CopyCharStream.java

/*
 * GovWay - A customizable API Gateway 
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 * 
 * Copyright (c) 2005-2025 Link.it srl (https://link.it). 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3, as published by
 * the Free Software Foundation.
 *
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package org.openspcoop2.utils;

import java.io.File;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.nio.file.CopyOption;
import java.nio.file.Files;

import org.apache.commons.io.IOUtils;
import org.apache.commons.io.input.ReaderInputStream;
import org.apache.commons.io.output.WriterOutputStream;
import org.apache.commons.lang.CharEncoding;

import com.google.common.io.CharStreams;

/**
 * Libreria contenente metodi per copiare gli stream di stringhe (Reader e Writer)
 *
 *
 * @author Poli Andrea (apoli@link.it)
 * @author $Author$
 * @version $Rev$, $Date$
 */
public class CopyCharStream {


    
    /** Copy Sring */
    
    public static void copy(Reader reader, OutputStream out) throws UtilsException{
        copy(CopyStreamMethod.AUTO, reader, out);
    }
    public static void copy(CopyStreamMethod method, Reader reader, OutputStream out) throws UtilsException{
        try {
            Writer writer = new OutputStreamWriter(out);
            CopyCharStream.copy(method, reader, writer);
            out.flush();
            writer.close();
        }catch(Exception e) {
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static void copy(Reader reader, Writer writer) throws UtilsException{
        copy(CopyStreamMethod.AUTO, reader, writer);
    }
    public static void copy(CopyStreamMethod method, Reader reader,Writer writer) throws UtilsException{
        switch (method) {
        case JAVA:
            copyBuffer(reader,writer);
            break;
        case JAVA_TRANSFER_TO:
            transferTo(reader,writer);
            break;
        case JAVA_NIO:
            copyChannels(reader,writer);
            break;
        case GUAVA:
            copyGuava(reader,writer);
            break;
        case COMMONS_IO:
            copyCommonsIO(reader,writer);
            break;
        case AUTO:
//          if(reader instanceof java.io.FileReader || writer instanceof java.io.FileWriter) {
//              copyChannels(reader,writer);    
//          }
//          else {
//              transferTo(reader,writer);
//          }
            // Nel caso di char e' sempre piu' efficiente il transferTo
            transferTo(reader,writer);
            break;
        }
    }
    
    public static void copyBuffer(Reader reader,Writer writer) throws UtilsException{
        try{
            char [] buffer = new char[Utilities.DIMENSIONE_BUFFER];
            int letti = 0;
            while( (letti=reader.read(buffer)) != -1 ){
                writer.write(buffer, 0, letti);
            }
            writer.flush();
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static void transferTo(Reader reader,Writer writer) throws UtilsException{
        try{
            reader.transferTo(writer);
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static void copyGuava(Reader reader,Writer writer) throws UtilsException{
        try{
            CharStreams.copy(reader, writer);
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static void copyCommonsIO(Reader reader,Writer writer) throws UtilsException{
        try{
            IOUtils.copy(reader, writer);
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static void copyChannels(final Reader reader, final Writer writer) throws UtilsException {
        try {
            try(
                    ReaderInputStream src = ReaderInputStream.builder()
                               .setReader(reader)
                               .setCharset(CharEncoding.UTF_8)
                               .get(); 
                    WriterOutputStream dest = WriterOutputStream.builder()
                                .setWriter(writer)
                                .setCharset(CharEncoding.UTF_8)
                                .get();
                ){
            final ReadableByteChannel inputChannel = Channels.newChannel(src);
            final WritableByteChannel outputChannel = Channels.newChannel(dest);
            copyChannels(inputChannel, outputChannel);
            }
        }catch(Exception e) {
            throw new UtilsException(e.getMessage(),e);
        }
    }
    public static void copyChannels(final ReadableByteChannel src, final WritableByteChannel dest) throws UtilsException {
        try{
            final ByteBuffer buffer = ByteBuffer.allocateDirect(Utilities.DIMENSIONE_BUFFER);
                
            while(src.read(buffer) != -1) {
                buffer.flip();
                dest.write(buffer);
                buffer.compact();
            }
                
            buffer.flip();
            
            while(buffer.hasRemaining()) {
                dest.write(buffer);
            }
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static void copy(File from,Writer writer) throws UtilsException{
        try{
            try(
                    WriterOutputStream dest = WriterOutputStream.builder()
                            .setWriter(writer)
                            .setCharset(CharEncoding.UTF_8)
                            .get(); 
                ){
                Files.copy(from.toPath(), dest);
            }
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    public static void copy(File from,File to) throws UtilsException{
        try{
            Files.copy(from.toPath(), to.toPath());
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    public static void copy(File from,File to, CopyOption ... options) throws UtilsException{
        try{
            Files.copy(from.toPath(), to.toPath(), options);
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    public static void copy(Reader reader, File to) throws UtilsException{
        try{
            try(
                    ReaderInputStream from = ReaderInputStream.builder()
                       .setReader(reader)
                       .setCharset(CharEncoding.UTF_8)
                       .get(); 
                ){
                Files.copy(from, to.toPath());
            }
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    public static void copy(Reader reader, File to, CopyOption ... options) throws UtilsException{
        try{
            try(
                    ReaderInputStream from = ReaderInputStream.builder()
                       .setReader(reader)
                       .setCharset(CharEncoding.UTF_8)
                       .get(); 
                ){
                Files.copy(from, to.toPath(), options);
            }
        }catch(Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }

}