java.io
A node implement of "java.io.InputObjectStream.readObject()" and "java.io.OutputObjectStream.writeObject()".
Protocol
- Object Serialization Stream Protocol (A protocal is not all, still need to refer to the implementation.)
- Object Serialization Stream Protocol Mind Node
Install
$ npm install java.io --saveUsage
1. readObject()
var fs = require('fs');
var io = require('java.io');
var InputObjectStream = io.InputObjectStream;
var OutputObjectStream = io.OutputObjectStream;
// Read object and return whole info
var buf = fs.readFileSync('./test/fixtures/out/int/1024.bin');
var in = new InputObjectStream(buf, true);
var obj = in.readObject();
// Read object but return value only
var buf2 = fs.readFileSync('./test/fixtures/out/int/1024.bin');
var in2 = new InputObjectStream(buf);
var obj2 = in.readObject();obj should be:
{
'$' : {
value : 1024
},
'$class' : {
name : 'java.lang.Integer',
serialVersionUID : '1360826667806852920',
flags : 2,
fields : [{
type : 'I',
name : 'value'
}],
superClass : {
name : 'java.lang.Number',
serialVersionUID : '-8742448824652078965',
flags : 2,
fields : [],
superClass : null
}
}
}obj2 should be:
1024if you only care about the first object from input stream, you could write the code briefly:
var buf3 = fs.readFileSync('./test/fixtures/out/map/boolean.bin');
var obj3 = InputObjectStream.readObject(buf);then obj3 should be:
{ 'true': true, 'false': false }2. writeObject(obj)
var outputObjectStream = new OutputObjectStream();
// 1. Passed in argument must contains the whole info
// 2. Every time calling the writeObject function
// will return the buf had written in
var buf = outputObjectStream.writeObject(obj);A brief style is also OK:
OutputObjectStream.writeObject(obj);3. OutputObjectStream.normalize(obj, type)
A convenient way to convert ordinary JavaScript object to object of standard format with whole info.
- params
- obj: accept all primitive value or primitive array and map
- type: string | boolean | int | short | long | char | byte | float | double |
- return: normalized object
var outputObjectStream = new OutputObjectStream();
var normalizedObj = OutputObjectStream.normalize(true);
var buf = outputObjectStream.writeObject(normalizedObj);normalize(null)
normalize('string')
normalize(true)
normalize(1) // quals to normalize(1, 'int')
normalize(-123456, long)
normalize([ true, false, false, false ], 'boolean')
normalize( {'true': true, 'false': false}, 'boolean')4. addObject()
If a class has writeObject/readObject methods, you need to implement the corresponding methods, and add them via addObject() before read or write the object.
var io = require('java.io');
io.addObject({{className}}, {{class}});Builtin classes:
- java.util.ArrayList
- java.util.LinkedList
- java.util.HashMap
- java.util.HashSet
- java.util.TreeMap
- java.util.TreeSet
- java.util.Date
Data structure
{
// if a object has it's own readObject/writeObject method
// save it's special value here
'_$': ...,
// value of object
'$': ...,
// class description
'$class': {
name: 'className',
serialVersionUID: 'SVUID',
flags: flags,
fields:
[ { type: 'F', name: 'primitiveProperty' },
{ type: 'L', name: 'objProperty', classname: 'Ljava/lang/String;' }],
superClass: parentClassDescriptionOrNull
}
}Incompatible between 1.x and 2.x
- decode java
[Btonew Buffer([1, 2, 3])not[1, 2, 3]#10