InspectorImpl.java

package org.limewire.inspection;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.Singleton;

@Singleton
public class InspectorImpl implements Inspector {

    private static Log LOG = LogFactory.getLog(InspectorImpl.class);
    
    private volatile Properties props;
    private volatile Injector injector;

    private final AtomicBoolean loading = new AtomicBoolean(false);
    
    @Inject
    InspectorImpl(Injector injector) {
        this.injector = injector;
    }
    
    @Override
    public void setInjector(Injector injector) {
        this.injector = injector;
    }
    
    public Object inspect(String key, boolean collectUsageData) throws InspectionException {
        String target;
        if (props == null || !props.containsKey(key))
            target = key; // assume they know what they're doing
        else
            target = props.getProperty(key);
        return InspectionUtils.inspectValue(target, injector, collectUsageData);
    }
    
    public boolean loaded() {
        return props != null && !props.isEmpty();
    }

    public void load(File props) {
        if (loading.getAndSet(true))
            return;
        
        /*
         * Ignore any and all errors as inspection is not critical functionality
         */
        BufferedReader in = null;
        Properties p = new Properties();
        try {
            // we're allowing inspection keys to be utf-8
            in = new BufferedReader(new InputStreamReader(new FileInputStream(props), Charset.forName("UTF-8")));
            String current = null;
            while((current = in.readLine()) != null) {
                String [] k = current.split("=");
                if (k.length != 2)
                    continue;
                p.setProperty(k[0], k[1]);
            }
            this.props = p;
        } catch(IllegalArgumentException ignored) {
            LOG.trace("illegal argument", ignored);
        } catch(StringIndexOutOfBoundsException sioobe) {
            LOG.trace("index out of bounds", sioobe);
        } catch(IOException iox) {
            LOG.trace("IO", iox);
        }
        finally {
            if (in != null)
                try {in.close();} catch (IOException ignore){}
        }
    }

}