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refactor PropertyPlaceholderHelper
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Signed-off-by: Dmitrii Bocharov <[email protected]>
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@bdshadow
bdshadow committed Nov 1, 2023
1 parent 605bc3c commit 97a324d
Showing 1 changed file with 116 additions and 95 deletions.
211 changes: 116 additions & 95 deletions spring-core/src/main/java/org/springframework/util/PropertyPlaceholderHelper.java
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Original file line number Diff line number Diff line change
Expand Up @@ -148,125 +148,146 @@ public String replacePlaceholders(String value, PlaceholderResolver placeholderR

protected String parseStringValue(
String value, PlaceholderResolver placeholderResolver, @Nullable Set<String> visitedPlaceholders) {
String resolvedPlaceholders = resolvePlaceholders(value, placeholderResolver, visitedPlaceholders);
return removeEscapeCharacters(resolvedPlaceholders);
Property property = new Property(value, placeholderResolver);
property.resolvePlaceholders(visitedPlaceholders);
return property.removeEscapeCharacters();
}

private String removeEscapeCharacters(String resolvePlaceholders) {
StringBuilder result = new StringBuilder(resolvePlaceholders);
String escapedPrefix = this.escapeCharacter + this.placeholderPrefix;
int startIndex = result.indexOf(escapedPrefix);
while (startIndex != -1) {
int endIndex = findPlaceholderEndIndex(result, startIndex + 1);
if (endIndex != -1) {
result.replace(startIndex, startIndex + escapedPrefix.length(), this.placeholderPrefix);
startIndex = result.indexOf(escapedPrefix, endIndex + this.placeholderSuffix.length());
}
else {
break;
}
}
return result.toString();
}
protected class Property {

protected String resolvePlaceholders(
String value, PlaceholderResolver placeholderResolver, @Nullable Set<String> visitedPlaceholders) {
protected final String escapedPrefix = escapeCharacter + placeholderPrefix;

StringBuilder result = new StringBuilder(value);
int startIndex = findPlaceholderPrefixIndex(result, 0);
protected final String originalPlaceholder;
protected final StringBuilder result;
protected final PlaceholderResolver placeholderResolver;

while (startIndex != -1) {
int endIndex = findPlaceholderEndIndex(result, startIndex);
if (endIndex != -1) {
String placeholder = result.substring(startIndex + this.placeholderPrefix.length(), endIndex);
String originalPlaceholder = placeholder;
if (visitedPlaceholders == null) {
visitedPlaceholders = new HashSet<>(4);
}
if (!visitedPlaceholders.add(originalPlaceholder)) {
throw new IllegalArgumentException(
"Circular placeholder reference '" + originalPlaceholder + "' in property definitions");
}
// Recursive invocation, parsing placeholders contained in the placeholder key.
placeholder = resolvePlaceholders(placeholder, placeholderResolver, visitedPlaceholders);
// Now obtain the value for the fully resolved key...
String propVal = placeholderResolver.resolvePlaceholder(placeholder);
if (propVal == null && this.valueSeparator != null) {
int separatorIndex = placeholder.indexOf(this.valueSeparator);
if (separatorIndex != -1) {
String actualPlaceholder = placeholder.substring(0, separatorIndex);
String defaultValue = placeholder.substring(separatorIndex + this.valueSeparator.length());
propVal = placeholderResolver.resolvePlaceholder(actualPlaceholder);
if (propVal == null) {
propVal = defaultValue;
protected Property(String value, PlaceholderResolver placeholderResolver) {
this.originalPlaceholder = value;
this.result = new StringBuilder(value);
this.placeholderResolver = placeholderResolver;
}

protected String resolvePlaceholders(Set<String> visitedPlaceholders) {
int startIndex = findPlaceholderPrefixIndex(0);

while (startIndex != -1) {
int endIndex = findPlaceholderEndIndex(startIndex);
if (endIndex != -1) {
String placeholderWithoutBrackets = this.result.substring(startIndex + placeholderPrefix.length(), endIndex);
visitedPlaceholders = updateVisitedPlaceholders(visitedPlaceholders, placeholderWithoutBrackets);

Property property = new Property(placeholderWithoutBrackets, this.placeholderResolver);
property.resolvePlaceholders(visitedPlaceholders);
String placeholderValue = property.getValue();

if (placeholderValue != null) {
Property valueProperty = new Property(placeholderValue, this.placeholderResolver);
placeholderValue = valueProperty.resolvePlaceholders(visitedPlaceholders);
this.result.replace(startIndex, endIndex + placeholderSuffix.length(), placeholderValue);
if (logger.isTraceEnabled()) {
logger.trace("Resolved placeholder '" + property.result + "'");
}
startIndex = this.result.indexOf(placeholderPrefix, startIndex + placeholderValue.length());

}
}
if (propVal != null) {
// Recursive invocation, parsing placeholders contained in the
// previously resolved placeholder value.
propVal = resolvePlaceholders(propVal, placeholderResolver, visitedPlaceholders);
result.replace(startIndex, endIndex + this.placeholderSuffix.length(), propVal);
if (logger.isTraceEnabled()) {
logger.trace("Resolved placeholder '" + placeholder + "'");
else if (ignoreUnresolvablePlaceholders) {
// Proceed with unprocessed value.
startIndex = this.result.indexOf(placeholderPrefix, endIndex + placeholderSuffix.length());
}
startIndex = result.indexOf(this.placeholderPrefix, startIndex + propVal.length());
}
else if (this.ignoreUnresolvablePlaceholders) {
// Proceed with unprocessed value.
startIndex = result.indexOf(this.placeholderPrefix, endIndex + this.placeholderSuffix.length());
else {
throw new IllegalArgumentException("Could not resolve placeholder '" +
property.result + "'" + " in value \"" + this.originalPlaceholder + "\"");
}
visitedPlaceholders.remove(placeholderWithoutBrackets);
}
else {
throw new IllegalArgumentException("Could not resolve placeholder '" +
placeholder + "'" + " in value \"" + value + "\"");
startIndex = -1;
}
visitedPlaceholders.remove(originalPlaceholder);
}
else {
startIndex = -1;
return this.result.toString();
}

protected Set<String> updateVisitedPlaceholders(Set<String> visitedPlaceholders, String placeholderWithoutBrackets) {
if (visitedPlaceholders == null) {
visitedPlaceholders = new HashSet<>(4);
}
if (!visitedPlaceholders.add(placeholderWithoutBrackets)) {
throw new IllegalArgumentException(
"Circular placeholder reference '" + placeholderWithoutBrackets + "' in property definitions");
}
return visitedPlaceholders;
}
return result.toString();
}

private int findPlaceholderEndIndex(CharSequence buf, int startIndex) {
int index = startIndex + this.placeholderPrefix.length();
int withinNestedPlaceholder = 0;
while (index < buf.length()) {
if (StringUtils.substringMatch(buf, index, this.placeholderSuffix)) {
if (withinNestedPlaceholder > 0) {
withinNestedPlaceholder--;
index = index + this.placeholderSuffix.length();
protected int findPlaceholderPrefixIndex(int startIndex) {
int prefixIndex = this.result.indexOf(placeholderPrefix, startIndex);
//check if prefix is not escaped
if (prefixIndex < 1) {
return prefixIndex;
}
if (this.result.charAt(prefixIndex - 1) == escapeCharacter) {
int endOfEscaped = findPlaceholderEndIndex(prefixIndex);
if (endOfEscaped == -1) {
return -1;
}
return findPlaceholderPrefixIndex(endOfEscaped + 1);
}
return prefixIndex;
}

protected int findPlaceholderEndIndex(int startIndex) {
int index = startIndex + placeholderPrefix.length();
int withinNestedPlaceholder = 0;
while (index < this.result.length()) {
if (StringUtils.substringMatch(this.result, index, placeholderSuffix)) {
if (withinNestedPlaceholder > 0) {
withinNestedPlaceholder--;
index = index + placeholderSuffix.length();
}
else {
return index;
}
}
else if (StringUtils.substringMatch(this.result, index, simplePrefix)) {
withinNestedPlaceholder++;
index = index + simplePrefix.length();
}
else {
return index;
index++;
}
}
else if (StringUtils.substringMatch(buf, index, this.simplePrefix)) {
withinNestedPlaceholder++;
index = index + this.simplePrefix.length();
}
else {
index++;
}
return -1;
}
return -1;
}

private int findPlaceholderPrefixIndex(StringBuilder value, int startIndex) {
int prefixIndex = value.indexOf(this.placeholderPrefix, startIndex);
//check if prefix is not escaped
if (prefixIndex < 1) {
return prefixIndex;
protected String getValue() {
String propVal = this.placeholderResolver.resolvePlaceholder(this.result.toString());
if (propVal == null && valueSeparator != null) {
int separatorIndex = this.result.indexOf(valueSeparator);
if (separatorIndex != -1) {
String actualPlaceholder = this.result.substring(0, separatorIndex);
String defaultValue = this.result.substring(separatorIndex + valueSeparator.length());
propVal = this.placeholderResolver.resolvePlaceholder(actualPlaceholder);
if (propVal == null) {
propVal = defaultValue;
}
}
}
return propVal;
}
if (value.charAt(prefixIndex - 1) == this.escapeCharacter) {
int endOfEscaped = findPlaceholderEndIndex(value, prefixIndex);
if (endOfEscaped == -1) {
return -1;

protected String removeEscapeCharacters() {
int startIndex = this.result.indexOf(this.escapedPrefix);
while (startIndex != -1) {
int endIndex = findPlaceholderEndIndex(startIndex + 1);
if (endIndex != -1) {
this.result.replace(startIndex, startIndex + this.escapedPrefix.length(), placeholderPrefix);
startIndex = this.result.indexOf(this.escapedPrefix, endIndex + placeholderSuffix.length());
}
else {
break;
}
}
return findPlaceholderPrefixIndex(value, endOfEscaped + 1);
return this.result.toString();
}
return prefixIndex;
}

/**
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