java常用的工具方法

常用的工具方法字节数组转16进制字符串加密算法进制之间的转换

常用的工具方法

字节数组转16进制字符串

``` 1. public static String toHexString(byte[] data) { if(data == null) { return null; } StringBuilder r = new StringBuilder(data.length*2); for ( byte b : data) { r.append(hexCode[(b >> 4) & 0xF]); r.append(hexCode[(b & 0xF)]); } return r.toString(); } ```

加密算法

1.SHA1

private static byte[] getSHA1Digest(String data) throws IOException { byte[] bytes = null; try { MessageDigest md = MessageDigest.getInstance("SHA-1"); bytes = md.digest(data.getBytes("UTF-8")); } catch (GeneralSecurityException gse) { throw new IOException(gse); } return bytes; }

进制之间的转换

1.二进制转十六进制字符串

/** * 二进制转十六进制字符串 * * @param bytes * @return */ private static String byte2hex(byte[] bytes) { StringBuilder sign = new StringBuilder(); for (int i = 0; i < bytes.length; i++) { String hex = Integer.toHexString(bytes[i] & 0xFF); if (hex.length() == 1) { sign.append("0"); } sign.append(hex.toUpperCase()); } return sign.toString(); } ``` 2.将十六进制数组转为二进制字节数组 /** * 将十六进制数组转为二进制字节数组 * @Title hexToBt4 * @param hex */ public static String hexToBt4(String hex){ String binary = ""; if (hex.equals("0")) { binary = "0000"; } else if (hex.equals("1")) { binary = "0001"; } if (hex.equals("2")) { binary = "0010"; } if (hex.equals("3")) { binary = "0011"; } if (hex.equals("4")) { binary = "0100"; } if (hex.equals("5")) { binary = "0101"; } if (hex.equals("6")) { binary = "0110"; } if (hex.equals("7")) { binary = "0111"; } if (hex.equals("8")) { binary = "1000"; } if (hex.equals("9")) { binary = "1001"; } if (hex.equals("A")) { binary = "1010"; } if (hex.equals("B")) { binary = "1011"; } if (hex.equals("C")) { binary = "1100"; } if (hex.equals("D")) { binary = "1101"; } if (hex.equals("E")) { binary = "1110"; } if (hex.equals("F")) { binary = "1111"; } return binary; } ## 数组排序 1数组各个元素的自然排序 ``` /** * 将数组各个元素的自然排序后拼接成一个用逗号分隔的字符串 * @Title naturalOrdering */ public static String naturalOrdering(String[] strArray) { String resultStr = ""; if (strArray != null && strArray.length > 0) { Arrays.sort(strArray); // System.out.println(strArray); for (int i = 0; i < strArray.length; i++) { resultStr += i == 0 ? strArray[i] : "," + strArray[i]; } } return resultStr; } ``` ## 请求 1.post请求，参数为json字符串 /** * post请求，参数为json字符串 * post请求，参数为json字符串 * @param url 请求地址 * @param jsonString json字符串 * @return 响应 */ public static String postJson(String url,String jsonString) { String result = null; CloseableHttpClient httpClient = HttpClients.createDefault(); HttpPost post = new HttpPost(url); CloseableHttpResponse response = null; try { post.setEntity(new ByteArrayEntity(jsonString.getBytes("UTF-8"))); post.setHeader("Content-Type", "application/json"); response = httpClient.execute(post); if(response != null && response.getStatusLine().getStatusCode() == 200) { HttpEntity entity = response.getEntity(); result = entityToString(entity); } return result; } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); }finally { try { httpClient.close(); if(response != null) { response.close(); } } catch (IOException e) { e.printStackTrace(); } } return null; }

2.向指定 URL 发送POST方法的请求

/** * 向指定 URL 发送POST方法的请求 * * @param url * 发送请求的 URL * @return 所代表远程资源的响应结果 */ public static String sendPost(String url, JSONObject json) { HttpClient client = HttpClientBuilder.create().build(); HttpPost post = new HttpPost(url); post.setHeader("Content-Type", "application/json"); post.addHeader("Authorization", "Basic YWRtaW46"); String result = ""; try { String tt = json.toString(); StringEntity s = new StringEntity(json.toString(), "utf-8"); s.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json")); post.setEntity(s); // 发送请求 HttpResponse httpResponse = client.execute(post); // 获取响应输入流 InputStream inStream = httpResponse.getEntity().getContent(); BufferedReader reader = new BufferedReader(new InputStreamReader( inStream, "utf-8")); StringBuilder strber = new StringBuilder(); String line = null; while ((line = reader.readLine()) != null) strber.append(line + "\n"); inStream.close(); result = strber.toString(); System.out.println(result); if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) { System.out.println("请求服务器成功，做相应处理"); } else { System.out.println("请求服务端失败"); } } catch (Exception e) { System.out.println("请求异常"); throw new RuntimeException(e); } return result; }

2.向指定 URL 发送GET方法的请求

/** * GET方法的请求 * 获取请求接口的返回信息 * * @param url * 请求接口时需要传入的URL */ public static String sendRequest(String url) { InputStream inputStream = null; BufferedReader bufferedReader = null; HttpURLConnection httpURLConnection = null; try { URL requestURL = new URL(url); // 获取连接 httpURLConnection = (HttpURLConnection) requestURL.openConnection(); httpURLConnection.setConnectTimeout(10000); //建立连接的超时时间，毫秒 httpURLConnection.setReadTimeout(25000); //获得返回的超时时间，毫秒 httpURLConnection.setRequestMethod("GET"); // 通过输入流获取请求的内容 inputStream = httpURLConnection.getInputStream(); bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8")); String temp = null; StringBuffer stringBuffer = new StringBuffer(); // 循环读取返回的结果 while ((temp = bufferedReader.readLine()) != null) { stringBuffer.append(temp); } return stringBuffer.toString(); } catch (Exception e) { e.printStackTrace(); }finally { //断开连接 if (httpURLConnection!=null) { httpURLConnection.disconnect(); } // 关闭流 if(bufferedReader!=null){ try { bufferedReader.close(); } catch (IOException e) { e.printStackTrace(); } } if(inputStream!=null){ try { inputStream.close(); } catch (IOException e) { e.printStackTrace(); } } } return null; }