[Demonstration 1]

[Buggy Method]
public String networkCom(String urlType, String urlParameters, String type) {
    URL url;
    HttpURLConnection connection = null;
    try {
        url = new URL("http://localhost:8080/" + urlType);
        connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod(type);
        connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        connection.setRequestProperty("Content-Length", "" + Integer.toString(urlParameters.getBytes().length));
        connection.setRequestProperty("Content-Language", "en-US");
        connection.setUseCaches(false);
        connection.setDoInput(true);
        connection.setDoOutput(true);
        //Send request
        DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
        wr.writeBytes(urlParameters);
        wr.flush();
        wr.close();
        //Get Response
        InputStream is = connection.getInputStream();
        BufferedReader rd = new BufferedReader(new InputStreamReader(is));
        String line;
        StringBuffer response = new StringBuffer();
        while ((line = rd.readLine()) != null) {
            response.append(line);
            response.append('\r');
        }
        rd.close();
        return response.toString();
    } catch (Exception ex) {
        ex.printStackTrace();
    } finally {
        if (connection != null) {
            connection.disconnect();
        }
    }
    return null;
}

[Buggy Hunk]
public String networkCom(String urlType, String urlParameters, String type) {

[Patch]
private final String networkCom(String urlType, String urlParameters, String type) {

[Demonstration 2]

[Buggy Method]
public void close() throws IOException {
    if (connection != null)
        connection.close();
}

[Buggy Hunk]
if(connection != null) connection.close();

[Patch]
if( (connection != null) && (!connection.isClosed())) connection.close();

[Demonstration 3]

[Buggy Method]
private Map<?, ?> mapView(Object obj, Class<?> sourceCls, InternalConverter converter) {
    if (Map.class.isAssignableFrom(sourceCls))
        return (Map<?, ?>) obj;
    else if (Dictionary.class.isAssignableFrom(sourceCls))
        // TODO
        return null;
    else if (isDTOType(sourceCls) || DTO.class.equals(sourceCls))
        return createMapFromDTO(obj, converter);
    else {
        if (sourceAsJavaBean) {
            Map<?, ?> m = createMapFromBeanAccessors(obj, sourceCls);
            if (m.size() > 0)
                return m;
        }
    }
    return createMapFromInterface(obj);
}

[Buggy Hunk]
if (Map.class.isAssignableFrom(sourceCls))

[Patch]
if (Map.class.isAssignableFrom(sourceCls) || (DTO.class.equals(sourceCls) && obj instanceof Map))