CMPUT 301

Class Participation Exercise: Proxy Pattern

Use the Proxy pattern to improve performance by not reading files that aren't actually needed yet.

interface OurFile {
    byte[] fileContents(); // returns entire file
    String getName();
}
class ConcreteFile implements OurFile {
    String name;
    byte[] fileContents;
    ConcreteFile(String name) { ... }
    String getName() { return name; }
    byte[] fileContents() { return fileContents; }
    ...
}

assume ConcreteFile exists and implements OurFile. ConcreteFile reads the entire file when it is constructed.

Write java code for ProxyFile that proxies a ConcreteFile and doesn't have to read the entire file until the contents of the file are needed, using the proxy pattern.