程序包 cn.taketoday.expression.common

类 TemplateAwareExpressionParser

java.lang.Object

cn.taketoday.expression.common.TemplateAwareExpressionParser

所有已实现的接口:

ExpressionParser

直接已知子类:

InternalSpelExpressionParser, SpelExpressionParser

public abstract class TemplateAwareExpressionParser
extends Object
implements ExpressionParser

An expression parser that understands templates. It can be subclassed by expression parsers that do not offer first class support for templating.

从以下版本开始:

4.0

作者:

Keith Donald, Juergen Hoeller, Andy Clement

嵌套类概要

嵌套类

修饰符和类型	类	说明
private static class	TemplateAwareExpressionParser.Bracket	This captures a type of bracket and the position in which it occurs in the expression.

构造器概要

构造器

构造器	说明
TemplateAwareExpressionParser()

方法概要

修饰符和类型	方法	说明
protected abstract Expression	doParseExpression(String expressionString, ParserContext context)	Actually parse the expression string and return an Expression object.
private boolean	isSuffixHere(String expressionString, int pos, String suffix)	Return true if the specified suffix can be found at the supplied position in the supplied expression string.
Expression	parseExpression(String expressionString)	Parse the expression string and return an Expression object you can use for repeated evaluation.
Expression	parseExpression(String expressionString, ParserContext context)	Parse the expression string and return an Expression object you can use for repeated evaluation.
private List<Expression>	parseExpressions(String expressionString, ParserContext context)	Helper that parses given expression string using the configured parser.
private Expression	parseTemplate(String expressionString, ParserContext context)
private int	skipToCorrectEndSuffix(String suffix, String expressionString, int afterPrefixIndex)	Copes with nesting, for example '${...${...}}' where the correct end for the first ${ is the final }.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

TemplateAwareExpressionParser

public TemplateAwareExpressionParser()

方法详细资料

parseExpression

public Expression parseExpression(String expressionString)
                           throws ParseException

从接口复制的说明: ExpressionParser

Parse the expression string and return an Expression object you can use for repeated evaluation.

Some examples:

     3 + 4
     name.firstName
 

指定者:

parseExpression 在接口中 ExpressionParser

参数:

expressionString - the raw expression string to parse

返回:

an evaluator for the parsed expression

抛出:

ParseException - an exception occurred during parsing

parseExpression

public Expression parseExpression(String expressionString,
 @Nullable
 ParserContext context)
                           throws ParseException

从接口复制的说明: ExpressionParser

Parse the expression string and return an Expression object you can use for repeated evaluation.

Some examples:

     3 + 4
     name.firstName
 

指定者:

parseExpression 在接口中 ExpressionParser

参数:

expressionString - the raw expression string to parse

context - a context for influencing this expression parsing routine (optional)

返回:

an evaluator for the parsed expression

抛出:

ParseException - an exception occurred during parsing

parseTemplate

private Expression parseTemplate(String expressionString,
 ParserContext context)
                          throws ParseException

抛出:

ParseException

parseExpressions

private List<Expression> parseExpressions(String expressionString,
 ParserContext context)
                                   throws ParseException

Helper that parses given expression string using the configured parser. The expression string can contain any number of expressions all contained in "${...}" markers. For instance: "foo${expr0}bar${expr1}". The static pieces of text will also be returned as Expressions that just return that static piece of text. As a result, evaluating all returned expressions and concatenating the results produces the complete evaluated string. Unwrapping is only done of the outermost delimiters found, so the string 'hello ${foo${abc}}' would break into the pieces 'hello ' and 'foo${abc}'. This means that expression languages that used ${..} as part of their functionality are supported without any problem. The parsing is aware of the structure of an embedded expression. It assumes that parentheses '(', square brackets '[' and curly brackets '}' must be in pairs within the expression unless they are within a string literal and a string literal starts and terminates with a single quote '.

参数:

expressionString - the expression string

返回:

the parsed expressions

抛出:

ParseException - when the expressions cannot be parsed

isSuffixHere

private boolean isSuffixHere(String expressionString,
 int pos,
 String suffix)

Return true if the specified suffix can be found at the supplied position in the supplied expression string.

参数:

expressionString - the expression string which may contain the suffix

pos - the start position at which to check for the suffix

suffix - the suffix string

skipToCorrectEndSuffix

private int skipToCorrectEndSuffix(String suffix,
 String expressionString,
 int afterPrefixIndex)
                            throws ParseException

Copes with nesting, for example '${...${...}}' where the correct end for the first ${ is the final }.

参数:

suffix - the suffix

expressionString - the expression string

afterPrefixIndex - the most recently found prefix location for which the matching end suffix is being sought

返回:

the position of the correct matching nextSuffix or -1 if none can be found

抛出:

ParseException

doParseExpression

protected abstract Expression doParseExpression(String expressionString,
 @Nullable
 ParserContext context)
                                         throws ParseException

Actually parse the expression string and return an Expression object.

参数:

expressionString - the raw expression string to parse

context - a context for influencing this expression parsing routine (optional)

返回:

an evaluator for the parsed expression

抛出:

ParseException - an exception occurred during parsing