java toString for any object [duplicate]

Answer 1

There are few ways to implement toString method.

1. Reflections (Apache library)

   @Override
   public String toString(){
       return org.apache.commons.lang3.builder.ReflectionToStringBuilder.toString(this);
   }
   

2. JSON based implementation (GSON, Jackson libraries)

   // GSON library for JSON
   @Override
   public String toString(){
       return new com.google.gson.Gson().toJson(this);
   }
   
   // Jackson libabry for JSON/YAML
   @Override
   public String toString() {
       try {
           return new com.fasterxml.jackson.databind.ObjectMapper().writerWithDefaultPrettyPrinter().writeValueAsString(this);
       } catch (com.fasterxml.jackson.core.JsonProcessingException e) {
           e.printStackTrace();
       }
       return null;
   }
   

3. ToStringBuilder (available with apache-commons library)

   @Override
   public String toString() {
       return new org.apache.commons.lang3.builder.ToStringBuilder(this).
           append("field1", field1).
           append("field2", field2).
           toString();
   }
   

4. Hard-core toString() implementation

   @Override
   public String toString() {
       return new StringBuilder()
           .append("field1:"+field1)
           .append("field2:"+field2)
           .toString();
   }