Question

I’m trying to make a Java program more “Groovy”. The java code reads an InputStream like so:

static int myFunction(InputStream is) throws IOException {
    int b=is.read();
    if (b==0) return b;
    StringBuffer sb=new StringBuffer();
    int c;
    boolean done = false;
    while(!done) {
        c=is.read();
        sb.append((char)c);
        if(c == '\n') {
           done=true;
        }
    }
    System.out.println(sb.toString());
    if (b == 1) throw new IOException("blah");
    return b;
}

My Groovy version looks like this:

def myFunction(InputStream is) throws IOException {
    int b=is.read()
    if (b==0) return b
    def reader = new BufferedReader(new InputStreamReader(is))
    reader.eachLine { println(it) } 
    println("DONE")
    if (b == 1) throw new IOException("blah")
    return b
}

It prints the contents of the stream and then just hangs as if it’s trying to read more. It never prints “DONE” (added for debugging). Next I tried it using is.eachByte and passing a closure with an explicit “if (c == ‘\n’) return” but I found that return inside a closure acts more like a continue and doesn’t actually break out of the closure. Any idea what I’m doing wrong?

Answer 1

Instead of

reader.eachLine { println(it) } 

Can you try

println reader.readLine()