Spring AbstractPropertyResolver

/**
 * 配置过的 转换服务
 */
@Nullable
private volatile ConfigurableConversionService conversionService;

/**
 * 占位符解析工具
 */
@Nullable
private PropertyPlaceholderHelper nonStrictHelper;

/**
 * 占位符解析工具
 */
@Nullable
private PropertyPlaceholderHelper strictHelper;

/**
 * 遇到无法解析的占位符是否需要抛出异常
 */
private boolean ignoreUnresolvableNestedPlaceholders = false;

/**
 * 前缀
 */
private String placeholderPrefix = SystemPropertyUtils.PLACEHOLDER_PREFIX;

/**
 * 后缀
 */
private String placeholderSuffix = SystemPropertyUtils.PLACEHOLDER_SUFFIX;

/**
 * 值分割符号
 */
@Nullable
private String valueSeparator = SystemPropertyUtils.VALUE_SEPARATOR;

@Override
public void setPlaceholderPrefix(String placeholderPrefix) {
   Assert.notNull(placeholderPrefix, "'placeholderPrefix' must not be null");
   this.placeholderPrefix = placeholderPrefix;
}

@Override
@Nullable
public String getProperty(String key) {
   return getProperty(key, String.class);
}