[Java知识库]Java实验-03 Java 字符串处理提取关键字，方法，变量，操作符

实验要求

要求对一个 Java 程序进行简单的词法分析，找出其中用到的关键字、变量类型、变量名、方
法名以及操作运算符，并分别打印出来。
注意
考虑如果 (、{ 字符与关键字或变量名相连的情况下该怎么处理，尽可能将代码写完善。

挺简单的，用正则一下就出来了，直接放代码吧
基本上都考虑到了吧qaq，方法的话默认大家都用public了，不考虑其他情况

package exp03;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class CodeAnalysis {
    public static void main(String[] args) {
        String fileName = "C:\\Users\\CrazyBin\\IdeaProjects\\Exp03\\src\\exp03\\codeDemo";
        String regexKeyWords = "abstract|assert|boolean|break|case|catch|"
                + "class|const|continue|default|do|double|else"
                + "|extends|false|final|finally|for|goto|if|implements|"
                + "import|instanceof|interface|native|new|null|"
                + "package|privat|protected|public|return|static|"
                + "strictfp|super|switch|synchronized|this|throw|throws|true|"
                + "transient|try|void|volatile|while";
        String regexVariableType = "int|double|float|enum|long|byte|boolean|char|String|short";
        String regexMethod = "(public\\s+)?(static\\s+)?\\w+(\\[\\])?\\s+\\w+(\\s)?\\((\\w+(\\[\\])?\\s+\\w+(\\s+)?\\,)*(\\w+(\\[\\])?\\s+\\w+)?(\\s+)*\\)\\s{1}";
        String regexVariable = "(private\\s+)?(static\\s+)?(int|double|float|enum|long|byte|boolean|char|String|short)(\\[\\])?\\s+\\S";
        String regexOperator = "(\\+|\\-|\\*|\\/)";
        StringBuilder stringBuilder = new StringBuilder();
        try {
            FileInputStream inputStream = new FileInputStream(fileName);
            BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
            int temp = 0;
            while (temp != -1) {
                temp = bufferedInputStream.read();
                stringBuilder.append((char) temp);
            }
            System.err.println("程序的关键字，变量类型，方法，变量名，操作符统计如下:");
            bufferedInputStream.close();
            inputStream.close();
            search(regexKeyWords,stringBuilder);
            search(regexVariableType,stringBuilder);
            search(regexMethod,stringBuilder);
            search(regexVariable,stringBuilder);
            search(regexOperator,stringBuilder);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static void search(String regex,StringBuilder stringBuilder)
    {
        Pattern pattern=Pattern.compile(regex);
        Matcher matcher=pattern.matcher(stringBuilder);
        while(matcher.find())
        {
            System.out.println(matcher.group());
        }
    }
}

运行截图

截了一部分