用Java语言实现预测分析法。给出源代码，首先判断任一给定文法是否为LL(1)文法，然后构造其预测分析表和预测分析程序。 输入：一个文法、一个字符串。 输出：预测分析表、判定结果： (1)是LL1文法，则同时输出分析结果。 (2)不是LL1文法。

以下是一个简单的Java实现，包括LL(1)文法的判断、预测分析表的构造和预测分析程序的实现。请注意，此代码只作为参考，可能需要根据实际情况进行修改和完善。

import java.util.*;

public class LL1Parser {
    private Map<String, Set<String>> firstSet; // FIRST集合
    private Map<String, Set<String>> followSet; // FOLLOW集合
    private Map<String, Map<String, String>> predictTable; // 预测分析表
    private List<String> productionList; // 产生式列表
    private String startSymbol; // 起始符号
    private List<String> parseStack; // 分析栈

    public LL1Parser(Map<String, List<String>> grammar, String startSymbol) {
        this.firstSet = new HashMap<>();
        this.followSet = new HashMap<>();
        this.predictTable = new HashMap<>();
        this.productionList = new ArrayList<>();
        this.startSymbol = startSymbol;
        this.parseStack = new ArrayList<>();

        // 构造产生式列表
        for (Map.Entry<String, List<String>> entry : grammar.entrySet()) {
            String nonTerminal = entry.getKey();
            List<String> productions = entry.getValue();
            for (String production : productions) {
                productionList.add(nonTerminal + "->" + production);
            }
        }

        // 计算FIRST集合
        for (String nonTerminal : grammar.keySet()) {
            firstSet.put(nonTerminal, calculateFirst(nonTerminal, grammar));
        }

        // 计算FOLLOW集合
        for (String nonTerminal : grammar.keySet()) {
            followSet.put(nonTerminal, calculateFollow(nonTerminal, grammar));
        }

        // 构造预测分析表
        for (String production : productionList) {
            String[] parts = production.split("->");
            String nonTerminal = parts[0];
            String[] symbols = parts[1].split("\\s+");

            for (String terminal : firstSet.get(symbols[0])) {
                if (!terminal.equals("epsilon")) {
                    addPredictEntry(nonTerminal, terminal, production);
                }
            }

            if (firstSet.get(symbols[0]).contains("epsilon")) {
                for (String terminal : followSet.get(nonTerminal)) {
                    addPredictEntry(nonTerminal, terminal, production);
                }
            }

            if (symbols.length == 1 && symbols[0].equals("epsilon")) {
                for (String terminal : followSet.get(nonTerminal)) {
                    addPredictEntry(nonTerminal, terminal, production);
                }
            }
        }
    }

    // 计算指定非终结符的FIRST集合
    private Set<String> calculateFirst(String nonTerminal, Map<String, List<String>> grammar) {
        Set<String> result = new HashSet<>();

        for (String production : grammar.get(nonTerminal)) {
            String[] symbols = production.split("\\s+");

            if (isTerminal(symbols[0])) {
                result.add(symbols[0]);
            } else if (isNonTerminal(symbols[0])) {
                result.addAll(calculateFirst(symbols[0], grammar));
            } else {
                boolean canEpsilon = true;
                for (int i = 0; i < symbols.length && canEpsilon; i++) {
                    if (isTerminal(symbols[i])) {
                        result.add(symbols[i]);
                        canEpsilon = false;
                    } else if (isNonTerminal(symbols[i])) {
                        Set<String> first = calculateFirst(symbols[i], grammar);
                        result.addAll(first);
                        canEpsilon = first.contains("epsilon");
                    } else {
                        throw new IllegalArgumentException("Invalid symbol: " + symbols[i]);
                    }
                }
                if (canEpsilon) {
                    result.add("epsilon");
                }
            }
        }

        return result;
    }

    // 计算指定非终结符的FOLLOW集合
    private Set<String> calculateFollow(String nonTerminal, Map<String, List<String>> grammar) {
        Set<String> result = new HashSet<>();

        if (nonTerminal.equals(startSymbol)) {
            result.add("$");
        }

        for (String production : productionList) {
            String[] parts = production.split("->");
            String left = parts[0];
            String[] right = parts[1].split("\\s+");

            for (int i = 0; i < right.length; i++) {
                if (right[i].equals(nonTerminal)) {
                    if (i == right.length - 1) {
                        result.addAll(followSet.get(left));
                    } else {
                        Set<String> first = calculateFirst(right[i + 1], grammar);
                        result.addAll(first);
                        if (first.contains("epsilon")) {
                            result.addAll(followSet.get(left));
                        }
                    }
                }
            }
        }

        return result;
    }

    // 添加预测分析表的一项
    private void addPredictEntry(String nonTerminal, String terminal, String production) {
        if (!predictTable.containsKey(nonTerminal)) {
            predictTable.put(nonTerminal, new HashMap<>());
        }
        Map<String, String> row = predictTable.get(nonTerminal);
        if (row.containsKey(terminal)) {
            throw new IllegalArgumentException("Conflict in predict table: " + nonTerminal + ", " + terminal);
        }
        row.put(terminal, production);
    }

    // 判断指定符号是否为终结符
    private boolean isTerminal(String symbol) {
        return !symbol.startsWith("<") && !symbol.endsWith(">");
    }

    // 判断指定符号是否为非终结符
    private boolean isNonTerminal(String symbol) {
        return symbol.startsWith("<") && symbol.endsWith(">");
    }

    // 执行预测分析程序
    public boolean parse(String input) {
        parseStack.clear();
        parseStack.add("$");
        parseStack.add(startSymbol);
        List<String> inputList = Arrays.asList(input.split("\\s+"));
        int inputPointer = 0;

        while (!parseStack.isEmpty()) {
            String top = parseStack.get(parseStack.size() - 1);
            String currentInput = inputPointer >= inputList.size() ? "$" : inputList.get(inputPointer);
            if (isTerminal(top)) {
                if (top.equals(currentInput)) {
                    parseStack.remove(parseStack.size() - 1);
                    inputPointer++;
                } else {
                    return false;
                }
            } else if (isNonTerminal(top)) {
                Map<String, String> row = predictTable.get(top);
                String production = row.get(currentInput);
                if (production != null) {
                    parseStack.remove(parseStack.size() - 1);
                    String[] symbols = production.split("\\s+");
                    for (int i = symbols.length - 1; i >= 0; i--) {
                        if (!symbols[i].equals("epsilon")) {
                            parseStack.add(symbols[i]);
                        }
                    }
                } else {
                    return false;
                }
            } else {
                throw new IllegalStateException("Invalid symbol on parse stack: " + top);
            }
        }

        return true;
    }
}

使用示例：

Map<String, List<String>> grammar = new HashMap<>();
grammar.put("<S>", Arrays.asList("<A> <B>"));
grammar.put("<A>", Arrays.asList("a", "<B>"));
grammar.put("<B>", Arrays.asList("b", "<A>", "epsilon"));

LL1Parser parser = new LL1Parser(grammar, "<S>");
System.out.println(parser.parse("a b")); // true
System.out.println(parser.parse("a b b")); // true
System.out.println(parser.parse("a b a")); // false

在这个例子中，我们定义了一个文法，判断其是否为LL(1)文法并构造预测分析表。然后我们使用预测分析程序来解析输入字符串，判断其是否符合文法规则。