Can you build the array as an object before writing it, rather than bothering with all the individual pieces?

CopyObjectMapper mapper = new ObjectMapper();
ArrayNode array = mapper.createArrayNode();

int i = 0;
while (i < 6) {
    array.add(mapper.createArrayNode().add("" + i++).add("" + i++));
}
System.out.println(array);

Results in:

Copy[["0","1"],["2","3"],["4","5"]]

If you're not dealing with several megabytes of data or very tight memory constraints, this might turn out to be more maintainable as well.

I finally got it:

ObjectMapper objectMapper = new ObjectMapper();
TypeFactory typeFactory = objectMapper.getTypeFactory();
List<SomeClass> someClassList = objectMapper.readValue(jsonString, typeFactory.constructCollectionType(List.class, SomeClass.class));

http://www.baeldung.com/jackson-inheritance

You'll need to have those types inherit from one base class though.

Also; that is really bad JSON.

Yes, the Jackson manual parser design is quite different from other libraries. In particular, you will notice that JsonNode has most of the functions that you would typically associate with array nodes from other APIs. As such, you do not need to cast to an ArrayNode to use. Here's an example:

JSON:

{
    "objects" : ["One", "Two", "Three"]
}

Code:

final String json = "{\"objects\" : [\"One\", \"Two\", \"Three\"]}";

final JsonNode arrNode = new ObjectMapper().readTree(json).get("objects");
if (arrNode.isArray()) {
    for (final JsonNode objNode : arrNode) {
        System.out.println(objNode);
    }
}

Output:

"One"
"Two"
"Three"

Note the use of isArray to verify that the node is actually an array before iterating. The check is not necessary if you are absolutely confident in your data structure, but it's available should you need it (and this is no different from most other JSON libraries).

The problem is not in your code but in your json:

{"Compemployes":[{"id":1001,"name":"jhon"}, {"id":1002,"name":"jhon"}]}

this represents an object which contains a property Compemployes which is a list of Employee. In that case you should create that object like:

class EmployeList{
    private List<Employe> compemployes;
    (with getter an setter)
}

and to deserialize the json simply do:

EmployeList employeList = mapper.readValue(jsonString,EmployeList.class);

If your json should directly represent a list of employees it should look like:

[{"id":1001,"name":"jhon"}, {"id":1002,"name":"jhon"}]

Last remark:

List<Employee> list2 = mapper.readValue(jsonString, 
TypeFactory.collectionType(List.class, Employee.class));

TypeFactory.collectionType is deprecated you should now use something like:

List<Employee> list = mapper.readValue(jsonString,
TypeFactory.defaultInstance().constructCollectionType(List.class,  
   Employee.class));