如何在java中为泛型类创建泛型构造函数?

I want to create a KeyValue class but in generic manner and this is what I've written:

我想创建一个KeyValue类，但是以通用的方式，这是我写的:

public class KeyValue<T,E> 
{

    private T key;
    private E value;
    /**
     * @return the key
     */
    public T getKey() {
        return key;
    }
    /**
     * @param key the key to set
     */
    public void setKey(T key) {
        this.key = key;
    }
    /**
     * @return the value
     */
    public E getValue() {
        return value;
    }
    /**
     * @param value the value to set
     */
    public void setValue(E value) {
        this.value = value;
    }

    public KeyValue <T, E>(T k , E v) // I get compile error here
    {
        setKey(k);
        setValue(v);
    }
}

the error says : "Syntax error on token ">", Identifier expected after this token"

错误是:“在令牌“>”上的语法错误，该令牌后面预期的标识符”

how should I create a generic constructor in java then?

那么，我应该如何在java中创建泛型构造函数呢?

3 个解决方案

#1

You need to remove <T, E> from the constructor's signature: it's already there implicitly.

您需要从构造函数的签名中删除 :它已经隐式地存在了。 ,>

public KeyValue(T k , E v) // No compile errors here :)
{
    setKey(k);
    setValue(v);
}

#2

Write constructor exactly the same way you wrote other methods

编写构造函数的方式与编写其他方法的方式完全相同

public KeyValue(T k , E v) 
    {
        setKey(k);
        setValue(v);
    }

#3

the constructor can be written as

构造函数可以写成

public<T,E> KeyValue(T k,E v){}

but its not necessary also we can writepublic KeyValue(T k,E v)

但也没有必要我们可以写公钥值(tk,E v)

#1