java file compare utility

As there is requriement about compare code in two branches , so just write a demo.

function contains:

1.get checksum of string

2.get checksum of files

3.compare two folders.

package com.jsajax.utilities;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.commons.lang.StringUtils;

public class ChecksumUtility {
	public static final String ALGORITHM_MD5="MD5";
	public static final String ALGORITHM_SHA1="SHA-1";
	
	public static final String FOLDER_MAIN="SRC";
	public static final String FOLDER_COMP="DEST";
	
	/***
	 * 
	 * @param input        the string
	 * @param algorithm    the algorithm,e.g MD5 or SHA-1
	 * @return             the string for the resulting hash value
	 */
	public static String stringChecksum(String input , String algorithm) {
		try {
			// 拿到一个MD5转换器（如果想要SHA1参数换成”SHA1”）
			MessageDigest messageDigest = MessageDigest.getInstance(algorithm);
			// 输入的字符串转换成字节数组
			byte[] inputByteArray = input.getBytes();
			// inputByteArray是输入字符串转换得到的字节数组
			messageDigest.update(inputByteArray);
			// 转换并返回结果，也是字节数组，包含16个元素
			byte[] resultByteArray = messageDigest.digest();
			// 字符数组转换成字符串返回
			return byteArrayToHex(resultByteArray);
		} catch (NoSuchAlgorithmException e) {
			return null;
		}
	}
	
	/***
	 * 
	 * @param inputFile         the file path
	 * @param algorithm         the algorithm   e.g MD5 or SHA-1
	 * @return                  the string for the resulting hash value
	 * @throws IOException
	 */
	public static String fileChecksum(String inputFile , String algorithm) throws IOException {
		// 缓冲区大小
		int bufferSize = 256 * 1024;
		FileInputStream fileInputStream = null;
		DigestInputStream digestInputStream = null;
		try {
			// 拿到一个MD5转换器（同样，这里可以换成SHA1）
			MessageDigest messageDigest = MessageDigest.getInstance(algorithm);
			// 使用DigestInputStream
			fileInputStream = new FileInputStream(inputFile);
			digestInputStream = new DigestInputStream(fileInputStream,
					messageDigest);
			// read的过程中进行MD5处理，直到读完文件
			byte[] buffer = new byte[bufferSize];
			while (digestInputStream.read(buffer) > 0)
				;
			// 获取最终的MessageDigest
			messageDigest = digestInputStream.getMessageDigest();
			// 拿到结果，也是字节数组，包含16个元素
			byte[] resultByteArray = messageDigest.digest();
			// 同样，把字节数组转换成字符串
			return byteArrayToHex(resultByteArray);
		} catch (NoSuchAlgorithmException e) {
			return null;
		} finally {
			try {
				digestInputStream.close();
			} catch (Exception e) {
			}
			try {
				fileInputStream.close();
			} catch (Exception e) {
			}
		}
	}
	
	/***
	 * 
	 * @param byteArray       array of byte
	 * @return                string converted from the byteArray e.g bype[0]=60-->0011 1100-->"3C"
	 */
	// 下面这个函数用于将字节数组换成成16进制的字符串
	public static String byteArrayToHex(byte[] byteArray) {
		// 首先初始化一个字符数组，用来存放每个16进制字符
		char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9','A', 'B', 'C', 'D', 'E', 'F' };
		// new一个字符数组，这个就是用来组成结果字符串的（解释一下：一个byte是八位二进制，
		// 也就是2位十六进制字符（2的8次方等于16的2次方））
		char[] resultCharArray = new char[byteArray.length * 2];
		// 遍历字节数组，通过位运算（位运算效率高），转换成字符放到字符数组中去
		int index = 0;
		for (byte b : byteArray) {
			resultCharArray[index++] = hexDigits[b >>> 4 & 0xf];
			resultCharArray[index++] = hexDigits[b & 0xf];
		}
		// 字符数组组合成字符串返回
		return new String(resultCharArray);
	}
	
	/***
	 * 
	 * @param srcFolder        			E:\document\java\test\main\XXX
	 * @param destFolder     			E:\document\java\test\comp\XXX
	 * @remark                    		when compare the 2 folders , the structure under XXX should be same.
	 * @param firstSameFolderName		XXX
	 * @param outputFolder				the output folder about the compare result.
	 * @return                  		the checksum of both folders.
	 */
	public static void folderCompare(String srcFolder,String destFolder,String firstSameFolderName,String outputFolder){
		File srcF = new File(srcFolder);
		File destF = new File(destFolder);
		
		Map<String,String> srcChecksumMap= new HashMap<String,String>();
		Map<String,String> destChecksumMap= new HashMap<String,String>();
		List<String> allFileList = new ArrayList<String>();
		List<String> deleteList = new ArrayList<String>();
		List<String> copyList = new ArrayList<String>();
		
		if(srcF.exists()&&srcF.canRead() && destF.exists() && destF.canRead()){
			getFileChecksum(srcF,srcChecksumMap,firstSameFolderName);
			getFileChecksum(destF,destChecksumMap,firstSameFolderName);
			
			gatherAllFiles(srcChecksumMap,destChecksumMap,allFileList);
			
			System.out.println("srcFolder = "+srcFolder);
			System.out.println("destFolder = "+destFolder);
			if(allFileList.size()>0){
				int index = 1;
				String srcFileSum;
				String descFileSum;
				for(String str : allFileList){
					srcFileSum = srcChecksumMap.get(str);
					descFileSum = destChecksumMap.get(str);
					
					if(StringUtils.isBlank(srcFileSum) && StringUtils.isNotBlank(descFileSum)){
						System.out.println("File["+index+"] = "+str+"\t\tTO_DELETE");
						deleteList.add(destFolder+"\\"+str);
					}else if(StringUtils.isNotBlank(srcFileSum) && StringUtils.isBlank(descFileSum)){
						System.out.println("File["+index+"] = "+str+"\t\tTO_COPY");
						copyList.add(str);
					}else if(StringUtils.isNotBlank(srcFileSum) && StringUtils.isNotBlank(descFileSum) && !srcFileSum.equalsIgnoreCase(descFileSum)){
						System.out.println("File["+index+"] = "+str+"\t\tTO_MODIFY");
						copyList.add(str);
					}else{
						System.out.println("File["+index+"] = "+str);
					}
					System.out.println("Checksum in srcFolder = "+srcFileSum +"\t\t in destFolder = "+descFileSum);
					index++;
				}
			}
		}else{
			System.out.println("Both folder can not be read.");
		}
		System.out.println("Delete below files:");
		deleteBelowFiles(deleteList);
		
		System.out.println("Copy out below files:");
		copyBelowFIles(copyList,srcFolder,outputFolder);
		
	}
	
	public static void copyBelowFIles(List<String> copyList,String from , String to){
		if(copyList.size()>0){
			File f;
			try {
				for(String s:copyList){
					f = new File(to+File.separator+s);
					CopyUtility.copyFile(from+File.separator+s, to+File.separator+s);
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}
	
	public static void deleteBelowFiles(List<String> deleteList){
		if(deleteList.size()>0){
			for(String s:deleteList){
				System.out.println(s);
                                //TODO...
			}
		}
	}
	
	public static void gatherAllFiles(Map<String,String> srcChecksumMap,Map<String,String> destChecksumMap , List<String> allFileList){
		Set<String> srcFileList = srcChecksumMap.keySet();
		Set<String> destFileList = destChecksumMap.keySet();

		if(srcFileList.size()>0){
			for(String s:srcFileList){
				if(!allFileList.contains(s)){
					allFileList.add(s);
				}
			}
		}
		if(destFileList.size()>0){
			for(String s:destFileList){
				if(!allFileList.contains(s)){
					allFileList.add(s);
				}
			}
		}
	}
	
	/***
	 * 
	 * @param file							the File entity of file path "E:\document\java\test\main\XXX"
	 * @param checksumMap					the result checksum map
	 * @param firstSameFolderName			it is XXX
	 */
	public static void getFileChecksum(File file,Map<String,String> checksumMap,String firstSameFolderName){
		if(file.isFile()){
			String relativePath = file.getAbsolutePath().substring(file.getAbsolutePath().indexOf(firstSameFolderName)+firstSameFolderName.length()+1);
			try {
				checksumMap.put(relativePath, fileChecksum(file.getAbsolutePath() , ChecksumUtility.ALGORITHM_SHA1));
			} catch (IOException e) {
				checksumMap.put(relativePath,"encounter exception.");
			}
			return;
		}else{
			File[] files = file.listFiles();
			if(files !=null && files.length >0){
				for(File f : files){
					if(!f.getName().startsWith(".")){ // if the directory or file name is started with '.' , ignore it
						getFileChecksum(f,checksumMap,firstSameFolderName);
					}
				}
			}else{
				return;
			}
		}
	}
	
	public static void main(String[] args) {
		ChecksumUtility.folderCompare("E:\\document\\java\\111111testfolder\\main\\123", 
				"E:\\document\\java\\111111testfolder\\comp\\123", "123", "E:\\document\\java\\111111testfolder\\result");
	}
}

 

package com.jsajax.utilities;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class CopyUtility {
	public static void createDir(String fileToPath){
		String folder = fileToPath.substring(0,fileToPath.lastIndexOf(File.separator));
		File f = new File(folder);
		if(!f.exists()){
			System.out.println("Create folder "+folder);
			f.mkdirs();
		}
	}
	public static void createFile(String fileToPath) throws IOException{
		File f = new File(fileToPath);
		if(!f.exists()){
			System.out.println("Create file "+fileToPath);
			f.createNewFile();
		}
	}
	
	public static void copyFile(String fileFromPath, String fileToPath){
		InputStream in = null;
		OutputStream out = null;
		try {
			createDir(fileToPath);
			createFile(fileToPath);
			in = new FileInputStream(fileFromPath);
			out = new FileOutputStream(fileToPath);
			int length = in.available();
			int len = (length % 1024 == 0) ? (length / 1024): (length / 1024 + 1);
			byte[] temp = new byte[1024];
			for (int i = 0; i < len; i++) {
				in.read(temp);
				out.write(temp);
			}
		} catch(Exception e){
			e.printStackTrace();
		} finally {
			if (in != null)
				try {
					in.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			if (out != null)
				try {
					out.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
		}
	}
}