#vulnerable code 
                             @Override
	public HttpResponse execute(HttpRequest request) throws HttpClientException {
		HttpResponse response = null;
		try {
			URI uri = new URI(request.getURI().toString(), false,
					Consts.UTF_8.name());
			org.apache.commons.httpclient.HttpMethod httpMethod = methodMap
					.get(request.getMethod());
			if (request.getMethod() == HttpMethod.TRACE) {
				httpMethod = new TraceMethod(uri.getEscapedURI());
			} else {
				httpMethod.setURI(uri);
			}
			HttpParams params = request.getParams();
			if (params != null) {
				Proxy proxy = params.getProxy();
				if (proxy != null) {
					InetSocketAddress socketAddress = (InetSocketAddress) proxy
							.address();
					httpClient.getHostConfiguration().setProxy(
							socketAddress.getHostName(),
							socketAddress.getPort());
				}
				SSLContext sslContext = params.getSSLContext();
				if (sslContext != null) {
					Protocol.registerProtocol("https", new Protocol("https",
							new SSLProtocolSocketFactory(sslContext), 443));
				}
				httpClient.getHttpConnectionManager().getParams()
						.setConnectionTimeout(params.getConnectTimeout());
				httpClient.getHttpConnectionManager().getParams()
						.setSendBufferSize(params.getChunkSize());
				httpMethod.getParams().setUriCharset(Consts.UTF_8.name());
				httpMethod.getParams().setSoTimeout(params.getSocketTimeout());
				httpMethod.getParams().setContentCharset(Consts.UTF_8.name());
			}
			com.foxinmy.weixin4j.http.HttpHeaders headers = request
					.getHeaders();
			if (headers == null) {
				headers = new HttpHeaders();
			}
			if (!headers.containsKey(HttpHeaders.HOST)) {
				headers.set(HttpHeaders.HOST, uri.getHost());
			}
			// Add default accept headers
			if (!headers.containsKey(HttpHeaders.ACCEPT)) {
				headers.set(HttpHeaders.ACCEPT, "*/*");
			}
			// Add default user agent
			if (!headers.containsKey(HttpHeaders.USER_AGENT)) {
				headers.set(HttpHeaders.USER_AGENT, "apache/httpclient3");
			}
			for (Iterator<Entry<String, List<String>>> headerIterator = headers
					.entrySet().iterator(); headerIterator.hasNext();) {
				Entry<String, List<String>> header = headerIterator.next();
				if (HttpHeaders.COOKIE.equalsIgnoreCase(header.getKey())) {
					httpMethod.setRequestHeader(header.getKey(),
							StringUtil.join(header.getValue(), ';'));
				} else {
					for (String headerValue : header.getValue()) {
						httpMethod.addRequestHeader(header.getKey(),
								headerValue != null ? headerValue : "");
					}
				}
			}
			HttpEntity entity = request.getEntity();
			if (entity != null) {
				if (entity.getContentLength() > 0l) {
					httpMethod.addRequestHeader(HttpHeaders.CONTENT_LENGTH,
							Long.toString(entity.getContentLength()));
				}
				if (entity.getContentType() != null) {
					httpMethod.addRequestHeader(HttpHeaders.CONTENT_TYPE,
							entity.getContentType().toString());
				}
				RequestEntity requestEntity = null;
				if (entity instanceof MultipartEntity) {
					ByteArrayOutputStream os = new ByteArrayOutputStream();
					entity.writeTo(os);
					os.flush();
					requestEntity = new ByteArrayRequestEntity(
							os.toByteArray(), entity.getContentType()
									.toString());
					os.close();
				} else {
					requestEntity = new InputStreamRequestEntity(
							entity.getContent(), entity.getContentType()
									.toString());
				}
				((EntityEnclosingMethod) httpMethod)
						.setRequestEntity(requestEntity);
			}
			httpClient.executeMethod(httpMethod);
			response = new HttpComponent3Response(httpMethod);
			handleResponse(response);
		} catch (IOException e) {
			throw new HttpClientException("I/O error on "
					+ request.getMethod().name() + " request for \""
					+ request.getURI().toString() + "\":" + e.getMessage(), e);
		} finally {
			if (response != null) {
				response.close();
			}
		}
		return response;
	} 
                            #location 83 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             @Override
	public HttpResponse execute(HttpRequest request) throws HttpClientException {
		HttpResponse response = null;
		try {
			URI uri = new URI(request.getURI().toString(), false,
					Consts.UTF_8.name());
			org.apache.commons.httpclient.HttpMethod httpMethod = method2method(request
					.getMethod());
			if (request.getMethod() == HttpMethod.TRACE) {
				httpMethod = new TraceMethod(uri.getEscapedURI());
			} else {
				httpMethod.setURI(uri);
			}
			HttpParams params = request.getParams();
			if (params != null) {
				Proxy proxy = params.getProxy();
				if (proxy != null) {
					InetSocketAddress socketAddress = (InetSocketAddress) proxy
							.address();
					httpClient.getHostConfiguration().setProxy(
							socketAddress.getHostName(),
							socketAddress.getPort());
				}
				SSLContext sslContext = params.getSSLContext();
				if (sslContext != null) {
					Protocol.registerProtocol("https", new Protocol("https",
							new SSLProtocolSocketFactory(sslContext), 443));
				}
				httpClient.getHttpConnectionManager().getParams()
						.setConnectionTimeout(params.getConnectTimeout());
				httpClient.getHttpConnectionManager().getParams()
						.setSendBufferSize(params.getChunkSize());
				httpMethod.getParams().setUriCharset(Consts.UTF_8.name());
				httpMethod.getParams().setSoTimeout(params.getSocketTimeout());
				httpMethod.getParams().setContentCharset(Consts.UTF_8.name());
			}
			com.foxinmy.weixin4j.http.HttpHeaders headers = request
					.getHeaders();
			if (headers == null) {
				headers = new HttpHeaders();
			}
			if (!headers.containsKey(HttpHeaders.HOST)) {
				headers.set(HttpHeaders.HOST, uri.getHost());
			}
			// Add default accept headers
			if (!headers.containsKey(HttpHeaders.ACCEPT)) {
				headers.set(HttpHeaders.ACCEPT, "*/*");
			}
			// Add default user agent
			if (!headers.containsKey(HttpHeaders.USER_AGENT)) {
				headers.set(HttpHeaders.USER_AGENT, "apache/httpclient3");
			}
			for (Iterator<Entry<String, List<String>>> headerIterator = headers
					.entrySet().iterator(); headerIterator.hasNext();) {
				Entry<String, List<String>> header = headerIterator.next();
				if (HttpHeaders.COOKIE.equalsIgnoreCase(header.getKey())) {
					httpMethod.setRequestHeader(header.getKey(),
							StringUtil.join(header.getValue(), ';'));
				} else {
					for (String headerValue : header.getValue()) {
						httpMethod.addRequestHeader(header.getKey(),
								headerValue != null ? headerValue : "");
					}
				}
			}
			HttpEntity entity = request.getEntity();
			if (entity != null) {
				if (entity.getContentLength() > 0l) {
					httpMethod.addRequestHeader(HttpHeaders.CONTENT_LENGTH,
							Long.toString(entity.getContentLength()));
				}
				if (entity.getContentType() != null) {
					httpMethod.addRequestHeader(HttpHeaders.CONTENT_TYPE,
							entity.getContentType().toString());
				}
				RequestEntity requestEntity = null;
				if (entity instanceof MultipartEntity) {
					ByteArrayOutputStream os = new ByteArrayOutputStream();
					entity.writeTo(os);
					os.flush();
					requestEntity = new ByteArrayRequestEntity(
							os.toByteArray(), entity.getContentType()
									.toString());
					os.close();
				} else {
					requestEntity = new InputStreamRequestEntity(
							entity.getContent(), entity.getContentType()
									.toString());
				}
				((EntityEnclosingMethod) httpMethod)
						.setRequestEntity(requestEntity);
			}
			httpClient.executeMethod(httpMethod);
			response = new HttpComponent3Response(httpMethod);
			handleResponse(response);
		} catch (IOException e) {
			throw new HttpClientException("I/O error on "
					+ request.getMethod().name() + " request for \""
					+ request.getURI().toString() + "\":" + e.getMessage(), e);
		} finally {
			if (response != null) {
				response.close();
			}
		}
		return response;
	}