Saving Data

Best way of saving / loading (reading) hashmaps?

 

Search for "SLAPI" in the Plugin Tutorial

 

On

Code:

list = SLAPI.load("example.bin");

Where it says "example.bin"
I understand that but are you suppose to manually create the topic and sub topics from the plugin? Because how else would you manually edit a .bin?

 

It is a binary file, get a hex editor if you don't want to do it from code. else move to a text based system such as yaml files with the configuration api

 

I'm getting errors about creating the data.bin file on start up?

 

That's nice. Feel free to tell the world what error you are getting.

 

Chances are, the data you're trying to save is best saved in the already existing YML config for your plugin. You can save a HashMap with the normal Configuration.set() method, and read it back again with Configuration.getValues().

Here's a good guide to the bukkit config system, if you're not familiar:
http://forums.bukkit.org/threads/tu...ration-api-create-a-yaml-configuration.42775/

 

It's quite easy once you understand how to do it.
First, you want to open a FileWriter or BufferedWriter on the file you want to write to.

Code:

try
{
    File file = new File(getDataFolder(), "data.txt");//This is the file you want to write to
    if(!file.exists())//If the file doesn't exist, make the file
    {
        FileOutputStream fos = new FileOutputStream(file);//Open a new FileOutputStream
        fos.flush();//Save the empty file
        fos.close();//Close the stream
    }
    BufferedWriter bw = new BufferedWriter(new FileWriter(file));//Open a new writer on the file
    for(Map.Entry<String, String> e:yourMap.entrySet())//This is assuming your map is <String, String>
    //It'll be easy if your keys and values are Strings and numbers
    {
        bw.write(e.getKey() + "," + e.getValue());//This will save the data
        //If your key was "a" and your value was "b" it would be saved as "a,b"
        bw.newLine();//Make a new line
    }
    bw.flush();//Save the data
    bw.close();//Close the writer
}
catch(IOException ioe)//An error occurred, oh no!
{
    ioe.printStackTrace();//Print the error log to the console
}

Next is loading, which can be done by opening a BufferedReader and parsing the lines.

Code:

try
{
    File file = new File(getDataFolder(), "data.txt");//This is the file you want to read from
    if(file.exists())//Your file exists!
    {
        BufferedReader br = new BufferedReader(new FileReader(file));//Create the reader
        String l;//This is the line that the reader will get while reading the file
        while((l = br.readLine() != null)//While the read line is not null
        {
            String[] tokens = l.split(",", 2);//Split the line by a comma, but limit the pieces to 2
            //This means "key,"value"" would be read as key and "value"
            if(tokens.length != 2)continue;//If there is only a key or only a value, skip the line
            yourMap.put(tokens[0], tokens[1]);//Store the data in your map
        }
        br.close();//Close the reader
    }
}
catch(IOException ioe)//An error occurred
{
    ioe.printStackTrace();//Print the error log to the console
}

Hope that helped!

 

I'm getting errors on reading the data.

My HashMaps are <String, Integer > 's and there are three of them so how do I differ from them and overwrite each other but only the same ones.. also here is my code error.

Code:

Type mismatch: cannot convert from boolean to String

Code:java

 
 
while((l = br.readLine() != null)
 
 

and

Code:

The method put(String, Integer) in the type HashMap<String,Integer> is not applicable for the arguments (String, String)

Code:java

 
           CCMage.MAGE_LIST.put(tokens[0], tokens[1]);
 

I'm sorry if I didn't explain my problems thoroughly or as in depth as possible, this whole matter is quite confusing to me.

 

I think the main complaint here is you're saying "I'm getting errors" but you're not posting the actual stacktrace (error) here. It's very hard to troubleshoot without it as often times the error tells you exactly where the problem lays.

 

These are not errors with saving data. These are type errors when you give a method a parameter of the wrong type. They seem to stem from syntax errors

 

Well I've actually gotten it figured out now, I have this:

Code:java

 
/**
* SLAPI = Saving/Loading API API for Saving and Loading Objects. You can
* use this API in your projects, but please credit the original author of
* it.
* 
* @author Tomsik68<[email][email protected][/email]>
*/
public static <T extends Object> void save(T obj, String path) throws Exception {
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(path));
oos.writeObject(obj);
oos.flush();
oos.close();
}
 
public static <T extends Object> T load(String path) throws Exception {
ObjectInputStream ois = new ObjectInputStream(new FileInputStream(path));
@SuppressWarnings("unchecked")
T result = (T) ois.readObject();
ois.close();
return result;
}
 
public static void saveData() {
File f = new File(CCMain.getInstance().getDataFolder(), "data.bin");
 
try {
if (!f.exists()) {
CCMain.getInstance().getDataFolder().mkdirs();
f.createNewFile();
}
save(CCMage.MAGE_LIST, "plugins/ClassCraft/data.bin");
save(CCPriest.PRIEST_LIST, "plugins/ClassCraft/data.bin");
save(CCWarrior.WARRIOR_LIST, "plugins/ClassCraft/data.bin");
} catch (Exception e) {
e.printStackTrace();
}
}
 
public static void loadData() {
File f = new File(CCMain.getInstance().getDataFolder(), "data.bin");
 
try {
if (!f.exists()) {
return;
}
CCMage.MAGE_LIST = load("plugins/ClassCraft/data.bin");
CCPriest.PRIEST_LIST = load("plugins/ClassCraft/data.bin");
CCWarrior.WARRIOR_LIST = load("plugins/ClassCraft/data.bin");
} catch (Exception e) {
e.printStackTrace();
}
}
 

However how do I make it save multiple Hashmaps? And allow each hashmap to overwrite itself.

 

SLAPI as it is written here, allows you to write one object per a file. Either encapsulate all your hashmaps into one object or write each hashmap into its own file, or rewrite parts of slapi to allow you to save multiple objects per file.

 

I always had trouble saving hashmaps as .bin files but maybe it was the types I was trying to save.
Saving them as .dat files worked great for me.

 

file endings mean nothing to Java, i can give my yaml file .baz or .ser and it would read it quite happily.

 

oh I see.. when I tried saving it as a .bin I always got errors, but maybe it was just a coincidence. :\

 

Okay then can you help me out man ha? How can I go about writing multiple hashmaps, and other forms of data into one file?

 

If you are going to use slapi, then encapsulate all the data you want to save within one serializable object. If not the Configuration API is more than capable of storing multiple Hashmaps and ConfigurationSerializable objects.

 

Okay and where is some documentation on the Configuration API so I may learn it?

 

The same place as all the other official documentaion. The Wiki and The Javadoc

 

Isn't the coniguration API like for a config ha? I mean it's not for saving data is it?

 

I also call my fish, 'egg tart'. But that does not mean I can eat it like one.

 

Weird;/

my code (open) my code (close)

Code:

package me.shaquu;
 
import org.bukkit.ChatColor;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.block.Block;
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.World;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.block.BlockPlaceEvent;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.java.JavaPlugin;
import me.shaquu.SerializableLocation;
import java.io.*;
import java.util.logging.Logger;
import java.io.PrintWriter;
 
public class TerrainS  extends JavaPlugin {
   
    public void onEnable(){;
        final Logger logger = getLogger();
        logger.info("-----TerrainS Activated!!!-----");
        FileConfiguration config = getConfig();
        config.addDefault("Path.subpath", "String");
        config.options().copyDefaults(true);
        saveConfig();
    }
 
    @EventHandler
    public void onBlockClick(BlockPlaceEvent event) {
        Player player = event.getPlayer();
        Block block = event.getBlockPlaced();
        int data = block.getTypeId();
        Location location = block.getLocation();
        int x = block.getX();
        int y = block.getY();
        int z = block.getZ();
   
        File dane = new File(getDataFolder(), "config.yml");
        String l = (new SerializableLocation(location)).toString();
        FileConfiguration config = getConfig();
        config.addDefault("Example.config","Happy?");
        config.options().copyDefaults(true);
        saveConfig();
       
     
        public static <T extends Object> void save(T obj, String path) throws Exception {
        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(path));
        oos.writeObject(obj);
        oos.flush();
        oos.close();
        }
       
        public static <T extends Object> T load(String path) throws Exception {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream(path));
        @SuppressWarnings("unchecked")
        T result = (T) ois.readObject();
        ois.close();
        return result;
        }
       
        public static void saveData() {
        File f = new File(CCMain.getInstance().getDataFolder(), "data.bin");
       
        try {
        if (!f.exists()) {
        CCMain.getInstance().getDataFolder().mkdirs();
        f.createNewFile();
        }
        save(x, "plugins/TerrainS/data.bin");
        save(y, "plugins/TerrainS/data.bin");
        save(z, "plugins/TerrainS/data.bin");
        save(data, "plugins/TerrainS/data.bin");
        } catch (Exception e) {
        e.printStackTrace();
        }
        }
       
        public static void loadData() {
        File f = new File(CCMain.getInstance().getDataFolder(), "data.bin");
       
        try {
        if (!f.exists()) {
        return;
        }
        save(x, "plugins/TerrainS/data.bin");
        save(y, "plugins/TerrainS/data.bin");
        save(z, "plugins/TerrainS/data.bin");
        save(data, "plugins/TerrainS/data.bin");
        } catch (Exception e) {
        e.printStackTrace();
        }
        }
   
       
       
 
   
        try{
            FileWriter fstream = new FileWriter("config.yml");
            BufferedWriter out = new BufferedWriter(fstream);
            out.write(x+" "+y+" "+z+" "+data);
            out.close();
          }catch (Exception e){
            System.err.println("Error: " + e.getMessage());
          }
    }
}
 

Now it's little messy
What I want to do?
Get a location(x,y,z) and type of placed block and save it to the file.
And save every block data(like upper) in the next line.
Help... I'm working on it very long time and I'm terrified;(

 

So how would I use the Configuration API to save to another file?

 

If you mean another yaml file, then keep reading the wiki page.

TGF
Here is a sample plugin that saves the information for a location in a separate yaml file.
https://github.com/SagaciousZed/SampleHome

 

and what if I mean another file type like a binary file?

 

Then you must implement FileConfiguration yourself. Much like how YamlConfiguration implements FileConfiguration.

 

I

It look very simple Thanks!
I will change it to my situation later^^

 

Well FFS could you possibly give me a little push and help me out with some code.. anything at all?

 

Here is something

Code:

 public class BinaryConfiguration extends FileConfiguration {
   ...
}