypeHandler<T> {
@Override
public void setParameter(PreparedStatement ps, int i, T parameter, JdbcType jdbcType) throws SQLException {
// 設(shè)置參數(shù)的通用邏輯
}
@Override
public T getResult(ResultSet rs, String columnName) throws SQLException {
// 獲取結(jié)果的通用邏輯
}
@Override
public T getResult(ResultSet rs, int columnIndex) throws SQLException {
// 獲取結(jié)果的通用邏輯
}
@Override
public T getResult(CallableStatement cs, int columnIndex) throws SQLException {
// 獲取結(jié)果的通用邏輯
}
}
通過以上步驟,可以編寫出可復(fù)用的MyBatis TypeHandler,實(shí)現(xiàn)Java對(duì)象和數(shù)據(jù)庫(kù)字段的靈活轉(zhuǎn)換,提高代碼的可維護(hù)性和可重用性。