CODEWITHSUNDEEP
javaxmldiff
m Goodman
m Goodman

Reputation: 31

How to diff-compare two xml files using java

I have two xml files that I want to compare:

old.xml:

<EMPLOYEES>
  <employee>
    <id>102</id>
    <name>Fran</name>
    <department>  THIS IS COMPUTER DEPARTMENT  </department>
  </employee> 
  <employee>
    <id>105</id>
    <name>Matthew</name>
    <department> THIS IS SCIENCE AND TECHNOLOGY </department>
  </employee> 
</EMPLOYEES>

new.xml :

<EMPLOYEES>
  <employee>
    <id>105</id>
    <name>Matthew</name>
    <department>  THIS IS SCIENCE AND TECHNOLOGY **Modified *** </department>
  </employee> 
  <employee>
    <id>106</id>
    <name>xyz</name>
    <department> THIS IS SCIENCE AND TECHNOLOGY </department>
  </employee>
  <employee>
    <id>107</id>
    <name>Francis</name>
    <department>  THIS IS XYZ  </department>
  </employee>
</EMPLOYEES>

I want to compare the two files and return which records were added, deleted, or updated. old.xml contains 2 <employee> records and new.xml contains 3 <employee> records.

I'd like the results to be like this:

Added records 2 : ex:- employee.id=106 and employee.id=107

Deleted records 1 : ex:- employee.id=102

Updated records 1: ex:- employee.id=105 updated with ----

What is the best way to diff these two XML files to get these results?

Upvotes: 3

Views: 25677

Answers (3)

Prashant Kalyan
Prashant Kalyan

Reputation: 1

For logical difference, i.e. difference between corresponding nodes in two xml files, you may use the isEqualNode(Node node) method of the node class.

For line by line comparison, Scanner is easy to use. Sample code - 

    public void compareFiles (Scanner file1, Scanner file2) {
                String lineA ;
                String lineB ;

                int x = 1;

                    while (file1.hasNextLine() && file2.hasNextLine()) {
                        lineA = file1.nextLine();
                        lineB = file2.nextLine();

                        if (!lineA.equals(lineB)) {
                            System.out.print("Diff " + x++ + "\r\n");
                            System.out.print("< " + lineA + "\r\n");
                            System.out.print("> " + lineB + "\r\n");
                        }
                    }

            }

Upvotes: 0

Evgeniy Dorofeev
Evgeniy Dorofeev

Reputation: 136022

What I would do

@XmlRootElement
class Employees {
    List<Employee> list;
}

class Employee {
    int id;
    String name;
    String department;
}

Unmarshal xmls. Create 2 maps and do following

    Map<Integer, Employee> map1 = ...
    Map<Integer, Employee> map2 = ...
                // see Map.retainAll API
    map1.keySet().retainAll(map2.keySet());
    // now map1 contains common employees
    for (Integer k : map1.keySet()) {
        Employee e1 = map1.get(k);
        Employee e2 = map2.get(k);
        // compare name and department
    }

Upvotes: 1

Marc Baumbach
Marc Baumbach

Reputation: 10473

This sounds similar to Best way to compare 2 XML documents in Java. I'd suggest checking out XMLUnit:

http://xmlunit.sourceforge.net/

Upvotes: 2

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