Java 如何防止setter方法中的参数被更改？

例如，我有以下代码：

public class Weather {
    private int temperature;

    //Set temperature to t.
    //If t goes below -15, temperature should become -15.
    //If t goes above 40, temperature should become 40.
    //If t is already between -15 and 40, it should not be changed.
    public void setTemperature(int t){
        if(t>= -15 && t<= 40){
            temperature = t;
        }
        else if(t< -15){
            temperature = -15;
        }
        else if(t> 40){
            temperature = 40;
        }
    }
}

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然后温度实际上会被设置为10而不是-15，因为setTemperature函数会被调用两次。如果温度已经设置为-15到40之间的值，我需要我的代码忽略setter函数的任何未来调用。我该怎么做？以上代码是我目前所掌握的全部

尝试将Integer改为可为null的状态：

private Integer temperature = null;

public void setTemperature(int t){
    if( temperature != null ) return;

    if(t>= -15 && t<= 40){
      temperature = t;
     }
     else if(t< -15){
      temperature = -15;
     }
     else if(t> 40){
      temperature = 40;
     }
    }
   }

使用Integer.MAX_值初始化温度，如果其值小于该值，则不要在SettTemperature内执行任何操作：

public class TestMan {
    public class Weather {
    private int temperature = Integer.MAX_VALUE;

    //Set temperature to t.
    //If t goes below -15, temperature should become -15.
    //If t goes above 40, temperature should become 40.
    //If t is already between -15 and 40, it should not be changed.
    public void setTemperature(int t){
        if (temperature < Integer.MAX_VALUE) return;
        if(t>= -15 && t<= 40){
            temperature = t;
        }
        else if(t< -15){
            temperature = -15;
        }
        else if(t> 40){
            temperature = 40;
        }
    }
}

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根据您的要求：

如果温度已经设置为-15到40之间的值，我需要我的代码忽略setter函数的任何未来调用

您可以使用一个标志来确定您的setter之前是否已被调用，如果是，则检查之前的温度是否在您的范围内，或者与下面的代码不同：

public class Weather {
private int temperature;
private boolean sette_called = false;
//Set temperature to t.
//If t goes below -15, temperature should become -15.
//If t goes above 40, temperature should become 40.
//If t is already between -15 and 40, it should not be changed.
public void setTemperature(int t){
    if (sette_called)
    {
        if (temperature >= -15 && temperature <= 40)
             return;
    }
    if(t>= -15 && t<= 40){
        temperature = t;
    }
    else if(t< -15){
        temperature = -15;
    }
    else if(t> 40){
        temperature = 40;
    }
    sette_called = true;
}
}

使用整数数据类型。设置温度=零

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如果关键字为true，则尝试标记该关键字。。我永远不会设定未来的温度 {

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为什么会这样？为什么只允许一次更改？第一个值必须在构造函数中给出，并且没有定义更好的setter。您的问题令人困惑。您想做什么？如果值超出-15到40的范围，则允许温度更改，如果值在-15到40之间，则不允许任何更改？如果值>=-15，则我希望t要由客户端设置一次的温度，例如temp1.setTemperature-20，这样，如果客户端尝试再次设置相同的温度，例如temp1.setTemperature10，则温度应保持在-15，而不是更改为10。我需要更新温度，以便客户端可以设置多个温度，例如temp1、temp2、temp3等

public class Weather {
private int temperature;
private boolean sette_called = false;
//Set temperature to t.
//If t goes below -15, temperature should become -15.
//If t goes above 40, temperature should become 40.
//If t is already between -15 and 40, it should not be changed.
public void setTemperature(int t){
    if (sette_called)
    {
        if (temperature >= -15 && temperature <= 40)
             return;
    }
    if(t>= -15 && t<= 40){
        temperature = t;
    }
    else if(t< -15){
        temperature = -15;
    }
    else if(t> 40){
        temperature = 40;
    }
    sette_called = true;
}
}

private Integer temperature = null;

public void setTemperature(int t){
    if( temperature != null) {
        return;
    }

    if(t>= -15 && t<= 40){
      temperature = t;
    } else if(t< -15){
      temperature = -15;
    } else if(t> 40){
      temperature = 40;
    }
 }

        private int temperature;
        bool flag = false;

        //Set temperature to t.
        //If t goes below -15, temperature should become -15.
        //If t goes above 40, temperature should become 40.
        //If t is already between -15 and 40, it should not be changed.
        public int setTemperature(int t)
        {
            if (flag == false)
            {
                if (t >= -15 && t <= 40)
                {
                    temperature = t;
                    flag = true;
                }
                else if (t < -15)
                {
                    temperature = -15;
                    flag = true;
                }
                else if (t > 40)
                {
                    temperature = 40;
                    flag = true;
                }
                return temperature;
            }
            else
            {
                return temperature;
            }
        }