将类对象转换为人类可读字符串

Question

Is there any way in which I can automatically convert a Custom Class Object into a human readable string?

eg consider the following class:

class Person {
    String Name;
    int Salary;
    ...
}

Person p = new Person();
p.setName("Tony");
p.setSalary(1000);

I need to get something like:

Person: Name="Tony", Salary=1000

Answer 1

Importing Commons Lang you could use ToStringBuilder

Check method reflectionToString(java.lang.Object) , this will create automatically the representation you are expecting.

This code:

Person p = new Person();
p.setName("Tony");
p.setSalary(1000);

System.out.println(ToStringBuilder.reflectionToString(p));

results this string:

Person@64578ceb[Name=Tony,Salary=1000]

Answer 2

This is basically what toString is for. But given you want this done automatically, you can create some general service that can do it. Use reflection to iterate all fields, and then print each one's name and value. Simplest way to print their values would be by using their toString , but you can also pass them into that printing service recursively on some cases (you'll have to find the halt condition, of course).

For example, on some class PrintUtils have:

public static void printFields(Object o) {
    System.out.print(o.getClass.getSimpleName() + ": ");
    for (Field field : o.getClass().getDeclaredFields()) {
        field.setAccessible(true);     // you also get non-public fields
        System.out.print(field.getName() + " = " + field.get(o) + ", ");
    }
}

You'll have to handle exceptions etc. and possibly better format the output, of course. Also, this only print fields declared in the current class. If you want fields declared higher in the inheritance hierarchy, you'll have to work a bit more. Lastly, using reflection is much slower than just having a regular toString . If using toString is possible, it is preferable.

Answer 3

sure you can override the toString method of class.

as follow:

class Person {
    String name;
    int salary;
    ...
    @Override public String toString() {
      return "Person: Name='" + name + "', Salary=" + salary;
    }
}

refer for more details https://blogs.oracle.com/CoreJavaTechTips/entry/writing_tostring_methods_tech_days

Answer 4

我认为你可以使用ToStringBuilder ，它是commons-lang一部分。

Answer 5

class Person {
    String Name;
    int Salary;
    ...

   @Override
   public String toString() {
     return "Person: Name = " + Name + "," +
             "Salary="+Salary;
   }
}

Person p = new Person();
p.setName("Tony");
p.setSalary(1000);
System.out.println(p.toString());

Answer 6

One way to do it is to rely on Apache Commons BeanUtils.describe . This will produce a Map of bean's properties, which converts to a string nicely via Map.toString . If you want something more custom, you'll need to dig into the reflection API.

Answer 7

你可以使用java中的消息格式： https ：//docs.oracle.com/javase/tutorial/i18n//message.html seperate variable by - 你的类中有一个可读的字符串！