Problem description

In the use of hibernate Splicing hql when , The new field does not appear in the construction method ( Here's a simplified version , The real situation is much more complicated )

// Entity class 
public class Tmd {
    
	private String CBh;
	private Integer NSjzzaqxx;
	//private String CAjysly;// Add a new field 
	public static final String cTmdConstructorFields = "(CBh,NSjzzaqxx)";
	//public static final String cTmdConstructorFields = "(CBh,NSjzzaqxx,CAjysly)";// Add new fields to the constructor 
	//......Constructos......
	//......getter/setter......
}



// Tool class 
public class DatamodelUtils{
    
	public static String CTmdConstructorFields = Tmd.cTmdConstructorFields;
}

adopt Hibernate Query object , Use here select new The way ,SQL How many parameters does the object in have , Entity classes should also have constructors with the same data type and number of parameters

StringBuilder hql = new StringBuilder();
hql.append("select new ").append("com.luo.Tmd").append(DatamodelUtils.CTmdConstructorFields);

This is what runs on the server , Because of the need , I am here Tmd Added a new field CAjysly, The constructor has also been modified , Finally, I put the revised Tmd.class The work put on the test environment is currently work in , Restart project , Report errors

Caused by: org.springframework.orm.hibernate3.HibernateQueryException: Unable to locate appropriate constructor on class .....

Read the log , Found no fields I added , The last one is hql That's true

select new com.luo.Tmd(CBh,NSjzzaqxx)

Why don't I add new fields ？

Cause analysis ：

After adding a field , The code is not compiled

Then I immediately go to the generation environment to check Tmd.class, See if I didn't compile , Subsequent use arthas Went to see Tmd.class, It is found that the new field exists , There are also... In the constructor , At this time, I am very confused

// Before modification DatamodelUtils.class
public static String CTmdConstructorFields = "(CBh,NSjzzaqxx)";

And then look at it DatamodelUtils.CTmdConstructorFields value , It turns out to be "(CBh,NSjzzaqxx)", It's still the original value , At this point, I probably understand , My replacement file is just Tmd.class, however DatamodelUtils.class It's still the same , Did not reload , Because the server didn't detect DatamodelUtils The change of

Solution ：

Yes DatamodelUtils Recompile , Publish to the test environment

Reflection summary ：

In the case of an incremental replacement file , Modification of constants , Remember where constants are used , Have to recompile , And then release