IoUtils.java

package io.github.lucaseasedup.logit.util;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.StringWriter;
import java.net.URLDecoder;
import java.nio.channels.FileChannel;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

public final class IoUtils
{
    private IoUtils()
    {
    }
    
    public static String toString(InputStream is) throws IOException
    {
        if (is == null)
            throw new IllegalArgumentException();
        
        try (
                StringWriter sw = new StringWriter();
                InputStreamReader isr = new InputStreamReader(is);
        )
        {
            char[] buffer = new char[1024 * 4];
            int n;
            
            while ((n = isr.read(buffer)) != -1)
            {
                sw.write(buffer, 0, n);
            }
            
            return sw.toString();
        }
    }
    
    public static String toString(File file) throws IOException
    {
        if (file == null)
            throw new IllegalArgumentException();
        
        try (InputStream is = new FileInputStream(file))
        {
            return IoUtils.toString(is);
        }
    }
    
    public static void readResource(String resource, OutputStream out)
            throws IOException
    {
        if (resource == null || out == null)
            throw new IllegalArgumentException();
        
        int readBytes;
        byte[] buffer = new byte[1024 * 4];
        
        String jarUrlPath = IoUtils.class.getProtectionDomain()
                .getCodeSource().getLocation().getPath();
        String jarPath = URLDecoder.decode(jarUrlPath, "UTF-8");
        
        try (ZipFile jarZipFile = new ZipFile(jarPath))
        {
            ZipEntry entry = jarZipFile.getEntry(resource);
            
            if (entry != null)
            {
                try (InputStream is = jarZipFile.getInputStream(entry))
                {
                    while ((readBytes = is.read(buffer)) > 0)
                    {
                        out.write(buffer, 0, readBytes);
                    }
                }
            }
        }
    }
    
    public static void extractResource(String resource, File dest)
            throws IOException
    {
        if (resource == null || dest == null)
            throw new IllegalArgumentException();
        
        try (FileOutputStream fos = new FileOutputStream(dest))
        {
            readResource(resource, fos);
        }
    }
    
    public static String resourceToString(String resource)
            throws IOException
    {
        if (resource == null)
            throw new IllegalArgumentException();
        
        try (ByteArrayOutputStream baos = new ByteArrayOutputStream())
        {
            readResource(resource, baos);
            
            return baos.toString();
        }
    }
    
    public static void copyFile(File sourceFile, File destFile)
            throws IOException
    {
        if (!destFile.exists())
        {
            destFile.getParentFile().mkdirs();
            destFile.createNewFile();
        }
        
        try (
            FileInputStream source = new FileInputStream(sourceFile);
            FileOutputStream destination = new FileOutputStream(destFile);
        )
        {
            try (
                FileChannel sourceChannel = source.getChannel();
                FileChannel destinationChannel = destination.getChannel();
            )
            {
                destinationChannel.transferFrom(
                        sourceChannel, 0, sourceChannel.size()
                );
            }
        }
    }
}