Fix hessian2 serialized short, byte is converted to int bug

[zonghaishang]

Fix hessian2 serialized short, byte is converted to int bug

for example:
if we test deserialize mode 'Hessian2StringShortType'
`
public class Hessian2StringShortType implements Serializable {

Map<String, Short> stringShortMap;

Map<String, Byte> stringByteMap;

Map<String, PersonType> stringPersonTypeMap;

public Hessian2StringShortType(){

}

}

public class PersonType implements Serializable {

String name;
int age;
double money;
short p1;
byte  p2;
List<Short> p3;

public PersonType(String name, int age, double money, short p1, byte p2, List<Short> p3) {
    this.name = name;
    this.age = age;
    this.money = money;
    this.p1 = p1;
    this.p2 = p2;
    this.p3 = p3;
}

@Override
public boolean equals(Object o) {
    if (this == o)
        return true;
    if (o == null || getClass() != o.getClass())
        return false;
    PersonType type = (PersonType) o;
    return age == type.age &&
        Double.compare(type.money, money) == 0 &&
        p1 == type.p1 &&
        p2 == type.p2 &&
        Objects.equals(name, type.name) &&
        Objects.equals(p3, type.p3);
}

@Override
public int hashCode() {
    return Objects.hash(name, age, money, p1, p2, p3);
}

}

@test
public void serialize_string_short_map_then_deserialize() throws Exception {

    Hessian2StringShortType stringShort = new Hessian2StringShortType();
    Map<String, Short> stringShortMap = new HashMap<String, Short>();
    stringShortMap.put("first", (short)0);
    stringShortMap.put("last", (short)60);
    stringShort.stringShortMap = stringShortMap;

    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    Hessian2Output out = new Hessian2Output(bout);

    out.writeObject(stringShort);
    out.flush();

    ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
    Hessian2Input input = new Hessian2Input(bin);

    Hessian2StringShortType deserialize = (Hessian2StringShortType) input.readObject();
    assertTrue(deserialize.stringShortMap != null);
    assertTrue(deserialize.stringShortMap.size() == 2);
    // however, the deserialize result is Integer !!!
    assertTrue(deserialize.stringShortMap.get("last") instanceof Short);
    assertEquals(Short.valueOf((short)0), deserialize.stringShortMap.get("first"));
    assertEquals(Short.valueOf((short)60), deserialize.stringShortMap.get("last"));
}

`
When we test serialize and deserialize 'Hessian2StringShortType', because it contains short、byte,
the property stringShortMap will be deserialized Map<String, Integer>, not Map<String, Short>!!!

More detail unit test can see: com.alibaba.com.caucho.hessian.io.Hessian2StringShortTest

The problem has been fixed in the current branch, please verify and merge, Thank you.
Here is my email: shangzonghai@youzan.com or jason.shang@hotmail.com

[codecov-io]

Codecov Report

Merging #1232 into master will increase coverage by 0.5%.
The diff coverage is 43.62%.

@@            Coverage Diff            @@
##           master    #1232     +/-   ##
=========================================
+ Coverage   31.78%   32.29%   +0.5%     
=========================================
  Files         689      689             
  Lines       34454    34561    +107     
  Branches     6799     6848     +49     
=========================================
+ Hits        10950    11160    +210     
+ Misses      21591    21466    -125     
- Partials     1913     1935     +22

Impacted Files	Coverage Δ
...ba/com/caucho/hessian/io/AbstractHessianInput.java	7.69% <0%> (-1.4%)	⬇️
...ibaba/com/caucho/hessian/io/SerializerFactory.java	59.43% <0%> (+4.43%)	⬆️
...ba/com/caucho/hessian/io/AbstractDeserializer.java	11.76% <20%> (+6.5%)	⬆️
...m/alibaba/com/caucho/hessian/io/Hessian2Input.java	17.94% <23.25%> (+2.18%)	⬆️
.../com/caucho/hessian/io/CollectionDeserializer.java	32.6% <25%> (+21.49%)	⬆️
...libaba/com/caucho/hessian/io/JavaDeserializer.java	53.1% <64.4%> (+16.89%)	⬆️
...alibaba/com/caucho/hessian/io/MapDeserializer.java	49.12% <91.66%> (+49.12%)	⬆️
...om/alibaba/dubbo/rpc/filter/ActiveLimitFilter.java	77.77% <0%> (-5.56%)	⬇️
...a/dubbo/remoting/transport/netty/NettyChannel.java	57.5% <0%> (-3.75%)	⬇️
.../com/alibaba/dubbo/monitor/dubbo/DubboMonitor.java	73.14% <0%> (-2.78%)	⬇️
... and 14 more

---

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[chickenlj]

@lovepoem Do you have time to review this PR? I've seen you fixed bugs in hessian before, you must be familiar with hessian code.

[lovepoem]

ok I will review this PR

[zonghaishang]

@lovepoem Do you have any question about this pr ?

[lovepoem]

This PR will be merged to 2.5.x at first. please merge 2.5.x to you pr. Then please check the hessian-lite/src/test/java/com/alibaba/com/caucho/hessian/io/PersonType.java , these is a JDK version adaptation assue @zonghaishang

[lovepoem]

Objects is a java8+ feature. please adapt the lower version

[zonghaishang]

I‘m using Objects.hash is java7+ feature, must adapt jdk1.6 ?

[zonghaishang]

@chickenlj @lovepoem please help review code, thanks.

[takeseem]

#1232
@lovepoem @zonghaishang
the add method will work in Hessian2Input, but in HessianInput not unsupported.
I think the HessianInput need to change to support the new methods.

[takeseem]

HessianInput.readObject(Class, Class[]) nosupported, effect #1608