Question

import java.text.DecimalFormat;

public class Cylinder
{

// Instance Variables
private String label = "";
private double radius; 
private double height;
/**
*@param labelIn Represents label value
*@param radiusIn Represents radius value
*@param heightIn Represents height value
*/

public Cylinder(String labelIn, double radiusIn, double heightIn) 

{      
  label = labelIn.trim();
  radius = radiusIn;
  height = heightIn;
}

/**
*@return String representation of label. 
* Accepts no parameters and returns 
* a string representing the label field.
*/
public String getLabel()
{
  return label;
}
/**
* Takes string parameter and returns boolean.
*@param labelIn Command Line used
*@return checks to see if labelIn exist.
*/ 
public boolean setLabel(String labelIn)
{
  if (labelIn == null)
  {
     return false;
  }
  else 
  {
     label = labelIn.trim();
     return true;
  }
}
/**
*@return a method to display a double radius.
* Accepts no parameter and returns double representing 
* radius.
*/ 
public double getRadius()
{
  return radius;
}
/**
*@param radiusIn Command Line used.
* Accepts a double parameter, sets radius field, and
* returns nothing.
*/ 
public void setRadius(double radiusIn)
{ 
  radius = radiusIn;
}
/**
*@return a method to display a double height.
* Accepts no parameters and returns double
* representing the height field.
*/
public double getHeight()
{
  return height;
}
/**
*@param heightIn Command Line used.
* Accepts a double parameter, sets radius field, and 
* returns nothing.
*/ 
public void setHeight(double heightIn)
{ 
  height = heightIn;
}
/**
*@return displays diameter when method is called.
* Accepts no parameters and returns double value
* for diameter calculated using radius.
*/ 
public double diameter()
{
  return radius * 2;
}
/**
*@return displays circumference when method is called.
* Accepts no parameters and returns double value 
* for circumference calculated using Math.PI and radius.
*/ 
public double circumference()
{
  return Math.PI * radius * 2;
}
/**
*@return displays area when method is called.
* Accepts no parameters and returns double value
* for surface area calculated using Math.PI, radius, and height.
*/ 
public double area()
{
  return 2 * Math.PI * radius * radius + 2 * Math.PI * radius * height;
}
/**
*@return displays volume when method is called.
* Accepts no parameters and returns double value
* for volume calculated using Math.PI, radius, and height.
*/ 
public double volume()
{
  return Math.PI * radius * radius * height;
}
/**
*@return displays cylinder information.
* Returns a string containing the information about
* the cylinder object.
*/ 
public String toString()
{
  DecimalFormat fmt = new DecimalFormat("#,##0.0##");

  return   "\"" + label
           + "\" is a cylinder with radius = " +     fmt.format(getRadius())
           + " units and height = " + fmt.format(getHeight()) + " units," 
           + "\nwhich has diameter = " + fmt.format(diameter())  
           + " units, circumference = " + fmt.format(circumference()) 
           + " units,"
           + "\narea = " + fmt.format(area()) + " square units,"
           + " and volume = " + fmt.format(volume()) + " cubic units.";
 }
 }

我需要为每种方法编写测试用例，但我不确定如何做到这一点。我试过了..

@Test public void getLabelTest() {
      Cylinder c = new String("Cyl");

但我得到incompatible type error。任何帮助将不胜感激。

Answer 1

由于您使用的是@Test注释，我假设您应该使用JUnit测试。

检查here，了解它是如何完成的。

您正在尝试将字符串分配给您的Cylinder，不兼容类型错误来自哪里。我认为你打算使用

Cylinder c = new Cylinder("Cyl", 1.0, 1.0); // label = "Cyl", radius = 1.0, height = 1.0

通常，您在一个名为 JUnit Test Case 的单独Java文件中创建（JUnit）-Test，并且您将为使用@Test注释的方法创建单个测试。

这是一个简单的例子，这个 JUnit测试用例的外观如何（与你的setLabel方法有关）：

import static org.junit.Assert.*;

import org.junit.Before;
import org.junit.Test;

public class JUnitTest {

    private Cylinder c;

    @Before
    public void setUp() {
        // initializing Cylinder instance to work on
        c = new Cylinder("Cyl", 1.0, 1.0);
    }

    @Test
    public void setLabelTest() {
        // parameter is null, return value should be false
        assertFalse(c.setLabel(null));
        // parameter is NOT null, return value should be true
        assertTrue(c.setLabel("Foo"));
    }
}

同时检查Assert doc是否有不同的断言。

Java测试用例

1 个答案: