CODEWITHSUNDEEP
javahashmaptostring
Archana
Archana

Reputation: 659

Howto convert the value of a hashmap to String i Java

I have a HashMap. I am trying to retrieve the value and print it using the key from the user-code.

The code is:

lib.addbook(book2.getISBN(), book2);
Book ret = lib.getbook("978-81-291-1979-7");
System.out.println(ret);

Current Output:

O/P: LibraryPackage.Book@527c6768

I want the output to be a string and to display the actual value not the address of the book.

Upvotes: 1

Views: 547

Answers (2)

2v0mjdrl
2v0mjdrl

Reputation: 575

You have to implement (and override) the toString() method in your Book class, and specify what you want the output to be. E.g.:

@Override
String toString()
{
  return this.author+": " + this.title;
}

Upvotes: 5

Matt
Matt

Reputation: 11805

commons-lang has a great utility for this if you don't want to override the .toString() method, or need to represent it differently in different situations:

Here's a call to build a string based on reflection:

String str = ToStringBuilder.reflectionToString(object);

In fact, this is a great way to implement the .toString() method itself. Another alternative use of this class would be a field by field creation of the string:

String str = new ToStringBuilder(object)
    .append("field1", field1)
    .append("field2", field2)
    .toString();

Upvotes: 0

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