对项目中所写的Java代码进行计数，看总共写了多少行代码???

1.各种行的说明

在Java源程序中的行共有3种：

(1)代码行，可运行的Java源代码。例如：

 int n = 10; 

(2) 注释行，3种注释均可。例如：

 /**
  文档注释
 */

 /*
   多行注释
 */
 
 //单行注释

(3)空行，既无代码，也无注释；

                                                                                         

2.特殊行的处理方法

如果有以下行尾单行注释的情况，将该行判定为代码行。

 int number; //number表示人数 2 int n; /*n表示数量*/ 

如果有以下行尾多行注释的情况，第1行判定为代码行，第二行判定为注释行。

 int number; /* number为整型 2 表示人数 */ 

假设被分析程序源码无其他特殊情况，如:

 int /*人数*/ number; 

代码实现

代码中不使用正则表达式进行简化操作,而是使用逻辑判断.
思路还是先在给定的目录下递归寻找所有的java文件,将其加入到ArrayList中.用循环对ArrayList中每一个java文件分别统计总行数,注释行数,空白行数,代码行数.虽然可以只扫描一遍文件就能得到不同的行数,但是为了代码的耦合度和美观,每个统计都分开一个方法.

构造方法

ArrayList<File> fileList;
File root;
public CodeAnalyzer(String pathName) {
    root = new File(pathName);  //给定的目录
    fileList = new ArrayList<>(); //储存java文件
 }

递归搜索目录下的java文件

public void searchFiles() {
File[] files = root.listFiles();
int length = files.length;
for (int i = 0; i < length; i++) {
    if (files[i].isDirectory()) {
        root = files[i];
        searchFiles();
    } else {
        if (files[i].getName().endsWith(".java"))
            fileList.add(files[i]);
           }
    }
}

统计单个文件的空白行数

public int countBlanks(File file) throws IOException {
    BufferedReader input = new BufferedReader(new FileReader(file));
    int blanks = 0;
    String line = null;
    while ((line = input.readLine()) != null) {
        if (line.trim().equals("")) blanks++;
    }
    return blanks;
}

统计单个文件的注释行数

public int countComments(File file) throws IOException {
    BufferedReader input = new BufferedReader(new FileReader(file));
    int comments = 0;
    String line = null;
    while ((line = input.readLine()) != null) {
        line = line.trim();
        if (line.startsWith("//")) { //单行注释
            comments++;
        } else if (line.startsWith("/*")) { //多行及文档注释
            comments++;
            while (!line.endsWith("*/")) {
                line = input.readLine().trim();
                comments++;
            }
        } else if (line.contains("/*")) { //行尾多行注释
            line = input.readLine().trim();
            if (line.endsWith("*/")) comments++;
        }
    }
    return comments;
}

总的统计与输出

public void codeAnalyze() {
    double rowsCount = 0;
    double commentsCount = 0;
    double blanksCount = 0;
    double codesCount = 0;
    DecimalFormat df = new DecimalFormat("#.##");
    for (File file : fileList) {
        try {
            rowsCount += countRows(file);
            blanksCount += countBlanks(file);
            commentsCount += countComments(file);
            codesCount = rowsCount - blanksCount - commentsCount;
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    //输出结果
    System.out.println("源程序文件总行数:" + (int) rowsCount);
    System.out.println("代码行数:" + (int) codesCount + ",占" + df.format(codesCount / rowsCount*100) + "%");
    System.out.println("注释行数:" + (int) commentsCount + ",占" + df.format(commentsCount / rowsCount*100) + "%");
    System.out.println("空白行数:" + (int) blanksCount + ",占" + df.format(blanksCount / rowsCount*100) + "%");
}

主函数

public static void main(String[] args) {
    String pathName = "E:\1";
    CodeAnalyzer analyzer = new CodeAnalyzer(pathName);
    analyzer.searchFiles(); //搜索文件
    analyzer.codeAnalyze(); //统计文件
}

完整代码

import java.io.*;
import java.util.ArrayList;
import java.text.DecimalFormat;

public class CodeAnalyzer {
    ArrayList<File> fileList;
    File root;

    public CodeAnalyzer(String pathName) {
        root = new File(pathName);
        fileList = new ArrayList<>();
    }

    public void searchFiles() {
        File[] files = root.listFiles();
        int length = files.length;
        for (int i = 0; i < length; i++) {
            if (files[i].isDirectory()) {
                root = files[i];
                searchFiles();
            } else {
                if (files[i].getName().endsWith(".java"))
                    fileList.add(files[i]);
            }
        }
    }

    public void codeAnalyze() {
        double rowsCount = 0;
        double commentsCount = 0;
        double blanksCount = 0;
        double codesCount = 0;
        DecimalFormat df = new DecimalFormat("#.##");
        for (File file : fileList) {
            try {
                rowsCount += countRows(file);
                blanksCount += countBlanks(file);
                commentsCount += countComments(file);
                codesCount = rowsCount - blanksCount - commentsCount;
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        //输出结果
        System.out.println("源程序文件总行数:" + (int) rowsCount);
        System.out.println("代码行数:" + (int) codesCount + ",占" + df.format(codesCount / rowsCount * 100) + "%");
        System.out.println("注释行数:" + (int) commentsCount + ",占" + df.format(commentsCount / rowsCount * 100) + "%");
        System.out.println("空白行数:" + (int) blanksCount + ",占" + df.format(blanksCount / rowsCount * 100) + "%");
    }

    public int countRows(File file) throws IOException {
        BufferedReader input = new BufferedReader(new FileReader(file));
        int rows = 0;
        while (input.readLine() != null) {
            rows++;
        }
        return rows;
    }

    public int countBlanks(File file) throws IOException {
        BufferedReader input = new BufferedReader(new FileReader(file));
        int blanks = 0;
        String line = null;
        while ((line = input.readLine()) != null) {
            if (line.trim().equals("")) blanks++;
        }
        return blanks;
    }

    public int countComments(File file) throws IOException {
        BufferedReader input = new BufferedReader(new FileReader(file));
        int comments = 0;
        String line = null;
        while ((line = input.readLine()) != null) {
            line = line.trim();
            if (line.startsWith("//")) {//单行注释
                comments++;
            } else if (line.startsWith("/*")) { //多行及文档注释
                comments++;
                while (!line.endsWith("*/")) {
                    line = input.readLine().trim();
                    comments++;
                }
            } else if (line.contains("/*")) { //下行尾多行注释
                line = input.readLine().trim();
                if (line.endsWith("*/")) comments++;
            }

        }
        return comments;
    }

    public static void main(String[] args) {
        String pathName = "F:\Java\work";
        CodeAnalyzer analyzer = new CodeAnalyzer(pathName);
        analyzer.searchFiles();
        analyzer.codeAnalyze();
    }

}

测试结果

 参考项目： 代码计数器，内含有更多python打包exe文件，欢迎查阅！！！