I am trying to insert a new record into a simple database table with MyBatis but I get a strange exception. Mybe it is related to that I am not using POJO.
MyBatis version: 3.4.5
My table:
CREATE TABLE IF NOT EXISTS image
(
id BIGINT PRIMARY KEY,
content BYTEA
) WITHOUT OIDS;
MyBatis mapper:
@Insert("INSERT INTO image (id, content) VALUES (#{id}, #{content})")
@SelectKey(statement = "SELECT NEXTVAL('image_seq')", keyProperty = "id", before = true, resultType = long.class)
long insertImage(byte[] content);
The way I am trying to use it:
byte[] fileContent = IOUtils.toByteArray(inputStream);
long id = imageDao.insertImage(fileContent);
The exception what I get:
java.lang.ClassCastException: java.lang.Long cannot be cast to [B
at org.apache.ibatis.type.ByteArrayTypeHandler.setNonNullParameter(ByteArrayTypeHandler.java:26)
at org.apache.ibatis.type.BaseTypeHandler.setParameter(BaseTypeHandler.java:53)
at org.apache.ibatis.scripting.defaults.DefaultParameterHandler.setParameters(DefaultParameterHandler.java:87)
at org.apache.ibatis.executor.statement.PreparedStatementHandler.parameterize(PreparedStatementHandler.java:93)
at org.apache.ibatis.executor.statement.RoutingStatementHandler.parameterize(RoutingStatementHandler.java:64)
at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:86)
at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:49)
at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117)
at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76)
at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:198)
at org.apache.ibatis.session.defaults.DefaultSqlSession.insert(DefaultSqlSession.java:185)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
...
I do not want to create POJO class with getter/setter method for this one "content" param but I think this issue is related to missing POJO.
What is the solution?
EDIT
I am trying to debug mybatis code and I have found " [B
" in the parameterTypes
:
java.lang.Long cannot be cast to [B
This is saying that you are trying to convert long
to byte[]
Looking at source of org.apache.ibatis.type.ByteArrayTypeHandler
:
public void setNonNullParameter(PreparedStatement ps, int i, byte[] parameter, JdbcType jdbcType) throws SQLException {
ps.setBytes(i, parameter);
}
I think you need to remove {id}
from insert annotation (as this value is autogenerated).
@Insert("INSERT INTO image (content) VALUES (#{content})")
Otherwise parameters are shifted by one.
@SelectKey
is useful when you want to reuse generated value farther in the code, but it seems yo will not.
Then why not keep everything in the SQL:
INSERT INTO image (id, content) VALUES ((SELECT NEXTVAL('image_seq')), #{content})
For exception regarding parameters, parameters must be named with @Param
annotation
int insertImage(@Param("content") byte[] content);
or
int insertImage(@Param("id) Long id, @Param("content") byte[] content)
Note that INSERT as well as UPDATE and DELETE statements returns type int being the number of inserted/updated/deleted rows, [...]
EDIT: unless you consider that under the hood, the java 8 PreparedStatement.executeLargeUpdate
returning long is executed.
[...] and not the generated key as it is suggested. Then it seems you eventually want to get the key value, that means back to square one with @SelectKey
and need for a POJO and a target property for the generated value. It even works with bulk insert with generated keys.
I have discovered lately that actual parameters name can be used (then your code will work as is) if following instructions in settings section of the documentation :
useActualParamName
Allow referencing statement parameters by their actual names declared in the method signature. To use this feature, your project must be compiled in Java 8 with -parameters option . (Since: 3.4.1) valid values:true
|false
default:true
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