我正在尝试从命令提示符运行java文件。当我在NetBeans IDE中运行该程序时，它工作正常。不幸的是，我需要能够从命令提示符运行它。我有两节课。我将包含所有代码，以防它相关。我找了这个问题的帖子，但我没有看到任何似乎可以解决我的问题。在解释事情时，请这样做，好像和那些对此知之甚少的人交谈，因为情况确实如此。
package projectbeng;
import java.util.Scanner;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.File;
import java.io.IOException;
public class DataRecover {
public static void main(String[] args) throws Exception {
//Create a Scanner for the user
Scanner sc = new Scanner(System.in);
System.out.print("Enter file name to process: ");
File fileName = new File(sc.nextLine() + ".txt"); //Do not include the .txt extension
if(!fileName.exists()){ //does not exist
throw new IOException("File \"" + fileName + "\" not found.");
}
System.out.println("\nProcessing file: " + fileName + "\n----------------------------------------");
BufferedReader br = new BufferedReader(new FileReader(fileName));
int lineCount = 0; //assumes file does not end with a new line character
int tripleLineCount = 0;
int tripleCount = 0;
String line = "";
//Read data from file
while((line = br.readLine()) != null){ //has another line in the file
lineCount++;
if(!line.equals("")) { //is not a blank line
Triple triples = extractTriples(line);
if(triples.getHasTriple()) { //line contains triples
System.out.println(triples.getTriples());
tripleLineCount++;
}
for(int j = 0; j < triples.getTriples().length(); j++) {
if(triples.getTriples().charAt(j) == '(') tripleCount++;
}
}
}
//prints out the summary of the file
System.out.println("\nSummary\n----------------------------------------");
System.out.println("Total lines: " + lineCount);
System.out.println("Lines containing triples: " + tripleLineCount);
System.out.println("Total number of triples: " + tripleCount);
}
/*Given a string, returns a Triple with a string containing the triples (if any) and a boolean stating whether
or not it contains a triple.
Assumptions:
1.) If a '-' sign is found, it has been added. If preceeding a number (for example -32), the number is 32 where
the '-' sign is simply garbage.
2.) If a '.' is found in a number (for example 2.32), the potential integers are 2 and 32 where the '.' is
garbage.
3.) For part c, if the first valid character found is a letter, this will always be the real triple. It does not
matter whether or not it is part of a word (for example, if it comes across "Dog a", 'D' will be the triple.)
4.) The strings "<null>", "<cr>", "<lf>", and "<eof>" as well as multi-digit numbers (ex. 32) count as single
characters. Thus, they cannot be broken up (no garbage in between the characters).
*/
static Triple extractTriples(String str) {
/*Grammar:
Triple is in form (a,b,c) where a is either a non-negative integer or the string "<null>", b is a
non-negative integer where b <= a (b must be 0 if a is <null>), and c is either an individual letter
(upper or lower case), period, colon, semicolon, or one of the three strings "<cr>", "<lf>", or "<eof>".
state == 0 ==> needs left parenthesis
state == 1 ==> needs right parenthesis
state == 2 ==> needs comma
state == 3 ==> needs a
state == 4 ==> needs b
state == 5 ==> needs c
*/
int state = 0;
int a = -1;
int b = -1;
String triples = "";
String tempTriples = "";
for(int i = 0; i < str.length(); i++) {
if(str.charAt(i) == '.' || str.charAt(i) == ':' || str.charAt(i) == ';' || str.charAt(i) == '<' ||
(str.charAt(i) >= 'a' && str.charAt(i) <= 'z') || (str.charAt(i) >= 'A' && str.charAt(i) <= 'Z')
|| (str.charAt(i) >= '0' && str.charAt(i) <= '9') || str.charAt(i) == ',' ||
str.charAt(i) == '(' || str.charAt(i) == ')') {
if(state == 0) {
if(str.charAt(i) == '(') {
tempTriples = str.substring(i, i+1);
state = 3;
}
}else if(state == 1) {
if(str.charAt(i) == ')') {
triples = triples + tempTriples + str.substring(i, i+1) + " ";
tempTriples = "";
state = 0;
a = -1;
b = -1;
}
}else if(state == 2) {
if(str.charAt(i) == ',') {
tempTriples = tempTriples + str.substring(i, i+1);
if(b != -1) state = 5;
else state = 4;
}
}else if(state == 3) {
if(str.charAt(i) >= '0' && str.charAt(i) <= '9') {
int j = i;
while(j < str.length() && str.charAt(j) >= '0' && str.charAt(j) <= '9') j++;
a = Integer.parseInt(str.substring(i, j));
i = j - 1;
tempTriples = tempTriples + a;
state = 2;
}else if(str.length() > i + 5 && str.substring(i, i+6).equals("<null>")) {
a = 0;
tempTriples = tempTriples + str.substring(i, str.indexOf(">", i)+1);
i = str.indexOf(">", i);
state = 2;
}
}else if(state == 4) {
if(str.charAt(i) >= '0' && str.charAt(i) <= '9') {
int j = i;
while(j < str.length() && str.charAt(j) >= '0' && str.charAt(j) <= '9') j++;
b = Integer.parseInt(str.substring(i, j));
i = j - 1;
if(b <= a) {
tempTriples = tempTriples + b;
state = 2;
}else b = -1;
}
}else if(state == 5) {
if(str.charAt(i) == '.' || str.charAt(i) == ':'||(str.charAt(i) <= 'z' && str.charAt(i) >= 'a')
|| str.charAt(i) == ';' || (str.charAt(i) <= 'Z' && str.charAt(i) >= 'A')) {
tempTriples = tempTriples + str.substring(i, i+1);
state = 1;
}else if((str.length() > i + 4 && str.substring(i, i+5).equals("<eof>")) ||
(str.length() > i + 3 && (str.substring(i, i+4).equals("<cr>") ||
str.substring(i, i+4).equals("<lf>")))) {
tempTriples = tempTriples + str.substring(i, str.indexOf(">", i)+1);
i = str.indexOf(">", i);
state = 1;
}else if(str.length() > i + 5 && str.substring(i, i+6).equals("<null>")) {
i = str.indexOf(">", i);
}
}
}
}
Triple triple = new Triple(true, triples);
if(triples.equals("")) triple.setHasTriple(false); //does not contain a triple
return triple;
}
}
package projectbeng;
class Triple {
boolean hasTriple = this.hasTriple;
String triple = this.triple;
//creates a new Triple
Triple(boolean newHasTriple, String newTriple){
this.hasTriple = newHasTriple;
this.triple = newTriple;
}
//returns whether or not Triple contains any triples
boolean getHasTriple() {
return hasTriple;
}
//returns the triples in Triple
String getTriples() {
return triple;
}
//changes the state of whether a Triple contains triples
void setHasTriple(boolean newHasTriple){
this.hasTriple = newHasTriple;
}
}
现在，我运行命令提示符，然后运行它，如图所示。还可以看到，创建了DataRecover和Triple的CLASS文件。
现在，我所做的是在C盘中创建了文件夹ProjectBenG。我将DataRecover.java和Triple.java文件放在此文件夹中。之后，我运行了命令提示符。我很好奇我需要做什么才能运行DataRecover。此外，您可以在文件夹中看到文件＆＃34; triplestest.txt＆＃34;。我希望这是我的代码中由DataRecover处理的文件。我还没有那么远，但如果有一些特定的东西我需要做才能让它工作，我会很感激这些信息
先谢谢大家的帮助。
答案 0 :(得分：0)
我认为问题在于你的项目结构。
我知道有两种选择。
1）删除每个文件顶部的两个包声明。然后，就像你一样，用
编译$ javac * .java
$ java DataRecover
2）保持包装正确并将其放在名为[包名称]的文件夹中（在您的案例中为projectbeng）。然后从父目录开始编译并运行。
$ mkdir projectbeng
$ cd projectbeng
$ javac * .java
$ cd ..
$ java projectbeng.DataRecover
请记住，如果您正在运行Windows，目录/文件夹管理将略有不同。让我知道它是怎么回事。
正如其他人所说，您可能想了解如何使用和分发jar文件。我猜你的教授喜欢简单地标记他的作业（我的也是如此）。无论如何......这个链接可能有助于http://www.skylit.com/javamethods/faqs/createjar.html
编辑：看你的截图，你似乎已经有了这个文件夹，尝试上移一个目录并运行
$ java projectbeng.DataRecover
