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com.jayway.jsonpath.internal.path.PathCompiler Maven / Gradle / Ivy

package com.jayway.jsonpath.internal.path;

import com.jayway.jsonpath.InvalidPathException;
import com.jayway.jsonpath.Predicate;
import com.jayway.jsonpath.internal.CharacterIndex;
import com.jayway.jsonpath.internal.Path;
import com.jayway.jsonpath.internal.Utils;
import com.jayway.jsonpath.internal.filter.FilterCompiler;
import com.jayway.jsonpath.internal.function.ParamType;
import com.jayway.jsonpath.internal.function.Parameter;

import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import static java.lang.Character.isDigit;
import static java.util.Arrays.asList;

public class PathCompiler {

    private static final char DOC_CONTEXT = '$';
    private static final char EVAL_CONTEXT = '@';

    private static final char OPEN_SQUARE_BRACKET = '[';
    private static final char CLOSE_SQUARE_BRACKET = ']';
    private static final char OPEN_PARENTHESIS = '(';
    private static final char CLOSE_PARENTHESIS = ')';
    private static final char OPEN_BRACE = '{';
    private static final char CLOSE_BRACE = '}';

    private static final char WILDCARD = '*';
    private static final char PERIOD = '.';
    private static final char SPACE = ' ';
    private static final char TAB = '\t';
    private static final char CR = '\r';
    private static final char LF = '\n';
    private static final char BEGIN_FILTER = '?';
    private static final char COMMA = ',';
    private static final char SPLIT = ':';
    private static final char MINUS = '-';
    private static final char SINGLE_QUOTE = '\'';
    private static final char DOUBLE_QUOTE = '"';

    private final LinkedList filterStack;
    private final CharacterIndex path;

    private PathCompiler(String path, LinkedList filterStack){
        this(new CharacterIndex(path), filterStack);
    }

    private PathCompiler(CharacterIndex path, LinkedList filterStack){
        this.filterStack = filterStack;
        this.path = path;
    }

    private Path compile() {
        RootPathToken root = readContextToken();
        return new CompiledPath(root, root.getPathFragment().equals("$"));
    }

    public static Path compile(String path, final Predicate... filters) {
        try {
            CharacterIndex ci = new CharacterIndex(path);
            ci.trim();

            if(!( ci.charAt(0) == DOC_CONTEXT)  && !( ci.charAt(0) == EVAL_CONTEXT)){
                ci = new CharacterIndex("$." + path);
                ci.trim();
            }
            if(ci.lastCharIs('.')){
                fail("Path must not end with a '.' or '..'");
            }
            LinkedList filterStack = new LinkedList(asList(filters));
            return new PathCompiler(ci, filterStack).compile();
        } catch (Exception e) {
            InvalidPathException ipe;
            if (e instanceof InvalidPathException) {
                ipe = (InvalidPathException) e;
            } else {
                ipe = new InvalidPathException(e);
            }
            throw ipe;
        }
    }

    private void readWhitespace() {
        while (path.inBounds()) {
            char c = path.currentChar();
            if (!isWhitespace(c)) {
                break;
            }
            path.incrementPosition(1);
        }
    }

    private Boolean isPathContext(char c) {
        return (c == DOC_CONTEXT || c == EVAL_CONTEXT);
    }

    //[$ | @]
    private RootPathToken readContextToken() {

        readWhitespace();

        if (!isPathContext(path.currentChar())) {
            throw new InvalidPathException("Path must start with '$' or '@'");
        }

        RootPathToken pathToken = PathTokenFactory.createRootPathToken(path.currentChar());

        if (path.currentIsTail()) {
            return pathToken;
        }

        path.incrementPosition(1);

        if(path.currentChar() != PERIOD && path.currentChar() != OPEN_SQUARE_BRACKET){
            fail("Illegal character at position " + path.position() + " expected '.' or '['");
        }

        PathTokenAppender appender = pathToken.getPathTokenAppender();
        readNextToken(appender);

        return pathToken;
    }

    //
    //
    //
    private boolean readNextToken(PathTokenAppender appender) {

        char c = path.currentChar();

        switch (c) {
            case OPEN_SQUARE_BRACKET:
                if (!readBracketPropertyToken(appender) && !readArrayToken(appender) && !readWildCardToken(appender)
                    && !readFilterToken(appender) && !readPlaceholderToken(appender)) {
                    fail("Could not parse token starting at position " + path.position() + ". Expected ?, ', 0-9, * ");
                }
                return true;
            case PERIOD:
                if (!readDotToken(appender)) {
                    fail("Could not parse token starting at position " + path.position());
                }
                return true;
            case WILDCARD:
                if (!readWildCardToken(appender)) {
                    fail("Could not parse token starting at position " + path.position());
                }
                return true;
            default:
                if (!readPropertyOrFunctionToken(appender)) {
                    fail("Could not parse token starting at position " + path.position());
                }
                return true;
        }
    }

    //
    // . and ..
    //
    private boolean readDotToken(PathTokenAppender appender) {
        if (path.currentCharIs(PERIOD) && path.nextCharIs(PERIOD)) {
            appender.appendPathToken(PathTokenFactory.crateScanToken());
            path.incrementPosition(2);
        } else if (!path.hasMoreCharacters()) {
            throw new InvalidPathException("Path must not end with a '.");
        } else {
            path.incrementPosition(1);
        }
        if(path.currentCharIs(PERIOD)){
            throw new InvalidPathException("Character '.' on position " + path.position() + " is not valid.");
        }
        return readNextToken(appender);
    }

    //
    // fooBar or fooBar()
    //
    private boolean readPropertyOrFunctionToken(PathTokenAppender appender) {
        if (path.currentCharIs(OPEN_SQUARE_BRACKET) || path.currentCharIs(WILDCARD) || path.currentCharIs(PERIOD) || path.currentCharIs(SPACE)) {
            return false;
        }
        int startPosition = path.position();
        int readPosition = startPosition;
        int endPosition = 0;

        boolean isFunction = false;

        while (path.inBounds(readPosition)) {
            char c = path.charAt(readPosition);
            if (c == SPACE) {
                throw new InvalidPathException("Use bracket notion ['my prop'] if your property contains blank characters. position: " + path.position());
            }
            else if (c == PERIOD || c == OPEN_SQUARE_BRACKET) {
                endPosition = readPosition;
                break;
            }
            else if (c == OPEN_PARENTHESIS) {
                isFunction = true;
                endPosition = readPosition;
                break;
            }
            readPosition++;
        }
        if (endPosition == 0) {
            endPosition = path.length();
        }


        List functionParameters = null;
        if (isFunction) {
            int parenthesis_count = 1;
            for(int i = readPosition + 1; i < path.length(); i++){
                if (path.charAt(i) == CLOSE_PARENTHESIS)
                    parenthesis_count--;
                else if (path.charAt(i) == OPEN_PARENTHESIS)
                    parenthesis_count++;
                if (parenthesis_count == 0)
                    break;
            }

            if (parenthesis_count != 0){
                String functionName = path.subSequence(startPosition, endPosition).toString();
                throw new InvalidPathException("Arguments to function: '" + functionName + "' are not closed properly.");
            }

            if (path.inBounds(readPosition+1)) {
                // read the next token to determine if we have a simple no-args function call
                char c = path.charAt(readPosition + 1);
                if (c != CLOSE_PARENTHESIS) {
                    path.setPosition(endPosition+1);
                    // parse the arguments of the function - arguments that are inner queries or JSON document(s)
                    String functionName = path.subSequence(startPosition, endPosition).toString();
                    functionParameters = parseFunctionParameters(functionName);
                } else {
                    path.setPosition(readPosition + 1);
                }
            }
            else {
                path.setPosition(readPosition);
            }
        }
        else {
            path.setPosition(endPosition);
        }

        String property = path.subSequence(startPosition, endPosition).toString();
        if(isFunction){
            appender.appendPathToken(PathTokenFactory.createFunctionPathToken(property, functionParameters));
        } else {
            appender.appendPathToken(PathTokenFactory.createSinglePropertyPathToken(property, SINGLE_QUOTE));
        }

        return path.currentIsTail() || readNextToken(appender);
    }

    /**
     * Parse the parameters of a function call, either the caller has supplied JSON data, or the caller has supplied
     * another path expression which must be evaluated and in turn invoked against the root document.  In this tokenizer
     * we're only concerned with parsing the path thus the output of this function is a list of parameters with the Path
     * set if the parameter is an expression.  If the parameter is a JSON document then the value of the cachedValue is
     * set on the object.
     *
     * Sequence for parsing out the parameters:
     *
     * This code has its own tokenizer - it does some rudimentary level of lexing in that it can distinguish between JSON block parameters
     * and sub-JSON blocks - it effectively regex's out the parameters into string blocks that can then be passed along to the appropriate parser.
     * Since sub-jsonpath expressions can themselves contain other function calls this routine needs to be sensitive to token counting to
     * determine the boundaries.  Since the Path parser isn't aware of JSON processing this uber routine is needed.
     *
     * Parameters are separated by COMMAs ','
     *
     * 
     * doc = {"numbers": [1,2,3,4,5,6,7,8,9,10]}
     *
     * $.sum({10}, $.numbers.avg())
     * 
* * The above is a valid function call, we're first summing 10 + avg of 1...10 (5.5) so the total should be 15.5 * * @return * An ordered list of parameters that are to processed via the function. Typically functions either process * an array of values and/or can consume parameters in addition to the values provided from the consumption of * an array. */ private List parseFunctionParameters(String funcName) { ParamType type = null; // Parenthesis starts at 1 since we're marking the start of a function call, the close paren will denote the // last parameter boundary int groupParen = 1, groupBracket = 0, groupBrace = 0, groupQuote = 0; boolean endOfStream = false; char priorChar = 0; List parameters = new ArrayList(); StringBuilder parameter = new StringBuilder(); while (path.inBounds() && !endOfStream) { char c = path.currentChar(); path.incrementPosition(1); // we're at the start of the stream, and don't know what type of parameter we have if (type == null) { if (isWhitespace(c)) { continue; } if (c == OPEN_BRACE || isDigit(c) || DOUBLE_QUOTE == c) { type = ParamType.JSON; } else if (isPathContext(c)) { type = ParamType.PATH; // read until we reach a terminating comma and we've reset grouping to zero } } switch (c) { case DOUBLE_QUOTE: if (priorChar != '\\' && groupQuote > 0) { groupQuote--; } else { groupQuote++; } break; case OPEN_PARENTHESIS: groupParen++; break; case OPEN_BRACE: groupBrace++; break; case OPEN_SQUARE_BRACKET: groupBracket++; break; case CLOSE_BRACE: if (0 == groupBrace) { throw new InvalidPathException("Unexpected close brace '}' at character position: " + path.position()); } groupBrace--; break; case CLOSE_SQUARE_BRACKET: if (0 == groupBracket) { throw new InvalidPathException("Unexpected close bracket ']' at character position: " + path.position()); } groupBracket--; break; // In either the close paren case where we have zero paren groups left, capture the parameter, or where // we've encountered a COMMA do the same case CLOSE_PARENTHESIS: groupParen--; //CS304 Issue link: https://github.com/json-path/JsonPath/issues/620 if (0 > groupParen || priorChar == '(') { parameter.append(c); } case COMMA: // In this state we've reach the end of a function parameter and we can pass along the parameter string // to the parser if ((0 == groupQuote && 0 == groupBrace && 0 == groupBracket && ((0 == groupParen && CLOSE_PARENTHESIS == c) || 1 == groupParen))) { endOfStream = (0 == groupParen); if (null != type) { Parameter param = null; switch (type) { case JSON: // parse the json and set the value param = new Parameter(parameter.toString()); break; case PATH: LinkedList predicates = new LinkedList<>(); PathCompiler compiler = new PathCompiler(parameter.toString(), predicates); param = new Parameter(compiler.compile()); break; } if (null != param) { parameters.add(param); } parameter.delete(0, parameter.length()); type = null; } } break; } if (type != null && !(c == COMMA && 0 == groupBrace && 0 == groupBracket && 1 == groupParen)) { parameter.append(c); } priorChar = c; } if (0 != groupBrace || 0 != groupParen || 0 != groupBracket) { throw new InvalidPathException("Arguments to function: '" + funcName + "' are not closed properly."); } return parameters; } private boolean isWhitespace(char c) { return (c == SPACE || c == TAB || c == LF || c == CR); } // // [?], [?,?, ..] // private boolean readPlaceholderToken(PathTokenAppender appender) { if (!path.currentCharIs(OPEN_SQUARE_BRACKET)) { return false; } int questionmarkIndex = path.indexOfNextSignificantChar(BEGIN_FILTER); if (questionmarkIndex == -1) { return false; } char nextSignificantChar = path.nextSignificantChar(questionmarkIndex); if (nextSignificantChar != CLOSE_SQUARE_BRACKET && nextSignificantChar != COMMA) { return false; } int expressionBeginIndex = path.position() + 1; int expressionEndIndex = path.nextIndexOf(expressionBeginIndex, CLOSE_SQUARE_BRACKET); if (expressionEndIndex == -1) { return false; } String expression = path.subSequence(expressionBeginIndex, expressionEndIndex).toString(); String[] tokens = expression.split(","); if (filterStack.size() < tokens.length) { throw new InvalidPathException("Not enough predicates supplied for filter [" + expression + "] at position " + path.position()); } Collection predicates = new ArrayList(); for (String token : tokens) { token = token != null ? token.trim() : null; if (!"?".equals(token == null ? "" : token)) { throw new InvalidPathException("Expected '?' but found " + token); } predicates.add(filterStack.pop()); } appender.appendPathToken(PathTokenFactory.createPredicatePathToken(predicates)); path.setPosition(expressionEndIndex + 1); return path.currentIsTail() || readNextToken(appender); } // // [?(...)] // private boolean readFilterToken(PathTokenAppender appender) { if (!path.currentCharIs(OPEN_SQUARE_BRACKET) && !path.nextSignificantCharIs(BEGIN_FILTER)) { return false; } int openStatementBracketIndex = path.position(); int questionMarkIndex = path.indexOfNextSignificantChar(BEGIN_FILTER); if (questionMarkIndex == -1) { return false; } int openBracketIndex = path.indexOfNextSignificantChar(questionMarkIndex, OPEN_PARENTHESIS); if (openBracketIndex == -1) { return false; } int closeBracketIndex = path.indexOfClosingBracket(openBracketIndex, true, true); if (closeBracketIndex == -1) { return false; } if (!path.nextSignificantCharIs(closeBracketIndex, CLOSE_SQUARE_BRACKET)) { return false; } int closeStatementBracketIndex = path.indexOfNextSignificantChar(closeBracketIndex, CLOSE_SQUARE_BRACKET); String criteria = path.subSequence(openStatementBracketIndex, closeStatementBracketIndex + 1).toString(); Predicate predicate = FilterCompiler.compile(criteria); appender.appendPathToken(PathTokenFactory.createPredicatePathToken(predicate)); path.setPosition(closeStatementBracketIndex + 1); return path.currentIsTail() || readNextToken(appender); } // // [*] // * // private boolean readWildCardToken(PathTokenAppender appender) { boolean inBracket = path.currentCharIs(OPEN_SQUARE_BRACKET); if (inBracket && !path.nextSignificantCharIs(WILDCARD)) { return false; } if (!path.currentCharIs(WILDCARD) && path.isOutOfBounds(path.position() + 1)) { return false; } if (inBracket) { int wildCardIndex = path.indexOfNextSignificantChar(WILDCARD); if (!path.nextSignificantCharIs(wildCardIndex, CLOSE_SQUARE_BRACKET)) { int offset = wildCardIndex + 1; throw new InvalidPathException("Expected wildcard token to end with ']' on position " + offset); } int bracketCloseIndex = path.indexOfNextSignificantChar(wildCardIndex, CLOSE_SQUARE_BRACKET); path.setPosition(bracketCloseIndex + 1); } else { path.incrementPosition(1); } appender.appendPathToken(PathTokenFactory.createWildCardPathToken()); return path.currentIsTail() || readNextToken(appender); } // // [1], [1,2, n], [1:], [1:2], [:2] // private boolean readArrayToken(PathTokenAppender appender) { if (!path.currentCharIs(OPEN_SQUARE_BRACKET)) { return false; } char nextSignificantChar = path.nextSignificantChar(); if (!isDigit(nextSignificantChar) && nextSignificantChar != MINUS && nextSignificantChar != SPLIT) { return false; } int expressionBeginIndex = path.position() + 1; int expressionEndIndex = path.nextIndexOf(expressionBeginIndex, CLOSE_SQUARE_BRACKET); if (expressionEndIndex == -1) { return false; } String expression = path.subSequence(expressionBeginIndex, expressionEndIndex).toString().trim(); if ("*".equals(expression)) { return false; } //check valid chars for (int i = 0; i < expression.length(); i++) { char c = expression.charAt(i); if (!isDigit(c) && c != COMMA && c != MINUS && c != SPLIT && c != SPACE) { return false; } } boolean isSliceOperation = expression.contains(":"); if (isSliceOperation) { ArraySliceOperation arraySliceOperation = ArraySliceOperation.parse(expression); appender.appendPathToken(PathTokenFactory.createSliceArrayPathToken(arraySliceOperation)); } else { ArrayIndexOperation arrayIndexOperation = ArrayIndexOperation.parse(expression); appender.appendPathToken(PathTokenFactory.createIndexArrayPathToken(arrayIndexOperation)); } path.setPosition(expressionEndIndex + 1); return path.currentIsTail() || readNextToken(appender); } // // ['foo'] // private boolean readBracketPropertyToken(PathTokenAppender appender) { if (!path.currentCharIs(OPEN_SQUARE_BRACKET)) { return false; } char potentialStringDelimiter = path.nextSignificantChar(); if (potentialStringDelimiter != SINGLE_QUOTE && potentialStringDelimiter != DOUBLE_QUOTE) { return false; } List properties = new ArrayList(); int startPosition = path.position() + 1; int readPosition = startPosition; int endPosition = 0; boolean inProperty = false; boolean inEscape = false; boolean lastSignificantWasComma = false; while (path.inBounds(readPosition)) { char c = path.charAt(readPosition); if(inEscape){ inEscape = false; } else if('\\' == c){ inEscape = true; } else if (c == CLOSE_SQUARE_BRACKET && !inProperty) { if (lastSignificantWasComma){ fail("Found empty property at index "+readPosition); } break; } else if (c == potentialStringDelimiter) { if (inProperty) { char nextSignificantChar = path.nextSignificantChar(readPosition); if (nextSignificantChar != CLOSE_SQUARE_BRACKET && nextSignificantChar != COMMA) { fail("Property must be separated by comma or Property must be terminated close square bracket at index "+readPosition); } endPosition = readPosition; String prop = path.subSequence(startPosition, endPosition).toString(); properties.add(Utils.unescape(prop)); inProperty = false; } else { startPosition = readPosition + 1; inProperty = true; lastSignificantWasComma = false; } } else if (c == COMMA && !inProperty) { if (lastSignificantWasComma){ fail("Found empty property at index "+readPosition); } lastSignificantWasComma = true; } readPosition++; } if (inProperty){ fail("Property has not been closed - missing closing " + potentialStringDelimiter); } int endBracketIndex = path.indexOfNextSignificantChar(endPosition, CLOSE_SQUARE_BRACKET) + 1; path.setPosition(endBracketIndex); appender.appendPathToken(PathTokenFactory.createPropertyPathToken(properties, potentialStringDelimiter)); return path.currentIsTail() || readNextToken(appender); } public static boolean fail(String message) { throw new InvalidPathException(message); } }




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