Extract the difference between two strings in Java
Hi I have two strings :
String hear = "Hi My name is Deepak"
+ "\n"
+ "How are you ?"
+ "\n"
+ "\n"
+ "How is everyone";
String dear = "Hi My name is Deepak"
+ "\n"
+ "How are you ?"
+ "\n"
+ "Hey there \n"
+ "How is everyone";
I want to get what is not present in the hear string that is "Hey There \n". I found a method , but it fails for this case :
static String strDiffChop(String s1, String s2) {
if (s1.length() > s2.length()) {
return s1.substring(s2.length() - 1);
} else if (s2.length() > s1.length()) {
return s2.substring(s1.length() - 1);
} else {
return "";
}
}
Can any one help ?
google-diff-match-patch
The Diff Match and Patch libraries offer robust algorithms to perform the operations required for synchronizing plain text.
Diff:
Compare two blocks of plain text and efficiently return a list of differences.
Match:
Given a search string, find its best fuzzy match in a block of plain text. Weighted for both accuracy and location.
Patch:
Apply a list of patches onto plain text. Use best-effort to apply patch even when the underlying text doesn't match.
Currently available in Java, JavaScript, Dart, C++, C#, Objective C, Lua and Python. Regardless of language, each library features the same API and the same functionality. All versions also have comprehensive test harnesses.
There is a Line or word diffs wiki page which describes how to do line-by-line diffs.
One can use the StringUtils
from Apache Commons. Here is the StringUtils API.
public static String difference(String str1, String str2) {
if (str1 == null) {
return str2;
}
if (str2 == null) {
return str1;
}
int at = indexOfDifference(str1, str2);
if (at == -1) {
return EMPTY;
}
return str2.substring(at);
}
public static int indexOfDifference(String str1, String str2) {
if (str1 == str2) {
return -1;
}
if (str1 == null || str2 == null) {
return 0;
}
int i;
for (i = 0; i < str1.length() && i < str2.length(); ++i) {
if (str1.charAt(i) != str2.charAt(i)) {
break;
}
}
if (i < str2.length() || i < str1.length()) {
return i;
}
return -1;
}
I have used the StringTokenizer to find the solution. Below is the code snippet
public static List<String> findNotMatching(String sourceStr, String anotherStr){
StringTokenizer at = new StringTokenizer(sourceStr, " ");
StringTokenizer bt = null;
int i = 0, token_count = 0;
String token = null;
boolean flag = false;
List<String> missingWords = new ArrayList<String>();
while (at.hasMoreTokens()) {
token = at.nextToken();
bt = new StringTokenizer(anotherStr, " ");
token_count = bt.countTokens();
while (i < token_count) {
String s = bt.nextToken();
if (token.equals(s)) {
flag = true;
break;
} else {
flag = false;
}
i++;
}
i = 0;
if (flag == false)
missingWords.add(token);
}
return missingWords;
}
convert the string to lists and then use the following method to get result How to remove common values from two array list