注：これは、same question on the Salesforce SE siteの回答からコピー/貼り付けされています。
いいえ、書面（API v41.0）では、SalesforceにはYAMLを作成または解析するための組み込み機能はありません。つまり、独自のものを構築する必要があります（または、Javaなどの別の言語のものをApexに適用する必要があります）。
一般的なパーサー（有効なYAMLを処理できるもの）を探しておらず、受け取るデータの形式が変更されることを期待していない場合は、ドメイン固有のパーサーを作成する必要がありますあまりにも多くの仕事をしてはいけません。
自分自身がXMLを使って作業しているとき、私は入ってくるスキーマを個々の頂点クラスに分割し、それぞれに構文解析メソッドを構築したいと思います。そうすることで、パーサーは管理しやすくなります。 YAMLで同様のアプローチをとることができます。
// Yes, the need for this BookCollection object is debatable (it's mainly just storing
// a List).
// Encapsulating the parsing makes it worth being made into a class (in my mind).
public class BookCollection{
// The class variables for each level mimic the data stored on each level
// of the schema of your incoming data.
// This will become more apparent later.
public List<Book> item;
public BookCollection(String input){
item = new List<Book>();
// At this level, all we're concerned about is finding the individual books.
// Once we find a book, we pass it down to the next level of parsing (and
// add the result to our list)
// YAML uses whitespace to denote structure, so we need to take that into
// account when splitting.
// The regex here looks for two spaces, a hyphen, one space, a newline.
// Everything after that (up to the next ' - \n' or EOF) is book data.
// String.split() will return 'item:' as the first part.
// That isn't part of the data for a book, so we'll want to remove that.
List<String> bookStringsList = input.split(' - \n');
bookStringsList.remove(0);
for(String bookString :bookStringsList){
Book currentBook = new Book(bookString);
item.add(currentBook);
}
}
}
public class Book{
// Now it should be more apparent that we're mimicking the structure of the
// incoming data.
String title;
String author;
String author_by_last;
String isbn;
String publisher;
Integer on_hand;
Date in_pub_date;
public Book(String input){
// On this level of parsing, we have actual data to work with.
// Our job here is to find all of the key:value pairs, and cast them to
// their appropriate types.
for(String keyAndValue :input.split(' \n')){
String key, value;
List<String> kvSplit = keyAndValue.split(':');
key = kvSplit[0];
// Double quotes are likely to mess things up, so remove them.
value = kvSplit[1].replace('"', '');
// There's probably a more elegant way to handle this than a big 'ol
// if/else if chain...but this'll work
if(key == 'title'){
this.title = value;
} else if(key == 'author'){
this.author = value;
} else if(key == 'author_by_last'){
this.author_by_last = value;
} else if(key == 'isbn'){
this.isbn = value;
} else if(key == 'publisher'){
this.publisher = value;
} else if(key == 'on_hand'){
// String -> Integer is pretty easy, we can use Integer.valueOf()
this.on_hand = Integer.valueOf(value);
} else if(key == 'in_pub_date'){
// Dates are a bit tricky.
// Salesforce wants them in YYYY-MM-DDThh:mm:ssZ format, or the format
// used in your locale (for parse() or valueOf()).
// Given our data, it's easiest to simply generate a new date instance
List<String> dateParts = value.split('-');
this.in_pub_date = Date.newInstance(dateParts[0], dateParts[1], dateParts[2]);
}
}
}
}
これらのクラスの使用は非常に簡単です。ただし、追加の設定が必要です。
// Your YAML, from some source
String myYAML = blackBox.getData();
// Break up your YAML's documents before attempting to parse each one.
List<String> documents = myYAML.split('---\n');
// The first result string will likely always be empty, so we can remove that.
documents.remove(0);
// This is the simple case where we know we're only dealing with a single document.
// If you had multiple documents in a single YAML string, you would (hopefully)
// be able to tell which type of document you were working with (and you'd
// need additional logic to determine which parser class to send the data to).
BookCollection myBooks = new BookCollection(documents[0]);
これらはありません。手動で解析する必要があります。 –