import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver; //导入依赖的package包/类
/**
 * Replaces each occurence of ${SOME_VALUE} with the varible SOME_VALUE in 'variables'
 * If any error occures during parsing, i.e: variable doesn't exist, bad syntax, etc...
 * a {@link PlaceholderResolutionException} is thrown, otherwise the new string after all replacements have been
 * made will be returned.
 * 
 * @param variables The variables map to match placeholders against
 * @param value the string, possibly containing placeholders
 * @return the value after placeholder replacement have been made
 * @throws PlaceholderResolutionException if an empty placeholder is found 
 *      or a place holder with no suitable value in 'variables'
 */
public static String replacePlaceholders(final Map<String, String> variables, final String value) throws PlaceholderResolutionException {
    PropertyPlaceholderHelper helper = new PropertyPlaceholderHelper("${","}");
    return helper.replacePlaceholders(value, new PlaceholderResolver() {
        public String resolvePlaceholder(String key) {
            if (key.isEmpty()) {
                throw new PlaceholderResolutionException("Placeholder in '" + value + "' has to have a length of at least 1");
            }
            
            String result = variables.get(key);
            if (result == null) {
                throw new PlaceholderResolutionException("Missing value for placeholder: '" + key + "' in '" + value + "'");
            }
            
            return result;
        }
    });
}
 

import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver; //导入依赖的package包/类
public StaticStringValueResolver(final Map<String, String> values) {
	this.helper = new PropertyPlaceholderHelper("${", "}", ":", false);
	this.resolver = new PlaceholderResolver() {
		@Override
		public String resolvePlaceholder(String placeholderName) {
			return values.get(placeholderName);
		}
	};
}
 

import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver; //导入依赖的package包/类
@Override
public void render(Map<String, ?> model, HttpServletRequest request,
		HttpServletResponse response) throws Exception {
	if (response.getContentType() == null) {
		response.setContentType(getContentType());
	}
	Map<String, Object> map = new HashMap<String, Object>(model);
	map.put("path", request.getContextPath());
	PlaceholderResolver resolver = new ExpressionResolver(getExpressions(), map);
	String result = this.helper.replacePlaceholders(this.template, resolver);
	response.getWriter().append(result);
}
 

import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver; //导入依赖的package包/类
@Override
public void render(Map<String, ?> model, HttpServletRequest request,
		HttpServletResponse response) throws Exception {
	if (response.getContentType() == null) {
		response.setContentType(getContentType());
	}
	Map<String, Object> map = new HashMap<String, Object>(model);
	map.put("path", request.getContextPath());
	PlaceholderResolver resolver = new ExpressionResolver(this.expressions, map);
	String result = this.helper.replacePlaceholders(this.template, resolver);
	response.getWriter().append(result);
}
 

import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver; //导入依赖的package包/类
public SpelView(String template) {
	this.template = template;
	this.context.addPropertyAccessor(new MapAccessor());
	this.helper = new PropertyPlaceholderHelper("${", "}");
	this.resolver = new PlaceholderResolver() {
		public String resolvePlaceholder(String name) {
			Expression expression = parser.parseExpression(name);
			Object value = expression.getValue(context);
			return value==null ? null : value.toString();
		}
	};
}
 

import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver; //导入依赖的package包/类
/**
 * replace placeholder in properties file with value;
 * @param placeholders placeholder to replace
 */
public final void replacePlaceholders(Map<String, String> placeholders) {
    PropertyPlaceholderHelper helper = new PropertyPlaceholderHelper(placeholderPrefix, placeholderSuffix, valueSeparator,
            ignoreUnresolvablePlaceholders);
    PlaceholderResolver resolver = new PlaceholderConfigurerResolver(placeholders);
    for (Object key : this.properties.keySet()) {
        Object val = this.properties.get(key);
        this.properties.setProperty(key.toString(), helper.replacePlaceholders(val.toString(), resolver));
    }

}
 

import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver; //导入依赖的package包/类
@SuppressWarnings("unchecked")
private PlaceholderResolver initVarResolver(MessageHeaders headers) {
	String name = DestinationVariableMethodArgumentResolver.DESTINATION_TEMPLATE_VARIABLES_HEADER;
	Map<String, String> vars = (Map<String, String>) headers.get(name);
	return new DestinationVariablePlaceholderResolver(vars);
}
 

import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver; //导入依赖的package包/类
/**
 * Parse the given String value for placeholder resolution.
 * @param strVal the String value to parse
 * @param props the Properties to resolve placeholders against
 * @param visitedPlaceholders the placeholders that have already been visited
 * during the current resolution attempt (ignored in this version of the code)
 * @deprecated as of Spring 3.0, in favor of using {@link #resolvePlaceholder}
 * with {@link org.springframework.util.PropertyPlaceholderHelper}.
 * Only retained for compatibility with Spring 2.5 extensions.
 */
@Deprecated
protected String parseStringValue(String strVal, Properties props, Set<?> visitedPlaceholders) {
	PropertyPlaceholderHelper helper = new PropertyPlaceholderHelper(
			placeholderPrefix, placeholderSuffix, valueSeparator, ignoreUnresolvablePlaceholders);
	PlaceholderResolver resolver = new PropertyPlaceholderConfigurerResolver(props);
	return helper.replacePlaceholders(strVal, resolver);
}