我有一个java类SortTest，它包含实现接口Sorter的子类。我一直在Eclipse中工作，但我需要在UNIX中编译和运行，所以我可以传入命令行参数。所以我一直在访问我的.java文件所在的目录
cd Documents/workspace/csc220/src/prog09
然后我使用
编译我的类和接口javac Sorter.java SortTest.java
没有问题。但是，当我尝试使用
运行时java SortTest 10 //10 is an arbitrary argument
我收到此错误：
Exception in thread "main" java.lang.NoClassDefFoundError: SortTest/java
Caused by: java.lang.ClassNotFoundException: SortTest.java
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
我已经查看了其他线程，似乎表明这可能是Sorter的编译时/运行时可用性的问题，但错误仅提到SortTest，我发现这令人困惑。我该如何解决这个问题？它不依赖于我的实际代码，是吗？
编辑：这是SortTest.java的代码：
package prog09;
import java.util.Random;
public class SortTest<E extends Comparable<E>> {
public void test (Sorter<E> sorter, E[] array) {
E[] copy = array.clone();
sorter.sort(copy);
System.out.println(sorter);
for (int i = 0; i < copy.length; i++)
System.out.print(copy[i] + " ");
System.out.println();
}
public static void main (String[] args) {
Integer[] array = { 3, 1, 4, 1, 5, 9, 2, 6 };
int size = 0;
try{
size = Integer.parseInt(args[0]);
}catch(NumberFormatException e){
System.out.println("Your argument was not an integer! Quitting program...");
return;
}
if (args.length > 0) {
// Print out command line argument if there is one.
System.out.println("args[0] = " + args[0]);
// Create a random object to call random.nextInt() on.
Random random = new Random(0);
// Make array.length equal to args[0] and fill it with random
// integers:
for(int i = 0; i < size; i++){
array[i] = random.nextInt();
}
}
//print out the array if array.length <= 100
if(array.length <= 100){
System.out.printf("[ ");
for(int i = 0; i < array.length; i++){
System.out.printf(array[i]+" ");
}
System.out.printf("]");
}
SortTest<Integer> tester = new SortTest<Integer>();
tester.test(new InsertionSort<Integer>(), array);
tester.test(new HeapSort<Integer>(), array);
tester.test(new QuickSort<Integer>(), array);
tester.test(new MergeSort<Integer>(), array);
}
}
class InsertionSort<E extends Comparable<E>>
implements Sorter<E> {
public void sort (E[] array) {
for (int n = 0; n < array.length; n++) {
E data = array[n];
int i = n;
// while array[i-1] > data move array[i-1] to array[i] and
// decrement i
while(i > 0 && array[i-1].compareTo(data) > 0){
array[i] = array[i-1];
i--;
}
array[i] = data;
}
}
}
class HeapSort<E extends Comparable<E>>
implements Sorter<E> {
private E[] array;
private void swap (int i, int j) {
E data = array[i];
array[i] = array[j];
array[j] = data;
}
public void sort (E[] array) {
this.array = array;
for (int i = parent(array.length - 1); i >= 0; i--)
swapDown(i, array.length - 1);
for (int n = array.length - 1; n >= 0; n--) {
swap(0, n);
swapDown(0, n - 1);
}
}
public void swapDown (int root, int end) {
// Calculate the left child of root.
int leftChild = 2*root + 1;
// while the left child is still in the array
// calculate the right child
// if the right child is in the array and
// it is bigger than than the left child
// bigger child is right child
// else
// bigger child is left child
// if the root is not less than the bigger child
// return
// swap the root with the bigger child
// update root and calculate left child
while(leftChild < end){
int rightChild = 2*root + 2;
int bigChild;
if(rightChild < end && array[rightChild].compareTo(array[leftChild]) > 0){
bigChild = rightChild;
}else{
bigChild = leftChild;
}
if(!(array[root].compareTo(array[bigChild]) < 0)){
return;
}
swap(root, bigChild);
root = bigChild;
leftChild = 2*root + 1;
}
}
private int left (int i) { return 2 * i + 1; }
private int right (int i) { return 2 * i + 2; }
private int parent (int i) { return (i - 1) / 2; }
}
class QuickSort<E extends Comparable<E>>
implements Sorter<E> {
private E[] array;
private void swap (int i, int j) {
E data = array[i];
array[i] = array[j];
array[j] = data;
}
public void sort (E[] array) {
this.array = array;
sort(0, array.length-1);
}
private void sort(int left, int right) {
if (left >= right)
return;
swap(left, (left + right) / 2);
E pivot = array[left];
int a = left + 1;
int b = right;
while (a <= b) {
// Move a forward if array[a] <= pivot
if(!(array[a].compareTo(pivot) > 0)){
a++;
}else
// Move b backward if array[b] > pivot
if(array[b].compareTo(pivot) > 0){
b--;
}else
// Otherwise swap array[a] and array[b]
swap(a,b);
}
swap(left, b);
sort(left, b-1);
sort(b+1, right);
}
}
class MergeSort<E extends Comparable<E>>
implements Sorter<E> {
private E[] array, array2;
public void sort (E[] array) {
this.array = array;
array2 = array.clone();
sort(0, array.length-1);
}
private void sort(int left, int right) {
if (left >= right)
return;
int middle = (left + right) / 2;
sort(left, middle);
sort(middle+1, right);
int i = left;
int a = left;
int b = middle+1;
while (a <= middle || b <= right) {
// If both a <= middle and b <= right
// copy the smaller of array[a] or array[b] to array2[i]
// Otherwise just copy the remaining elements to array2
if(a <= middle && b <= right){
if(array[a].compareTo(array[b]) < 0){
array2[i] = array[a];
a++;
}else{
array2[i] = array[b];
b++;
}
i++;
}else{
if(a > middle)
System.arraycopy(array, b, array2, i, array.length-b-1);
else
System.arraycopy(array, a, array2, i, middle-a+1);
break;
}
}
System.arraycopy(array2, left, array, left, right - left + 1);
}
}
这是Sorter.java：
package prog09;
public interface Sorter<E extends Comparable<E>> {
void sort (E[] array);
}
这是我从父目录运行java -cp prog09 SortTest时收到的错误消息：
Exception in thread "main" java.lang.NoClassDefFoundError: SortTest (wrong name: prog09/SortTest)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
答案 0 :(得分：1)
package prog9语句。ls -l SortTest.class位于当前目录中。java命令是否正在运行/usr/bin/java（您说您是在Mac上并且darwin的JAVA_HOME管理环境稍微复杂）而不是其他任何事情。java -classpath . SortTest并告诉我们会发生什么。 OP通过删除package prog09将两个文件放入默认命名空间，并且＃34;工作。＆＃34;
从命令行离开package prog09，可以执行此操作：
mkdir prog09
javac Sorter.java SortTest.java
mv Sorter.class SortTest.class prog09
java -classpath . prog09.SortTest