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我想比较两个基于md5散列和数组匹配的文件，以使性能高效处理.i.e。如果两个字节值匹配，那么两个文件的内容都是相同的，否则它将移动到数组匹配以找出两个文件之间的差异。问题是我在这里面临的是对于相同的文件字节值是不同的，所以它正在移动到数组匹配，在这种情况下它不是必需的。Java - 两个文件与散列和数组匹配比较
Java代码：
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.concurrent.TimeUnit;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class CompareTwoFiles {
static int count1 = 0 ;
static int count2 = 0 ;
static String arrayLines1[] = new String[countLines("\\Files_Comparison\\File11.txt")];
static String arrayLines2[] = new String[countLines("\\Files_Comparison\\File12.txt")];
public static void main(String args[]) throws Throwable{
long lStartTime = new Date().getTime();
System.out.println("File1 count=" + countLines("\\Files_Comparison\\File11.txt"));
System.out.println("File2 count=" + countLines("\\Files_Comparison\\File12.txt"));
MessageDigest md_1 = MessageDigest.getInstance("MD5");
MessageDigest md_2 = MessageDigest.getInstance("MD5");
InputStream is_1 = new FileInputStream("\\Files_Comparison\\File11.txt");
InputStream is_2 = new FileInputStream("\\Files_Comparison\\File12.txt");
try {
is_1 = new DigestInputStream(is_1, md_1);
is_2 = new DigestInputStream(is_2, md_2);
}
finally {
is_1.close();
is_2.close();
}
byte[] digest_1 = md_1.digest();
byte[] digest_2 = md_2.digest();
System.out.println(digest_1);
System.out.println(digest_2);
if (digest_1.equals(digest_2)) {
System.out.println("File Comparison Process Completed");
System.out.println("Both files are same");
}
else
{
findDifference("\\Files_Comparison\\File11.txt","\\Files_Comparison\\File12.txt");
displayRecords();
System.out.println("File Comparison Process Completed");
}
long lEndTime = new Date().getTime();
long difference = lEndTime - lStartTime;
String hms = String.format("%02d:%02d:%02d", TimeUnit.MILLISECONDS.toHours(difference),
TimeUnit.MILLISECONDS.toMinutes(difference) - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(difference)),
TimeUnit.MILLISECONDS.toSeconds(difference) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(difference)));
System.out.println(hms);
}
public static int countLines(String File){
int lineCount = 0;
try {
BufferedReader br = new BufferedReader(new FileReader(File));
while ((br.readLine()) != null) {
lineCount++;
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return lineCount;
}
public static void findDifference(String File1, String File2){
String contents1 = null;
String contents2 = null;
try
{
FileReader file1 = new FileReader(File1);
FileReader file2 = new FileReader(File2);
BufferedReader buf1 = new BufferedReader(file1);
BufferedReader buf2 = new BufferedReader(file2);
while ((contents1 = buf1.readLine()) != null)
{
arrayLines1[count1] = contents1 ;
count1++;
}
while ((contents2 = buf2.readLine()) != null)
{
arrayLines2[count2] = contents2 ;
count2++;
}
}catch (Exception e){
e.printStackTrace();
}
}
public static void displayRecords() {
for (int i = 0 ; i < arrayLines1.length && i < arrayLines2.length; i++)
{
String a = arrayLines1[i];
String b = arrayLines2[i];
if(!a.contains(b)) {
System.out.println(a);
}
}
}
}