JavaUtils/src/net/droidtech/io/DroidFile.java

package net.droidtech.io;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.security.MessageDigest;

public class DroidFile extends File{

	private static final long serialVersionUID = 7311643678032690177L;
	private File file=null;
	
	public DroidFile(String path){
		super(path);
		file=new File(path);
	}
	public DataInputStream getInputStream(){
		try {
			if(file.exists()&&!file.isDirectory()){
			    DataInputStream in=new DataInputStream(new FileInputStream(file));
			    return in;
			}else{
				return null;
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			return null;
		}
		
	}
	
	public DataOutputStream getOutputStream(){
		try {
			if(file.exists()&&!file.isDirectory()){
			    DataOutputStream out=new DataOutputStream(new FileOutputStream(file));
			    return out;
			}else{
				return null;
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			return null;
		}
	}
	
	public void copyTo(File target){
		DroidFile file=new DroidFile(target.getAbsolutePath());
		if(file.createNewFile()){
		    StreamWriter writer=new StreamWriter();
		    writer.writeStream(this.getInputStream(),file);
		}
	}
	
	@Override
	public boolean createNewFile(){
		try {
			File parentDir=new File(file.getParent());
			if(!parentDir.exists()){
				parentDir.mkdirs();
			}
			file.createNewFile();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			return false;
		}
		return file.exists();
	}
	
	@Override
	public boolean mkdir(){
		file.mkdirs();
		return file.exists();
	}
	
	public String getMD5String(){
		byte[] md5data=getMD5Bytes();
		if(md5data!=null){
			return new BigInteger(1,md5data).toString(16);
		}else{
			return null;
		}
	}
	
	public byte[] getMD5Bytes(){
		DataInputStream in=this.getInputStream();
		if(in==null){
			return null;
		}
		try {
			byte[] buffer=new byte[4096];
			MessageDigest md5=MessageDigest.getInstance("MD5");
			while(true){
				int count=in.read(buffer);
				if(count!=-1){
				md5.update(buffer,0,count);
				}else{
					in.close();
					break;
			}
		}
			return md5.digest();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
	}
	
	public DroidFile getChildFile(String name){
		if(!this.isDirectory()){
			return null;
		}
		return new DroidFile(this.getAbsolutePath()+File.separator+name);
	}
}