禁用注解

17 Mar 2025 | 阅读 2 分钟

通常，我们需要在完成 Jackson 注解的工作后禁用它。因此，我们使用 ObjectMapper 类的 disable() 方法来禁用注解。

我们将 USE_ANNOTATIONS mapper 特性传递给 ObjectMapper 类的 disable() 方法。

让我们举个例子来理解如何使用 disable() 方法来禁用注解。

DisableAnnotationExample.java

//import required classes and package if any
import java.io.IOException;
import java.util.Scanner;

import com.fasterxml.jackson.annotation.JsonIgnoreType;
import com.fasterxml.jackson.databind.MapperFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

//create class DisableAnnotationExample to understand the working of annotation
public class DisableAnnotationExample {
    
    //main() methods start
    @SuppressWarnings("deprecation")
    public static void main(String args[]) {
        
        // create an instance of ObjectMapper class
        ObjectMapper mapper = new ObjectMapper();
        ObjectMapper mapper1 = new ObjectMapper();
        
        // create Scanner class object
        Scanner sc= new Scanner(System.in);		
        
        // using try-catch for serializing Product
        try {
            
            Product product;
            
            String proId, proName, proPrice, proExpiry, proCode;
            
            System.out.println("Enter Product Id:");
            proId = sc.nextLine();
            
            System.out.println("Enter Product Name");
            proName = sc.nextLine();
            
            System.out.println("Enter Product Code");
            proCode = sc.nextLine();
            
            System.out.println("Enter Product Price");
            proPrice = sc.nextLine();
            
            System.out.println("Enter Product Expiry in dd-mm-yyyy format");
            proExpiry = sc.nextLine();
            
            // set values to Student object by using constructor
            product = new Product(proId, proName, proCode, proPrice, proExpiry);   
            
            String str = mapper
                .writerWithDefaultPrettyPrinter()
                .writeValueAsString(product);
            System.out.println(str);
            
            mapper1.disable(MapperFeature.USE_ANNOTATIONS);
            str = mapper1
                .writerWithDefaultPrettyPrinter()
                .writeValueAsString(product);
            System.out.println(str);
        }
        catch (IOException e) { 
            e.printStackTrace();
        }
        
        //close Scanner class object
        sc.close();
        
    }
}
//create class Product
class Product {  
    
    //Creating properties of Product class  
    public String proId;    
    public Name proName;    
    public String price;
    public String expire;
    
    // constructor
    Product(String proId, String name, String code, String price, String expire){
        this.proId = proId;
        proName = new Name(name, code);
        this.price = price;
        this.expire = expire;
    }
    
}
//create class Name
@JsonIgnoreType
class Name {
    public String name;
    Name(String fName, String code){
        name = fName+" ("+code+")";
    }       
}

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