编写程序统计一个输入的Java源码中关键字（区分大小写）出现的次数。说明如下： Java中共有53个关键字（自行百度） 从键盘输入一段源码，统计这段源码中出现的关键字的数量 注释中出现的关键字不用统计 字符串中出现的关键字不用统计 统计出的关键字及数量按照关键字升序进行排序输出 未输入源码则认为输入非法 输入格式: 输入Java源码字符串，可以一行或多行，以exit行作为结束标志 输出格式: 当未输入源码时，程序输出Wrong Format 当没有统计数据时，输出为空 当有统计数据时，关键字按照升序排列，每行输出一个关键字及数量，格式为数量\t关键字，java实现

下面是一个示例Java程序，用于统计输入的Java源码中出现的关键字的数量，并按照关键字升序进行排序输出：

import java.util.*;

public class KeywordCounter {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String line;
        StringBuilder builder = new StringBuilder();
        while (!(line = scanner.nextLine()).equals("exit")) {
            builder.append(line);
            builder.append("\n");
        }
        String sourceCode = builder.toString();
        if (sourceCode.trim().isEmpty()) {
            System.out.println("Wrong Format");
            return;
        }
        String[] keywords = new String[] {
                "abstract", "assert", "boolean", "break", "byte", "case", "catch", "char", "class", "const",
                "continue", "default", "do", "double", "else", "enum", "extends", "final", "finally", "float",
                "for", "goto", "if", "implements", "import", "instanceof", "int", "interface", "long", "native",
                "new", "package", "private", "protected", "public", "return", "short", "static", "strictfp",
                "super", "switch", "synchronized", "this", "throw", "throws", "transient", "try", "void",
                "volatile", "while"
        };
        Map<String, Integer> keywordCountMap = new TreeMap<>();
        int startPos = 0;
        boolean inString = false;
        boolean inComment = false;
        while (startPos < sourceCode.length()) {
            int nextPos;
            if (inString) {
                nextPos = sourceCode.indexOf("\"", startPos + 1);
                if (nextPos == -1) {
                    break;
                }
            } else if (inComment) {
                nextPos = sourceCode.indexOf("*/", startPos + 1);
                if (nextPos == -1) {
                    break;
                }
                inComment = false;
                startPos = nextPos + 2;
                continue;
            } else {
                nextPos = sourceCode.length();
                int commentStartPos = sourceCode.indexOf("/*", startPos);
                int lineCommentStartPos = sourceCode.indexOf("//", startPos);
                if (lineCommentStartPos != -1 && (commentStartPos == -1 || lineCommentStartPos < commentStartPos)) {
                    nextPos = lineCommentStartPos;
                }
                if (commentStartPos != -1 && (lineCommentStartPos == -1 || commentStartPos < lineCommentStartPos)) {
                    nextPos = commentStartPos;
                    inComment = true;
                }
                for (String keyword : keywords) {
                    int keywordPos = sourceCode.indexOf(keyword, startPos);
                    if (keywordPos != -1 && keywordPos < nextPos) {
                        int endPos = keywordPos + keyword.length();
                        if (endPos == sourceCode.length() || !Character.isJavaIdentifierPart(sourceCode.charAt(endPos))) {
                            keywordCountMap.put(keyword, keywordCountMap.getOrDefault(keyword, 0) + 1);
                        }
                    }
                }
            }
            startPos = nextPos + 1;
        }
        for (Map.Entry<String, Integer> entry : keywordCountMap.entrySet()) {
            System.out.printf("%d\t%s\n", entry.getValue(), entry.getKey());
        }
    }
}

该程序首先从标准输入读取输入的Java源码，然后使用一个字符串数组保存Java的关键字。接着，程序使用一个`Map`对象统计源码中出现的每个关键字的数量，并在统计时忽略了注释和字符串中出现的关键字。最后，程序按照关键字升序进行排序输出统计结果。