fix #210 JavaDeserializer._constructor.newInstance([null, null]) NPE

[takeseem]

this is an old issue #210

• I think if use constructor(null...) throw NPE then try use constructor(new Arg1(), new Arg2()) again to instance a bean, is a good idea.

• JavaDeserializer NPF for org.springframework.jdbc.UncategorizedSQLException

public UncategorizedSQLException(String task, @Nullable String sql, SQLException ex) {
	super(task + "; uncategorized SQLException" + (sql != null ? " for SQL [" + sql + "]" : "") +
			"; SQL state [" + ex.getSQLState() + "]; error code [" + ex.getErrorCode() + "]; " +
			ex.getMessage(), ex);
	this.sql = sql;
}

• the stacktrace like this:

com.alibaba.com.caucho.hessian.io.HessianProtocolException: 'org.springframework.jdbc.UncategorizedSQLException' could not be instantiated
	at com.alibaba.com.caucho.hessian.io.JavaDeserializer.instantiate(JavaDeserializer.java:313)
    ...
Caused by: java.lang.reflect.InvocationTargetException
	... 
Caused by: java.lang.NullPointerException
	at org.springframework.jdbc.UncategorizedSQLException.<init>(UncategorizedSQLException.java)
	...

[takeseem]

@lovepoem @zonghaishang
#1232 HessianInput.readObject(Class, Class[]) nosupported
因为我对Hessian不熟，#1232 需要覆盖测试Hessian1的，看代码#1232 只支持Hessian2

[zonghaishang]

@takeseem

1. constructor(null...) , This is the validation rule of the instance object itself.
2. HessianInput.readObject(Class, Class[]) not supported, there is no direct relationship between this exception and pr.

Please provide the full jar package that has this exception：

1. dubbo
2. org.springframework.jdbc.UncategorizedSQLException

thanks.

[takeseem]

@zonghaishang 但是用 #1232 提交之前的代码，是工作很好的。既然AbstracthessianInput增加了方法，为什么heassian2能兼容和heassian1就不支持？这本身会导致所有的hessian1协议在#1232之后不再得到支持。

当然我也可以如你所说，去掉hessian1的junit以保证测试用例ok。

HessianInput.inistant()方法本意是构造一个对象而已。但是类创建者不知道会传入一个null。

“Please provide the full jar package that has this exception：
dubbo
org.springframework.jdbc.UncategorizedSQLException”
你需要的信息如下：

• 我提交的代码就明确了依赖哪个dubbo
• 1楼UncategorizedSQLException本身链接spring的源码

[zonghaishang]

@takeseem

既然AbstracthessianInput增加了方法，为什么heassian2能兼容和heassian1就不支持？

1. The new abstract method I added did not implement in Hessian1 by default, you should not reuse my hessian2 unit test to verify hessian1.
2. Does it need to support hessian1, maybe I will support later today.
3. dubbo调用报错HessianFieldException #210 is inconsistent with the given line number, perhaps due to the version used by the spring-jdbc framework

[takeseem]

既然AbstracthessianInput增加了方法，为什么heassian2能兼容和heassian1就不支持？

1. The new abstract method I added did not implement in Hessian1 by default, you should not reuse my hessian2 unit test to verify hessian1.
   虽然是开源项目，假设客户已经在生产中使用hessian1，这对客户来说升级版本将是灾难。
   所以我说不严谨
2. Does it need to support hessian1, maybe I will support later today.
   点赞
3. dubbo调用报错HessianFieldException #210 is inconsistent with the given line number, perhaps due to the version used by the spring-jdbc framework
   我会根据git的show revision information找到有用的信息，但dubbo调用报错HessianFieldException #210 案例最新代码依然能定位并重现问题。

[zonghaishang]

@takeseem
Hessian1 protocol is not used in dubbo， but hessian1 protocol compatibility I have fixed, more detail see : #1616

[ralf0131]

Hi, please check the CI failure.

[diecui1202]

@takeseem After discussing with @zonghaishang For this question, you can implement custom Deserializer, and then register it to SerializerFactory, such as:

Deserializer des = new XXXDeserializer();

ExtSerializerFactory ext = new ExtSerializerFactory();
ext.addDeserializer(UncategorizedSQLException.class, des);

serializerFactory.addFactory(ext);

You can try it with this way.

[beiwei30]

@takeseem, hessian-lite is moved out into github/dubbo, pls. feel free to resubmit PR there, if you don't agree with @diecui1202's suggestion.