java - 构造函数 ClassCountry(String, String, String, int) 未定义

Question

Eclipse 一直说构造函数未定义 - 这里出了什么问题？我已经检查了一切。

package exerciseOne;

public class TestCountryClass {

    public static void main(String[] args) {

        ClassCountry oCon1 = new ClassCountry("Iceland", "Icelandic", "króna", 400000);         

        System.out.printf("%s %s %d%n", oCon1.getCountryName(),
                                        oCon1.getCountryLanguage(),
                                        oCon1.getCountryCurrency(),
                                        oCon1.getCountryPopulation());

    }

}

这是该类的代码，我已经检查了多次，但 Eclipse 一直返回相同的错误消息。我希望你们能够在这里找到问题；感谢任何帮助:

package exerciseOne;

public class ClassCountry {

    private String countryName;
    private String countryLanguage;
    private String countryCurrency;
    private int countryPopulation;

    public void classCountry(String countryName, String countryLanguage, String countryCurrency, int countryPopulation)
    {
        this.countryName = countryName;
        this.countryLanguage = countryLanguage;
        this.countryCurrency = countryCurrency;
        this.countryPopulation = countryPopulation;

    }

    public void setCountryName(String countryName)
    {
        this.countryName = countryName;
    }
    public String getCountryName()
    {
        return countryName;
    }
    public void setCountryLanguage(String countryLanguage)
    {
        this.countryLanguage = countryLanguage;
    }
    public String getCountryLanguage()
    {
        return countryLanguage;
    }
    public void setCountryPopulation(int countryPopulation)
    {
        this.countryPopulation = countryPopulation;
    }
    public int getCountryPopulation()
    {
        return countryPopulation;
    }

    public void setCountryCurrency(String countryCurrency)
    {
        this.countryCurrency = countryCurrency;
    }
    public String getCountryCurrency()
    {
        return countryCurrency;
    }

}

Answer 1

public void classCountry(String countryName, String countryLanguage, String countryCurrency, int countryPopulation)
{
    this.countryName = countryName;
    this.countryLanguage = countryLanguage;
    this.countryCurrency = countryCurrency;
    this.countryPopulation = countryPopulation;

}

这是你的问题。您已将其添加为构造函数，但这不是构造函数。这是一个返回类型为 void 的方法。

将上面的内容更改为:

public ClassCountry(String countryName, String countryLanguage, String countryCurrency, int countryPopulation)
{
    this.countryName = countryName;
    this.countryLanguage = countryLanguage;
    this.countryCurrency = countryCurrency;
    this.countryPopulation = countryPopulation;

}

有关构造函数的更多信息，可以查看这个Oracle tutorial .