Commit e75eadf4 authored by Schudel, MJ (Michel)'s avatar Schudel, MJ (Michel)

Initial commit

parents
.gradle
/build/
!gradle/wrapper/gradle-wrapper.jar
### STS ###
.apt_generated
.classpath
.factorypath
.project
.settings
.springBeans
### IntelliJ IDEA ###
.idea
*.iws
*.iml
*.ipr
### NetBeans ###
nbproject/private/
build/
nbbuild/
dist/
nbdist/
.nb-gradle/
\ No newline at end of file
buildscript {
ext {
springBootVersion = '1.5.9.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
}
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
group = 'nl.craftsmen.blockchain'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
repositories {
mavenCentral()
}
dependencies {
compile('org.springframework.boot:spring-boot-starter-web')
compile 'commons-codec:commons-codec:1.10'
testCompile('org.springframework.boot:spring-boot-starter-test')
}
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
distributionUrl=https\://services.gradle.org/distributions/gradle-3.5.1-bin.zip
#!/usr/bin/env sh
##############################################################################
##
## Gradle start up script for UN*X
##
##############################################################################
# Attempt to set APP_HOME
# Resolve links: $0 may be a link
PRG="$0"
# Need this for relative symlinks.
while [ -h "$PRG" ] ; do
ls=`ls -ld "$PRG"`
link=`expr "$ls" : '.*-> \(.*\)$'`
if expr "$link" : '/.*' > /dev/null; then
PRG="$link"
else
PRG=`dirname "$PRG"`"/$link"
fi
done
SAVED="`pwd`"
cd "`dirname \"$PRG\"`/" >/dev/null
APP_HOME="`pwd -P`"
cd "$SAVED" >/dev/null
APP_NAME="Gradle"
APP_BASE_NAME=`basename "$0"`
# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
DEFAULT_JVM_OPTS=""
# Use the maximum available, or set MAX_FD != -1 to use that value.
MAX_FD="maximum"
warn ( ) {
echo "$*"
}
die ( ) {
echo
echo "$*"
echo
exit 1
}
# OS specific support (must be 'true' or 'false').
cygwin=false
msys=false
darwin=false
nonstop=false
case "`uname`" in
CYGWIN* )
cygwin=true
;;
Darwin* )
darwin=true
;;
MINGW* )
msys=true
;;
NONSTOP* )
nonstop=true
;;
esac
CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
# Determine the Java command to use to start the JVM.
if [ -n "$JAVA_HOME" ] ; then
if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
# IBM's JDK on AIX uses strange locations for the executables
JAVACMD="$JAVA_HOME/jre/sh/java"
else
JAVACMD="$JAVA_HOME/bin/java"
fi
if [ ! -x "$JAVACMD" ] ; then
die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
Please set the JAVA_HOME variable in your environment to match the
location of your Java installation."
fi
else
JAVACMD="java"
which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
Please set the JAVA_HOME variable in your environment to match the
location of your Java installation."
fi
# Increase the maximum file descriptors if we can.
if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
MAX_FD_LIMIT=`ulimit -H -n`
if [ $? -eq 0 ] ; then
if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
MAX_FD="$MAX_FD_LIMIT"
fi
ulimit -n $MAX_FD
if [ $? -ne 0 ] ; then
warn "Could not set maximum file descriptor limit: $MAX_FD"
fi
else
warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
fi
fi
# For Darwin, add options to specify how the application appears in the dock
if $darwin; then
GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
fi
# For Cygwin, switch paths to Windows format before running java
if $cygwin ; then
APP_HOME=`cygpath --path --mixed "$APP_HOME"`
CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
JAVACMD=`cygpath --unix "$JAVACMD"`
# We build the pattern for arguments to be converted via cygpath
ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
SEP=""
for dir in $ROOTDIRSRAW ; do
ROOTDIRS="$ROOTDIRS$SEP$dir"
SEP="|"
done
OURCYGPATTERN="(^($ROOTDIRS))"
# Add a user-defined pattern to the cygpath arguments
if [ "$GRADLE_CYGPATTERN" != "" ] ; then
OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
fi
# Now convert the arguments - kludge to limit ourselves to /bin/sh
i=0
for arg in "$@" ; do
CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option
if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition
eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
else
eval `echo args$i`="\"$arg\""
fi
i=$((i+1))
done
case $i in
(0) set -- ;;
(1) set -- "$args0" ;;
(2) set -- "$args0" "$args1" ;;
(3) set -- "$args0" "$args1" "$args2" ;;
(4) set -- "$args0" "$args1" "$args2" "$args3" ;;
(5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
(6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
(7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
(8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
(9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
esac
fi
# Escape application args
save ( ) {
for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
echo " "
}
APP_ARGS=$(save "$@")
# Collect all arguments for the java command, following the shell quoting and substitution rules
eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
cd "$(dirname "$0")"
fi
exec "$JAVACMD" "$@"
@if "%DEBUG%" == "" @echo off
@rem ##########################################################################
@rem
@rem Gradle startup script for Windows
@rem
@rem ##########################################################################
@rem Set local scope for the variables with windows NT shell
if "%OS%"=="Windows_NT" setlocal
set DIRNAME=%~dp0
if "%DIRNAME%" == "" set DIRNAME=.
set APP_BASE_NAME=%~n0
set APP_HOME=%DIRNAME%
@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
set DEFAULT_JVM_OPTS=
@rem Find java.exe
if defined JAVA_HOME goto findJavaFromJavaHome
set JAVA_EXE=java.exe
%JAVA_EXE% -version >NUL 2>&1
if "%ERRORLEVEL%" == "0" goto init
echo.
echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
echo.
echo Please set the JAVA_HOME variable in your environment to match the
echo location of your Java installation.
goto fail
:findJavaFromJavaHome
set JAVA_HOME=%JAVA_HOME:"=%
set JAVA_EXE=%JAVA_HOME%/bin/java.exe
if exist "%JAVA_EXE%" goto init
echo.
echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
echo.
echo Please set the JAVA_HOME variable in your environment to match the
echo location of your Java installation.
goto fail
:init
@rem Get command-line arguments, handling Windows variants
if not "%OS%" == "Windows_NT" goto win9xME_args
:win9xME_args
@rem Slurp the command line arguments.
set CMD_LINE_ARGS=
set _SKIP=2
:win9xME_args_slurp
if "x%~1" == "x" goto execute
set CMD_LINE_ARGS=%*
:execute
@rem Setup the command line
set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
@rem Execute Gradle
"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
:end
@rem End local scope for the variables with windows NT shell
if "%ERRORLEVEL%"=="0" goto mainEnd
:fail
rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
rem the _cmd.exe /c_ return code!
if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
exit /b 1
:mainEnd
if "%OS%"=="Windows_NT" endlocal
:omega
package nl.craftsmen.blockchain.blockchain;
import java.time.Instant;
import java.util.ArrayList;
import java.util.List;
public class Block {
private final long index;
private final long timestamp;
private final List<Transaction> transactions;
private final long proof;
private final String previousHash;
public Block(long index,long timestamp, List<Transaction> transactions, long proof, String previousHash) {
this.index = index;
this.timestamp = timestamp;
this.transactions = new ArrayList<>(transactions);
this.proof = proof;
this.previousHash = previousHash;
}
public long getIndex() {
return index;
}
public long getProof() {
return proof;
}
public long getTimestamp() {
return timestamp;
}
public List<Transaction> getTransactions() {
return transactions;
}
public String getPreviousHash() {
return previousHash;
}
}
package nl.craftsmen.blockchain.blockchain;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.codec.binary.Hex;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;
import javax.annotation.PostConstruct;
import java.math.BigDecimal;
import java.security.MessageDigest;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.time.Instant;
import java.util.*;
@Component
public class Blockchain {
private List<Block> chain = new ArrayList<>();
private List<Transaction> currentTransactions = new ArrayList<>();
private Set<String> nodes = new HashSet<>();
private RestTemplate restTemplate = new RestTemplate();
@PostConstruct
public void initFirstBlock() {
newBlock(100, "1");
}
private Block newBlock(long proof, String previousHash) {
Block block = new Block(getIndexOfLastBlock(), Instant.now().toEpochMilli(), currentTransactions, proof, previousHash);
chain.add(block);
currentTransactions.clear();
return block;
}
public List<Block> getBlockchain() {
return Collections.unmodifiableList(chain);
}
public long newTransaction(Transaction transaction) {
currentTransactions.add(transaction);
//notify the other nodes of this transaction
for (String node : nodes) {
restTemplate.postForEntity(node + "/newtransaction", transaction, Object.class);
}
return getIndexOfLastBlock();
}
public Block mine() {
long lastProof = getLastBlock().get().getProof();
long newProof = proofOfWork(lastProof);
//reward the miner
Transaction transaction = new Transaction("0", "this-node", BigDecimal.valueOf(1));
newTransaction(transaction);
String previousHash = hash(getLastBlock().get());
Block newBlock = newBlock(newProof, previousHash);
for (String node: nodes) {
restTemplate.postForEntity(node + "newblock", newBlock, null);
}
return newBlock;
}
private long getIndexOfLastBlock() {
Optional<Block> block = getLastBlock();
return block.map(block1 -> block1.getIndex() + 1).orElse(1L);
}
private Optional<Block> getLastBlock() {
return chain.size() == 0 ? Optional.empty() : Optional.of(chain.get(chain.size() - 1));
}
private long proofOfWork(long lastProof) {
/*Simple Proof of Work Algorithm:
- Find a number p' such that hash(pp') contains leading 4 zeroes, where p is the previous p'
- p is the previous proof, and p' is the new proof*/
long nr = 0;
String hash;
do {
hash = createHashAsHexString(lastProof + "" + nr);
nr++;
} while (!validProof(hash));
return nr;
}
private boolean validProof(String hash) {
return hash.startsWith("0000");
}
private String hash(Block block) {
try {
ObjectMapper mapper = new ObjectMapper();
String blockString = mapper.writeValueAsString(block);
return createHashAsHexString(blockString);
} catch (JsonProcessingException e) {
throw new RuntimeException(e);
}
}
private String createHashAsHexString(String blockString) {
try {
MessageDigest digest = MessageDigest.getInstance("SHA-256");
byte[] hash = digest.digest(blockString.getBytes());
return new String(Hex.encodeHex(hash));
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e);
}
}
public void registerNode(String address) {
nodes.add(address);
}
public boolean validChain(List<Block> chain) {
return true;
}
public void resolveConflicts() {
for (String node : nodes) {
List<Block> otherChain = restTemplate.getForObject(node + "blockchain", List.class);
if (otherChain.size() > chain.size() && validChain(otherChain)) {
this.chain = otherChain;
}
}
}
public void insertNewBlock(Block block) {
//mind you, no validation whatsoever is done here. Probably should check the validity of the received block.
chain.add(block);
}
}
package nl.craftsmen.blockchain.blockchain;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class BlockchainApplication {
public static void main(String[] args) {
SpringApplication.run(BlockchainApplication.class, args);
}
}
package nl.craftsmen.blockchain.blockchain;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController
public class BlockchainRestController {
@Autowired
private Blockchain blockchain;
@PostMapping("newtransaction")
public String newTransaction(@RequestBody Transaction transaction) {
long l = blockchain.newTransaction(transaction);
return "{\"message\": \"new transaction will be added to block " + l + "\"}";
}
@PostMapping("mine")
public Block mine() {
return blockchain.mine();
}
@PostMapping("registernode")
public void registerNode(@RequestBody List<String> addresses) {
addresses.forEach(blockchain::registerNode);
}
@GetMapping("blockchain")
public List<Block> blockchain() {
return blockchain.getBlockchain();
}
@PostMapping
public void newBlock(@RequestBody Block block) {
blockchain.insertNewBlock(block);
}
@GetMapping("resolve")
public void resolve() {
blockchain.resolveConflicts();
}
}
package nl.craftsmen.blockchain.blockchain;
import java.math.BigDecimal;
public class Transaction {
private String sender;
private String recepient;
private BigDecimal amount;
public Transaction() {
}
public Transaction(String sender, String recepient, BigDecimal amount) {
this.sender = sender;
this.recepient = recepient;
this.amount = amount;
}
public void setSender(String sender) {
this.sender = sender;
}
public void setRecepient(String recepient) {
this.recepient = recepient;
}
public void setAmount(BigDecimal amount) {
this.amount = amount;
}
public String getSender() {
return sender;
}
public String getRecepient() {
return recepient;
}
public BigDecimal getAmount() {
return amount;
}
}
package nl.craftsmen.blockchain.blockchain;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
@RunWith(SpringRunner.class)
@SpringBootTest
public class BlockchainApplicationTests {
@Test
public void contextLoads() {
}
}
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