Java 调用给我带来问题的类(坏类-类文件包含错误的类)
下面是我得到的错误:Java 调用给我带来问题的类(坏类-类文件包含错误的类),java,Java,下面是我得到的错误: airfoilNumber.java:5: error: cannot access airfoil private airfoil myAirfoil = new airfoil(); ^ bad class file: ./airfoil.class class file contains wrong class: airfoil.airfoil Please remove or make sure it appea
airfoilNumber.java:5: error: cannot access airfoil
private airfoil myAirfoil = new airfoil();
^
bad class file: ./airfoil.class
class file contains wrong class: airfoil.airfoil
Please remove or make sure it appears in the correct subdirectory of the classpath.
这是我的主要课程:
import java.util.Scanner;
public class airfoilNumber
{
private airfoil myAirfoil = new airfoil();
public static void main(String[] args)
{
Scanner numNaca1 = new Scanner(System.in); //make a scanner and prompt user for their desired NACA number
System.out.println("What is your NACA number?"); //prompt user for NACA number
int numNaca = numNaca1.nextInt(); //apply the number to numNaca
new airfoil(numNaca); //call out airfoil class and run calculations
}
}
这是我的计算器课:
package airfoil;
import java.text.DecimalFormat;
import java.text.NumberFormat;
public class airfoil
{
private static final int numOfCoord = 250;
double dx = 1
.0 / numOfCoord;
private double m; // maximum camber in % of chord
private double p; // chordwise position of max ord., 10th of chord
private double t; // thickness in % of the cord
private String nacaNum; // NACA number - 4 digits
private double[][] coordinates; // Coordinates of the upper half or lower half of the airfoil
private double[][] meanLine; // mean line coordinates
public airfoil(String number) {
nacaNum = number;
m = Double.parseDouble(nacaNum.substring(0,1)) / 100.0;
p = Double.parseDouble(nacaNum.substring(1,2)) / 10.0;
t = Double.parseDouble(nacaNum.substring(2,4)) / 100.0;
meanLine = new double[2][numOfCoord]; // x values row 0, y values row 1
// x upper = row 0,
// y upper = row 1,
// x lower = row 2,
// y lower = row 3
coordinates = new double [4][numOfCoord];
System.out.println("NACA: " + nacaNum);
System.out.println("Number of coordinates: " + numOfCoord);
calcMeanLine();
calcAirfoil();
}
/*
* Calculates the values for the mean line forward of the maximum
* ordinate and aft of the maximum ordinate.
*/
private void calcMeanLine() {
double x = dx;
int j = 0;
// fwd of max ordinate
while (x <= p) {
meanLine[0][j] = x;
meanLine[1][j] = (m / (p * p))*(2*p*x - (x*x));
x += dx;
j++;
}
// aft of max ordinate
while (x <= 1.0 + dx) {
meanLine[0][j] = x;
meanLine[1][j] = (m / ((1 - p) * (1 - p))) *
((1 - 2*p) + 2*p*x - x * x);
x += dx;
j++;
}
} // end calcMeanLine
/*
* Calculate the upper and lower coordinates of the airfoil surface.
*/
private void calcAirfoil() {
double theta; // arctan(dy_dx)
double dy; // derivative of mean line equation
double yt, ml; // thickness and meanline values, respectively
double x = dx; // x-value w.r.t. chord
int j = 0; // counter for array
// calculate upper/lower surface coordinates fwd of max ordinate
while (x <= p) {
dy = (m / (p*p)) * (2*p - 2*x);
theta = Math.atan(dy);
yt = thicknessEQ(x);
ml = meanLine[1][j];
// upper surface coordinates;
coordinates[0][j] = x - yt * Math.sin(theta);
coordinates[1][j] = ml + yt * Math.cos(theta);
// lower surface coordinates
coordinates[2][j] = x + yt*Math.sin(theta);
coordinates[3][j] = ml - yt * Math.cos(theta);
x += dx;
j++;
}
// calculate the coordinates aft of max ordinate
while (x <= 1.0 + dx) {
dy = (m / ((1 - p) * (1 - p))) * ((2 * p) - (2 * x));
theta = Math.atan(dy);
yt = thicknessEQ(x);
ml = meanLine[1][j];
// upper surface coordinates;
coordinates[0][j] = x - yt * Math.sin(theta);
coordinates[1][j] = ml + yt * Math.cos(theta);
// lower surface coordinates
coordinates[2][j] = x + yt * Math.sin(theta);
coordinates[3][j] = ml - yt * Math.cos(theta);
x += dx;
j++;
}
System.out.println("j = " + j);
} // end calcAirfoil
/*
* Thickness equation
*/
private double thicknessEQ(double x) {
return ((t / 0.2) * (0.2969 * Math.sqrt(x) - (0.126 * x) -
(0.3526 * x * x) + (0.28430 * x * x * x) -
(0.1015 * x * x * x * x)));
}
public String toString() {
String str = "";
NumberFormat df = new DecimalFormat("0.0000");
System.out.println("Xu\tYu\tXl\tYl");
for (int j = 0; j < numOfCoord; j++) {
str += df.format(coordinates[0][j]) + "\t" +
df.format(coordinates[1][j]) + "\t" +
df.format(coordinates[2][j]) + "\t" +
df.format(coordinates[3][j]) + "\n";
}
return str;
}
/*
* Return the coordinates array
*/
public double[][] getCoordinates() { return coordinates; }
public int getSize() { return numOfCoord; }
} // end Airfoil class
package翼型;
导入java.text.DecimalFormat;
导入java.text.NumberFormat;
公共级机翼
{
私有静态最终整数NUMOFCORD=250;
双dx=1
.0/纽莫夫库德;
私有双m;//最大拱度,以弦的%为单位
私有双p;//最大值的弦向位置,第10个弦
专用双t;//跳线的厚度(以百分比为单位)
私有字符串nacaNum;//NACA数字-4位
私有双[][]坐标;//机翼上半部分或下半部分的坐标
私有双[][]平均线;//平均线坐标
公共机翼(字符串编号){
nacaNum=数量;
m=Double.parseDouble(nacaNum.substring(0,1))/100.0;
p=Double.parseDouble(nacaNum.substring(1,2))/10.0;
t=Double.parseDouble(nacaNum.substring(2,4))/100.0;
平均线=新的双精度[2][numOfCoord];//x值第0行,y值第1行
//x上限=第0行,
//y上=第1行,
//x下=第2行,
//y下=第3行
坐标=新的双[4][numOfCoord];
System.out.println(“NACA:+nacaNum”);
System.out.println(“坐标数:+numOfCoord”);
calcMeanLine();
跟骨();
}
/*
*计算最大值前的平均线值
*最大纵坐标的纵坐标和纵坐标。
*/
私有void calcMeanLine(){
双x=dx;
int j=0;
//最大纵坐标fwd
而(x误差在:
new airfoil(numNaca); //call out airfoil class and run calculations
删除此行并呼叫:
myAirfoil(numNaca);
新的翼型使你的类的新实例,而不是运行计算。
代码中存在新实例,请参见第行:
private airfoil myAirfoil = new airfoil();
这是我的机翼。你有以下的等级结构:
package airfoil;
public class airfoil {
...
}
这需要像这样反映在文件系统上:
MyProject Project's top level directory
+-airfoilNumber.java
+-airfoil directory for "airfoil" package
+-airfoil.java
此外,您还需要在翼型编号
类中导入翼型。翼型
:
import airfoil.airfoil;
public class airfoilNumber {
}
通过此设置,您可以使用
C:> javac *.java
作为旁注,类名应该以大写字母开头。我没有回答这个问题,因为类
定义与其包含的文件之间的大小写不匹配。java
文件可能会导致其他难以跟踪的问题,至少在MS Windows上是如此
完成后,您需要修复翼型
类的构造函数。目前只有一个构造函数接受字符串
参数,但您可以按如下方式调用它:
private airfoil myAirfoil = new airfoil();
// does not compile - no non-arg constructor available
...
new airfoil(numNaca);
// does not compile - numNaca is int, constructor expects String
你已经弄乱了你的目录结构。你的类aivoril
需要放在一个包中(在文件系统上是一个子目录)翼型
。它在一个包中。在导入任何东西之前,我将它放在包翼型中的顶部。我没有做对吗?是的,它在一个包中,但也在一个名为翼型的子目录中。你应该将你的类放在一个包中,并使你的类名以大写字母开头。你在问题中读到错误在吗私人翼型我的翼型=新翼型();
?我不知道paths和他的项目中的其他人有什么问题,我在“新翼型(numNaca);”中看到了明显的错误,仅此而已。是的,“私人翼型我的翼型=新翼型()”仍然存在同样的问题谢谢!包中的主要类是什么?翼型编号?不是翼型?它告诉我包翼型不存在。我在翼型编号中添加了包翼型
,因为现在它告诉我在“翼型”的每次迭代中都找不到符号在翼型编号类中。否否,您的翼型编号
类位于默认包中(否包
语句)。您必须具有反映包结构的目录结构。(请注意,不鼓励使用默认包,但您现在应该首先关注如何编译当前源代码,然后再修复其他内容).好的,谢谢。它现在编译得很好。我对扫描文件做了一些改动,使其与计算器类相适应,现在编译得很好。计算器类给了我一个问题-线程“main”java.lang.NoClassDefFoundError中的异常:
,正如您所说,我通过从我的主类中删除包来修复它.现在一切都好了.谢谢你的帮助。
private airfoil myAirfoil = new airfoil();
// does not compile - no non-arg constructor available
...
new airfoil(numNaca);
// does not compile - numNaca is int, constructor expects String