I feel like this is a simple problem, but none of the things i tried work for me. I have an enum, the reason i have string constructor is because Java doesn't allow enum to be numerical..I tried AA, AB, 2C directly without string constructor but that gives an error. Note that for the existing enum i am adding C("2C").

public enum TestEnum{

AA("AA"), AB("AB"), C("2C");

private String display;

private TestEnum( String display ) {

this.display = display;

}

public String toString() {

return display;

}

public String getDisplay() {

return display;

}

public void setDisplay( String display ) {

this.display = display;

}

public String getName() {

return display;

}

Now i have a mybatis mapper which does a merge this is existing and one of the param to the mapper is TestEnum. Until now this worked fine since enum value and string value are same, but i added C("2C"). Now i want to insert 2C to the table using mybaits, but it always inserts C.

merge into text t

using (select #{id} as id from dual) d on (d.id = t.id)

when matched then

update set

appId = #{applId},

src = #{testEnum}

testEnum inserts C, so i changed that to #{testEnum.toString()} which gave me a there is no getter for property name toString() error. I tried #{testEnum.display} and #{testEnum.name} both of them still inserts C whereas i want it to insert 2C. Do you guys know an easier way of handling this?

I don't want to change the model object to pass String rather than TestEnum because this object is being used in many places.Is there a way this can be done in the mybatis mapper without changing model object?

Thanks for your help :)

解决方案

What you need is a TypeHandler

First, add a static method to your TestEnum to return a TestEnum given a display string:

public static TestEnum fromDisplay(String display){

for (TestEnum v : TestEnum.values()){

if (v.getDisplay().equals(display)){

return v;

}

}

return null;

}

Then use it to create your TypeHandler:

import java.sql.CallableStatement;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import org.apache.ibatis.type.BaseTypeHandler;

import org.apache.ibatis.type.JdbcType;

public class TestEnumTypeHandler extends BaseTypeHandler {

@Override

public void setNonNullParameter(PreparedStatement ps, int i, TestEnum parameter, JdbcType jdbcType)

throws SQLException {

ps.setString(i, parameter.getDisplay());

}

@Override

public TestEnum getNullableResult(ResultSet rs, String columnName) throws SQLException {

return TestEnum.fromDisplay(rs.getString(columnName));

}

@Override

public TestEnum getNullableResult(ResultSet rs, int columnIndex) throws SQLException {

return TestEnum.fromDisplay(rs.getString(columnIndex));

}

@Override

public TestEnum getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {

return TestEnum.fromDisplay(cs.getString(columnIndex));

}

}

Finally, register your TypeHandler in your mybatis xml: