JavaCUP 是 Java 语言实现的 CUP 解析器生成器。

示例代码：

// Simple Example Scanner Class 
// scanner.java
import java_cup.runtime.*;
import java.io.*;
//import sym;

public class scanner implements java_cup.runtime.Scanner {
  /* single lookahead character */
  protected static int next_char;
  // since cup v11 we use SymbolFactories rather than Symbols
  private SymbolFactory sf = new DefaultSymbolFactory();
  private static FileReader fileReader;
  public scanner(FileReader fr){
      this.fileReader=fr;
  }
  /* advance input by one character */
  protected static void  advance()
    throws java.io.IOException
    { next_char = fileReader.read(); }

  /* initialize the scanner */
  public static void init()
    throws java.io.IOException
    { advance(); }

  /* recognize and return the next complete token */
  public Symbol next_token()
    throws java.io.IOException
    {
      for (;;)
        switch (next_char)
      {
        case '0': case '1': case '2': case '3': case '4': 
        case '5': case '6': case '7': case '8': case '9': 
          /* parse a decimal integer */
          int i_val = 0;
          do {
            i_val = i_val * 10 + (next_char - '0');
            advance();
          } while (next_char >= '0' && next_char