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John Main

Code. Design. Hosting. Maintenance.

10
Sep '11

Store the system properties in an XML file

import java.io.*;
/**
* @param fileName the file to save the properties in
*/
public void storeSystemProperties(String fileName) {
try {
Properties prop = System.getProperties();
FileOutputStream fileOut = new FileOutputStream(new File(fileName));
prop.storeToXML(fileOut, "Properties");
fileOut.flush();
fileOut.close();
}
catch(FileNotFoundException e) {
System.out.println(e.getMessage());
}
catch(IOException e) {
System.out.println(e.getMessage());
}
}
27
Aug '11

Read a config file, parse it and add key/value pairs to a hashmap

import java.io.*;
import java.util.HashMap;
/**
* @param configFile the location of the configuration file
* @return the produced HashMap
*/
public HashMap importConfig(String configFile) {
HashMap config = new HashMap;
try {
BufferedReader bufRead = new BufferedReader(new FileReader(configFile));
while(bufRead.ready()) {
String line = bufRead.readLine();
if(!line.startsWith("#") && line.indexOf("=") != -1) {
//Trim out whitespace, explode at equals and put key/value pairs into the config HashMap
int splitPos = line.indexOf("=");
String key = line.substring(0, splitPos).trim();
String value = line.substring(splitPos+1, line.length()).trim();
if(!key.equals("") && !value.equals("")) {
config.put(key, value);
}
}
}
bufRead.close();
}
catch (FileNotFoundException e) {
System.out.println(e.getMessage());
}
catch (IOException e) {
System.out.println(e.getMessage());
}
return config;
}
01
Jul '11

Pass it a filename and it’ll pass you back the Hash. Simple as that!

import java.io.*;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public String getMD5Hash(String fileName) {
String hash = "";
try {
File file = new File(fileName);
FileReader fileRead = new FileReader(file);
MessageDigest md = MessageDigest.getInstance("MD5");
char[] chars = new char[1024];
int charsRead = 0;
do {
charsRead = fileRead.read(chars, 0, chars.length);
if(charsRead >= 0) {
md.update(new String(chars, 0, charsRead).getBytes());
}
}
while(charsRead >= 0);
hash = new BigInteger(1, md.digest()).toString(16);
}
catch (NoSuchAlgorithmException e){}
catch (IOException e){}
return hash;
}