spring3 + mybatis自定義typeHandler

Question

我有一些類型為Set<String>字段的pojo。 我想將它們作為json持久保存在數據庫中，所以我創建了一個自定義的typeHandler，但是當我嘗試持久保存時出現錯誤：沒有找到TypeHandler...。

 testSave(it.infora.suap.service.MailMessageServiceTest): nested exception is org.apache.ibatis.executor.ExecutorException: There was no TypeHandler found for parameter recipients_to of statement it.infora.suap.persistence.MailMessageMapper.insertEmailMessage

Set<String>的參數receivers_to

這是我的自定義typeHandler類：

public class SetTypeHandler implements TypeHandler<Set<String>>{


    @Override
    public void setParameter(PreparedStatement ps, int columnIndex, Set<String> parameter, JdbcType jt) throws SQLException {
    ps.setString(columnIndex,  serializeToJson(parameter));
    }

    @Override
    public Set<String> getResult(ResultSet rs, String columnName) throws SQLException {
        return deserializeFromJson(rs.getString(columnName));
    }

    @Override
    public Set<String> getResult(ResultSet rs, int columnIndex) throws SQLException {
        return deserializeFromJson(rs.getString(columnIndex));
    }

    @Override
    public Set<String> getResult(CallableStatement cs, int columnIndex) throws SQLException {
        return deserializeFromJson(cs.getString(columnIndex));
    }

    private String serializeToJson(Set<String> parameter){
        Gson gson = new Gson();
        return gson.toJson(parameter);
    }

    private Set<String> deserializeFromJson(String value){
        Gson gson = new Gson();
        Type collectionType = new TypeToken<Set<String>>(){}.getType();
        Set<String> result  = gson.fromJson(value, collectionType);

        return result;       
    }

}

怎么了？ 我正在使用帶注釋的mapper接口而不是mapper.xml

謝謝

安德里亞

Answer 1

我在這里和這里找到了一些信息，但似乎您錯過了

@MappedTypes(Set.class) 
public class SetTypeHandler implements TypeHandler<Set<String>>{