# Java和Kotlin写合约的例子
# 使用Java编写合约的例子
// file Utils.java
import gjavac.lib.Component;
import static gjavac.lib.UvmCoreLibs.print;
@Component
public class Utils {
public int sum(int a, int b) {
print("this is util sum func");
return a + b;
}
}
// file Storage.java
public class Storage {
public String name; // both field and property supported
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
// file DemoContract1.java
import gjavac.lib.Contract;
import gjavac.lib.Offline;
import gjavac.lib.UvmContract;
import static gjavac.lib.UvmCoreLibs.*;
@Contract(storage = Storage.class)
class DemoContract extends UvmContract<Storage> {
@Override
public void init() {
print("init of demo java Contract");
this.getStorage().name = "my_contract";
print("storage.name changed to " + this.getStorage().getName());
pprint(this.getStorage());
}
public String sayHi(String name) {
print("say hi api called of contract to " + name);
return "Hello" + name;
}
public void setName(String name) {
this.getStorage().setName(name);
pprint("name changed to " + name);
}
public String getName(String arg) {
print("storage.name=" + this.getStorage().getName());
String name = this.getStorage().getName();
return name;
}
@Offline
public String offlineGetInfo(String arg) {
print("offlineGetInfo called with arg " + arg);
Utils utils = new Utils();
print("3+4=" + utils.sum(3, 4));
return "hello, offline api";
}
}
// file DemoContractEntrypoint.java
import gjavac.lib.UvmContract;
import static gjavac.lib.UvmCoreLibs.print;
public class DemoContractEntrypoint {
public UvmContract main() {
print("hello java");
DemoContract contract = new DemoContract();
contract.setStorage(new Storage());
print(contract);
contract.init();
return contract;
}
}
# 使用Kotlin写智能合约的例子
import gjavac.lib.*
class Storage {
var name: String? = null
// var age: Int? = null
}
@Component
class Utils {
fun sum(a: Int, b: Int): Int {
UvmCoreLibs.print("this is util sum func")
return a + b
}
}
@Contract(storage = Storage::class)
class MyContract : UvmContract<Storage>() {
override fun init() {
val a: Byte = 123
UvmCoreLibs.print("init of demo Contract " + a)
this.storage?.name = "my_contract" // TODO: getfield error in chain
UvmCoreLibs.print("storage.name changed")
UvmCoreLibs.pprint(this.storage)
UvmCoreLibs.print(this.storage?.name)
// this.storage?.age = 25 // FIXME: maybe crash
}
fun sayHi(name: String): String {
UvmCoreLibs.print("say hi api called of contract to $name")
return "Hello" + name
}
fun setName(name: String) {
this.storage?.name = name
UvmCoreLibs.pprint("name changed to " + name)
}
fun getName(arg: String) {
UvmCoreLibs.print("storage.name=" + this.storage?.name)
}
@Offline
fun offlineGetInfo(arg: String): String {
UvmCoreLibs.print("offlineGetInfo called with arg " + arg)
// testUtil() // FIXME: change to get this["testUtil"]()
val utils = Utils()
UvmCoreLibs.print("3+4=" + utils.sum(3, 4))
return "hello, offline api"
}
private fun testUtil() {
UvmCoreLibs.print("this is util func not in apis")
}
}
class Person {
// TODO: event, LCMP, LREM etc.
fun sayHi(name: String): String {
UvmCoreLibs.print("sayHi func called")
return "Hello$name java. I love money"
}
companion object {
//
// fun sum(a: String, b: String): String {
// return a + b
// }
}
fun testIf(): Boolean {
val a = 1
val b = 2
val c = 3
if(a<b) {
UvmCoreLibs.print("$a < $b")
}
if(c>=b) {
UvmCoreLibs.print("$c>=$b")
}
if(b>c) {
UvmCoreLibs.print("error here")
} else {
UvmCoreLibs.print("$b <= $c")
}
return true
}
fun testFor() {
UvmCoreLibs.print("testFor cases")
var sum = 0
// TODO
}
fun testWhile() {
UvmCoreLibs.print("testWhile cases")
var sum = 0
var i = 0
while(i<10) {
sum += i
i++
println(i)
}
UvmCoreLibs.print("sum=$sum")
var j = 100
var sum2 = 0
do {
sum2 += j
j--
}while(j>=0)
println("sum2=$sum2")
}
// fun testWhen() {
// println("testWhen cases")
// var i = 0
// while(i<4) {
// println(i)
// when(i) {
// 0 -> println("$i=0")
// 1->println("$i=1")
// 2->println("$i=2")
// else -> println("$i>2")
// }
// i++
// }
// }
// TODO: test continue, break
fun test_pprint() {
UvmCoreLibs.pprint(this)
}
fun testNumber() {
UvmCoreLibs.print("testNumber cases:")
val a = 4
val b = 5
val c = 1.23
val d = a + b
val e = a + c
val f = b*c
val h = c/b
UvmCoreLibs.print(c)
println("$a + $b = $d")
println("$a + $c = $e")
println("$b * $c = $f")
println("$c / $b = $h")
println("1 = ${UvmCoreLibs.tointeger(c)}")
println("~ ${a} = ${UvmCoreLibs.neg(a as Long)}")
}
fun testBooleans() {
var a = true
var b = false
var c = a && b
UvmCoreLibs.print("a && b=$c")
println("a || b=${a||b}")
if(a) {
UvmCoreLibs.print("$a=true")
}
if(b) {
UvmCoreLibs.print("error happend in boolean test")
} else {
UvmCoreLibs.print("$b=false")
}
var i=0
while(i<3) {
if(!(i>1)) {
UvmCoreLibs.print("!($i>1)=true")
}
i++
}
UvmCoreLibs.print("!c=${!c}")
}
fun testArray() {
UvmCoreLibs.print("testArray cases")
val array1 = UvmArray.create<Int?>()
array1.add(1)
array1.add(2)
array1.add(3)
array1.add(4)
UvmCoreLibs.pprint(array1)
UvmCoreLibs.print("array 1 size is " + array1.size()) // 4
array1.set(4, 2)
UvmCoreLibs.print("array[4] is " + array1.get(4)) // 2
array1.pop()
UvmCoreLibs.print("array 1 after changed size is " + array1.size()) // 3
UvmCoreLibs.print("array[3] is " + array1.get(3)) // 3
UvmCoreLibs.pprint(array1)
for (i in 1..(array1.size())) {
val item = array1.get(i)
UvmCoreLibs.print("index: " + i)
UvmCoreLibs.print("value: " + item)
}
val array1Iter = array1.ipairs()
var array1keyValuePair = array1Iter(array1, 0)
while (array1keyValuePair.first != null)
{
UvmCoreLibs.print("key: " + array1keyValuePair.first)
UvmCoreLibs.print("value: " + array1keyValuePair.second)
array1keyValuePair = array1Iter(array1, array1keyValuePair.first)
}
array1.set(3, null)
UvmCoreLibs.print("array1 size is ${array1.size()} after remove index 3")
UvmCoreLibs.pprint(array1)
}
fun testMap() {
val map1 = UvmMap.create<String>()
map1.set("name", "C#")
map1.set("country", "China")
UvmCoreLibs.print("map1's name is " + map1.get("name"))
UvmCoreLibs.print("map1's country is " + map1.get("country"))
// 遍历map的demo
val map1PairsIter = map1.pairs()
UvmCoreLibs.pprint(map1PairsIter)
var keyValuePair = map1PairsIter(map1, null)
UvmCoreLibs.pprint(keyValuePair)
UvmCoreLibs.print(keyValuePair.first)
UvmCoreLibs.print(keyValuePair.second)
while (keyValuePair.first != null)
{
UvmCoreLibs.print("key: " + UvmCoreLibs.tostring(keyValuePair.first))
UvmCoreLibs.print("value: " + UvmCoreLibs.tostring(keyValuePair.second))
// debug()
if (keyValuePair.first == "name")
{
UvmCoreLibs.print("found key==name pair")
}
keyValuePair = map1PairsIter(map1, keyValuePair.first)
}
val table1 = map1 as UvmTable
UvmCoreLibs.pprint("cast C#=" + (table1 as UvmMap<String>).get("name"))
}
fun testEvent() {
UvmCoreLibs.emit("Hello", "World") // FIXME: change to emitEventMethod
}
fun testModules() {
UvmCoreLibs.print("testModules cases")
val strModule = UvmCoreLibs.importModule(UvmStringModule::class.java, "string")
val len = strModule.len("Hello")
UvmCoreLibs.print("Hello length is $len")
var tableModule = UvmCoreLibs.importModule<UvmTableModule>(UvmTableModule::class.java, "table")
var table1 = UvmArray.create<String>()
table1.add("a")
tableModule.append(table1, "b")
var table1Count = tableModule.length(table1)
UvmCoreLibs.print("table1 size is: " + table1Count)
val mathModule = UvmCoreLibs.importModule<UvmMathModule>(UvmMathModule::class.java, "math")
val floor1 = mathModule.floor(3.3)
UvmCoreLibs.print("floor(3.3) = " + floor1)
val abs1 = mathModule.abs(-4)
UvmCoreLibs.print("abs(-4) = " + abs1)
val pi = mathModule.pi
UvmCoreLibs.print("pi = " + pi)
val stoi1 = mathModule.tointeger("123")
UvmCoreLibs.print("123=$stoi1")
var timeModule = UvmCoreLibs.importModule<UvmTimeModule>(UvmTimeModule::class.java, "time");
UvmCoreLibs.print("date: " + timeModule.tostr(1494301754))
val jsonModule = UvmCoreLibs.importModule<UvmJsonModule>(UvmJsonModule::class.java, "json");
UvmCoreLibs.print("dumps of json module is: " + jsonModule.dumps(jsonModule))
}
fun testImportContract() {
// TODO
val utilsContract = UvmCoreLibs.importContract(Utils::class.java, "utils")
UvmCoreLibs.print("3+4=${utilsContract.sum(3, 4)}")
}
fun main(): MyContract {
// entry point of contract
UvmCoreLibs.print("hello uvm")
val contract = MyContract()
// don't init contract when compile to gpc, used as contract
// if (contract is MyContract) {
// print("contract is contract")
// print(contract.sayHi("contract-name"))
// contract.storage = Storage()
// contract.init()
// print("name="+contract.storage?.name)
// val offlineApiRes = contract.offlineGetInfo("hi")
// print("offline api res is $offlineApiRes")
// }
testIf()
testNumber()
testWhile()
// testWhen()
test_pprint()
testBooleans()
testArray()
testMap()
testEvent()
testModules()
// testImportContract()
UvmCoreLibs.print(sayHi("hi-name"))
return contract
}
}
← gjavac 使用指南 汇编语言参考 →