FilterReaderUnwrapper.java 文件源码

public Reader unwrap(FilterReader originalReader) throws IllegalArgumentException {
    try {
        return (Reader) internalField.get(originalReader);
    } catch (Exception ex) {
        throw new IllegalArgumentException("Could not access private \"in\" field of the given FilterReader (actual class: " + originalReader.getClass().getCanonicalName() + ")", ex);
    }
}