You haven't specified what kind of elements the list contains, if it is a primitive data type then you can print out the elements. But if the elements are objects then as Kshitij Mehta mentioned you need to implement (override) the method "toString" within that object - if it is not already implemented - and let it return something meaning full from within the object, example: class Person { private String firstName; private String lastName; @Override public String toString() { return this.firstName + " " + this.lastName; } }

    list.stream().map(x -> x.getName()).forEach(System.out::println);

或者你可以简单地使用Apache Commons实用程序:

https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/ArrayUtils.html#toString-java.lang.Object-

List<MyObject> myObjects = ...
System.out.println(ArrayUtils.toString(myObjects));

System.out.println(列表);对我有用。

下面是一个完整的例子:

import java.util.List;    
import java.util.ArrayList;

public class HelloWorld {
     public static void main(String[] args) {
        final List<String> list = new ArrayList<>();
        list.add("Hello");
        list.add("World");
        System.out.println(list);
     }
}

它将打印[Hello, World]。

System.out.println(list);//toString() is easy and good enough for debugging.

AbstractCollection的toString()将非常干净和容易做到这一点。AbstractList是AbstractCollection的子类，因此不需要for循环，也不需要toArray()。

返回此集合的字符串表示形式。字符串表示形式由集合元素的列表组成 它们由迭代器返回的顺序，用方括号括起来 (“[]”)。相邻元素用字符“，”(逗号)分隔 和空间)。通过将元素转换为字符串 String.valueOf(对象)。

如果您正在使用列表中的任何自定义对象，例如Student，则需要重写它的toString()方法(重写这个方法总是好的)以获得有意义的输出

请看下面的例子:

public class TestPrintElements {

    public static void main(String[] args) {

        //Element is String, Integer,or other primitive type
        List<String> sList = new ArrayList<String>();
        sList.add("string1");
        sList.add("string2");
        System.out.println(sList);

        //Element is custom type
        Student st1=new Student(15,"Tom");
        Student st2=new Student(16,"Kate");
        List<Student> stList=new ArrayList<Student>();
        stList.add(st1);
        stList.add(st2);
        System.out.println(stList);
   }
}


public  class Student{
    private int age;
    private String name;

    public Student(int age, String name){
        this.age=age;
        this.name=name;
    }

    @Override
    public String toString(){
        return "student "+name+", age:" +age;
    }
}

输出:

[string1, string2]
[student Tom age:15, student Kate age:16]

这取决于List中存储的对象类型，以及它是否有toString()方法的实现。System.out.println(list)应该打印所有标准java对象类型(String, Long, Integer等)。在这种情况下，如果我们使用自定义对象类型，那么我们需要重写自定义对象的toString()方法。

例子:

class Employee {
 private String name;
 private long id;

 @Override
 public String toString() {
   return "name: " + this.name() + 
           ", id: " + this.id();
 }  
}

测试:

class TestPrintList {
   public static void main(String[] args) {
     Employee employee1 =new Employee("test1", 123);
     Employee employee2 =new Employee("test2", 453);
     List<Employee> employees = new ArrayList(2);
     employee.add(employee1);
     employee.add(employee2);
     System.out.println(employees);
   }
}