如何一個JSONObject轉換爲對象包含java.util.Set中的場

Question

有一個模型類：

public class Book { 
    private String id; 
    private Set<String> authors = new HashSet<String>(); //Set field 

    public String getId() { 
     return id; 
    } 
    public void setId(String id) { 
     this.id = id; 
    } 
    public Set<String> getAuthors() { 
     return authors; 
    } 
    public void setAuthors(Set<String> authors) { 
     this.authors = authors; 
    } 
    @Override 
    public String toString() { 
     return "Book [authors=" + authors + ", id=" + id + "]"; 
    } 
} 

我執行以下功能：

public void test3() { 
    Book book = new Book(); 
    book.setId("T2"); 
    Set<String> authors = new HashSet<String>(); 
    authors.add("Tom"); 
    authors.add("King"); 
    book.setAuthors(authors); 

    JSONObject jsonObject = JSONObject.fromObject(book); 
    System.out.println(jsonObject); 

    Book b = (Book) JSONObject.toBean(jsonObject, Book.class); 
    System.out.println(b.toString()); 

} 

它不能轉換的JSONObject到書對象，並會有一個例外。 如何將jsonObject轉換爲Book對象成功？

Answer 1

嘗試Gson：

Book b = new Gson().fromJson(jsonObject, Book.class);