How to replace \" with empty value

I have a JSON string:

{
    "key1": "abc",
    "key2": "def",
    "key3": "gh\"i\"j"
}

Expected o/p:

{
    "key1": "abc",
    "key2": "def",
    "key3": "ghij"
}

Java string replace() and replaceAll() are replacing all double quotes:

System.out.println(a.replaceAll("\\\"",""));

System.out.println(a.replace("\"",""));

Output:

{
    key1: abc,
    key2: def,
    key3: ghij
}

The reason I'm trying to replace \" is that some operation has to be done using JSON, escaping special characters and storing the JSON string to a database. Here the json becomes invalid because of \".

How can I replace only \" with empty value?