專案經驗分享——Java常用工具類集合
阿新 • • 發佈:2018-12-20
寫在前面
本文涉及的工具類部分是自己編寫,另一部分是在專案裡收集的。工具類涉及資料庫連線、格式轉換、檔案操作、傳送郵件等等。提高開發效率,歡迎收藏與轉載。
資料庫連線工具類
資料庫連線工具類——僅僅獲得連線物件 ConnDB.java
package com.util;import java.sql.Connection;import java.sql.DriverManager;/** * 資料庫連線工具類——僅僅獲得連線物件 * */public class ConnDB { private static Connection conn = null; private static final String DRIVER_NAME = "com.mysql.jdbc.Driver" ; private static final String URL = "jdbc:mysql://localhost:3306/axt?useUnicode=true&characterEncoding=UTF-8"; private static final String USER_NAME = "root"; private static final String PASSWORD = "root"; public static Connection getConn(){ try { Class.forName(DRIVER_NAME); conn = DriverManager.getConnection(URL, USER_NAME, PASSWORD); } catch (Exception e) { e.printStackTrace(); } return conn; }}
資料庫連線工具類——包含取得連線和關閉資源 ConnUtil.java
package com.util;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;/** * @className: ConnUtil.java * @classDescription : 資料庫連線工具類——包含取得連線和關閉資源 * @function: * @author: Wentasy * @createTime: 2012-9-24 上午11:51:15 * @modifyTime: * @modifyReason: * @since: JDK 1.6 */public class ConnUtil { public static final String url = "jdbc:mysql://XXX.XXX.XXX.XXX:3306/dbadapter"; public static final String user = "root"; public static final String password = "XXXXXX"; /** * 得到連線 * @return * @throws SQLException * @throws ClassNotFoundException */ public static Connection establishConn() throws SQLException,ClassNotFoundException{ Class.forName("com.mysql.jdbc.Driver"); return DriverManager.getConnection(url, user, password); } /** * 關閉連線 * @param conn * @throws SQLException */ public static void close(Connection conn) throws SQLException{ if(conn != null){ conn.close(); conn = null; } } /** * 關閉PreparedStatement * @param pstmt * @throws SQLException */ public static void close(PreparedStatement pstmt) throws SQLException{ if(pstmt != null){ pstmt.close(); pstmt = null; } } /** * 關閉結果集 * @param rs * @throws SQLException */ public static void close(ResultSet rs) throws SQLException{ if(rs != null){ rs.close(); rs = null; } }}
格式轉換工具類
日期轉換工具類 CommUtil.java
package com.util;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;/** * 日期轉換工具類 */public class CommUtil { /** * 將日期格式轉換成yyyy-MM-dd的字串格式 * 返回值如:2010-10-06 * @param time 要轉換的日期 * @return */ public static String dateToString(Date time) { SimpleDateFormat formatter = new SimpleDateFormat ("yyyy-MM-dd"); //定義將日期格式要換成的格式 String stringTime = formatter.format(time); return stringTime; } /** * 將日期格式轉換成yyyyMMdd的字串格式 * 返回值如:2010-10-06 * @param time 要轉換的日期 * @return */ public static String dateTimeToString(Date time) { SimpleDateFormat formatter = new SimpleDateFormat ("yyyyMMdd"); //定義將日期格式要換成的格式 String stringTime = formatter.format(time); return stringTime; } /** * 將日期格式轉換成yyyy-MM-dd的字串格式 * 返回值如:2010-10-06 * @param time 要轉換的日期 * @return */ public static Date dateToDate(Date time) { SimpleDateFormat formatter = new SimpleDateFormat ("yyyy-MM-dd"); //定義將日期格式要換成的格式 String stringTime = formatter.format(time); Date date = null; try { date = formatter.parse(stringTime); } catch (ParseException e) { e.printStackTrace(); } return date; } /** * 得到當前時間,以字串表示 * @return */ public static String getDate(){ Date date = new Date(); return CommUtil.dateToString(date); }}
日期轉換類 DateConverter.java
package com.util;import java.text.DateFormat;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Map;import com.opensymphony.xwork2.conversion.impl.DefaultTypeConverter;/** * 日期轉換類 * */public class DateConverter extends DefaultTypeConverter { private static final DateFormat[] ACCEPT_DATE_FORMATS = { new SimpleDateFormat("dd/MM/yyyy"), new SimpleDateFormat("yyyy-MM-dd"), new SimpleDateFormat("yyyy/MM/dd") }; //支援轉換的日期格式 @Override public Object convertValue(Map context, Object value, Class toType) { if (toType == Date.class) { //瀏覽器向伺服器提交時,進行String to Date的轉換 Date date = null; String dateString = null; String[] params = (String[])value; dateString = params[0];//獲取日期的字串 for (DateFormat format : ACCEPT_DATE_FORMATS) { try { return format.parse(dateString);//遍歷日期支援格式,進行轉換 } catch(Exception e) { continue; } } return null; } else if (toType == String.class) { //伺服器向瀏覽器輸出時,進行Date to String的型別轉換 Date date = (Date)value; return new SimpleDateFormat("yyyy-MM-dd").format(date);//輸出的格式是yyyy-MM-dd } return null; }}
功能更強大的格式化工具類 FormatUtils.java
package com.util;import java.text.DecimalFormat;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;/** * 功能更強大的格式化工具類 */public class FormatUtils { private static SimpleDateFormat second = new SimpleDateFormat( "yy-MM-dd hh:mm:ss"); private static SimpleDateFormat day = new SimpleDateFormat("yyyy-MM-dd"); private static SimpleDateFormat detailDay = new SimpleDateFormat("yyyy年MM月dd日"); private static SimpleDateFormat fileName = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss"); private static SimpleDateFormat tempTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); private static SimpleDateFormat excelDate = new SimpleDateFormat("yyyy/MM/dd"); /** * 格式化excel中的時間 * @param date * @return */ public static String formatDateForExcelDate(Date date) { return excelDate.format(date); } /** * 將日期格式化作為檔名 * @param date * @return */ public static String formatDateForFileName(Date date) { return fileName.format(date); } /** * 格式化日期(精確到秒) * * @param date * @return */ public static String formatDateSecond(Date date) { return second.format(date); } /** * 格式化日期(精確到秒) * * @param date * @return */ public static String tempDateSecond(Date date) { return tempTime.format(date); } public static Date tempDateSecond(String str) { try { return tempTime.parse(str); } catch (ParseException e) { e.printStackTrace(); } return new Date(); } /** * 格式化日期(精確到天) * * @param date * @return */ public static String formatDateDay(Date date) { return day.format(date); } /** * 格式化日期(精確到天) * * @param date * @return */ public static String formatDateDetailDay(Date date) { return detailDay.format(date); } /** * 將double型別的數字保留兩位小數(四捨五入) * * @param number * @return */ public static String formatNumber(double number) { DecimalFormat df = new DecimalFormat(); df.applyPattern("#0.00"); return df.format(number); } /** * 將字串轉換成日期 * * @param date * @return * @throws Exception */ public static Date formateDate(String date) throws Exception { return day.parse(date); } /** * 將字元日期轉換成Date * @param date * @return * @throws Exception */ public static Date parseStringToDate(String date) throws Exception { return day.parse(date); } public static String formatDoubleNumber(double number) { DecimalFormat df = new DecimalFormat("#"); return df.format(number); }}
檔案操作工具類
目錄操作工具類 CopyDir.java
package com.util;import java.io.*;/** * 1,建立目的目錄。 2,遍歷源目錄。 3,遍歷過程中,建立檔案或者資料夾。 原理:其實就是改變了原始檔或者目錄的目錄頭。 * @datetime Dsc 24 */public class CopyDir { private File sDir, dDir, newDir; public CopyDir(String s, String d) { this(new File(s), new File(d)); } CopyDir(File sDir, File dDir)// c:\\Test d:\\abc { this.sDir = sDir; this.dDir = dDir; } public void copyDir() throws IOException { // 是建立目的目錄。也就是建立要拷貝的原始檔夾。Test // 獲取原始檔夾名稱。 String name = sDir.getName(); // 通過該名稱在目的目錄建立該資料夾,為了存放原始檔夾中的檔案或者資料夾。 // 將目的目錄和原始檔夾名稱,封裝成File物件。 newDir = dDir; // new File(dDir,name); // 呼叫該物件的mkdir方法。在目的目錄建立該資料夾。d:\\abc\\Test newDir.mkdir();// // 遍歷原始檔夾。 listAll(sDir); } /* * 將遍歷目錄封裝成方法。 在遍歷過程中,遇到檔案建立檔案。 遇到目錄建立目錄。 */ private void listAll(File dir) throws IOException { File[] files = dir.listFiles(); for (int x = 0; x < files.length; x++) { if (files[x].isDirectory()) { createDir(files[x]);// 呼叫建立目錄的方法。 listAll(files[x]);// 在繼續進行遞迴。進入子級目錄。 } else { createFile(files[x]);// 呼叫建立檔案的方法。 } } } /* * copy目錄。通過源目錄在目的目錄建立新目錄。 */ private void createDir(File dir) { File d = replaceFile(dir); d.mkdir(); } /* * copy檔案。 */ private void createFile(File file) throws IOException { File newFile = replaceFile(file); // copy檔案是一個數據資料傳輸的過程。需要通過流來完成。 FileInputStream fis = new FileInputStream(file); FileOutputStream fos = new FileOutputStream(newFile); byte[] buf = new byte[1024 * 2]; int num = 0; while ((num = fis.read(buf)) != -1) { fos.write(buf, 0, num); } fos.close(); fis.close(); } /* * 替換路徑。 */ private File replaceFile(File f) { // 原理是:將源目錄的父目錄(C:\\Tset),替換成目的父目錄。(d:\\abc\\Test) String path = f.getAbsolutePath();// 獲取原始檔或者資料夾的決定路徑。 // 將原始檔或者資料夾的絕對路徑替換成目的路徑。 String newPath = path.replace(sDir.getAbsolutePath(), newDir .getAbsolutePath()); // 將新的目的路徑封裝成File物件 File newFile = new File(newPath); return newFile; }}
檔案/目錄部分處理工具類 DealDir.java
package com.util;import java.io.File;import java.util.StringTokenizer;/** * 檔案/目錄 部分處理 * @createTime Dec 25, 2010 7:06:58 AM * @version 1.0 */public class DealDir { /** * 獲取檔案的字尾名並轉化成大寫 * * @param fileName * 檔名 * @return */ public String getFileSuffix(String fileName) throws Exception { return fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length()).toUpperCase(); } /** * 建立多級目錄 * * @param path * 目錄的絕對路徑 */ public void createMultilevelDir(String path) { try { StringTokenizer st = new StringTokenizer(path, "/"); String path1 = st.nextToken() + "/"; String path2 = path1; while (st.hasMoreTokens()) { path1 = st.nextToken() + "/"; path2 += path1; File inbox = new File(path2); if (!inbox.exists()) inbox.mkdir(); } } catch (Exception e) { System.out.println("目錄建立失敗" + e); e.printStackTrace(); } } /** * 刪除檔案/目錄(遞迴刪除檔案/目錄) * * @param path * 檔案或資料夾的絕對路徑 */ public void deleteAll(String dirpath) { if (dirpath == null) { System.out.println("目錄為空"); } else { File path = new File(dirpath); try { if (!path.exists()) return;// 目錄不存在退出 if (path.isFile()) // 如果是檔案刪除 { path.delete(); return; } File[] files = path.listFiles();// 如果目錄中有檔案遞迴刪除檔案 for (int i = 0; i < files.length; i++) { deleteAll(files[i].getAbsolutePath()); } path.delete(); } catch (Exception e) { System.out.println("檔案/目錄 刪除失敗" + e); e.printStackTrace(); } } } /** * 檔案/目錄 重新命名 * * @param oldPath * 原有路徑(絕對路徑) * @param newPath * 更新路徑 * @author lyf 注:不能修改上層次的目錄 */ public void renameDir(String oldPath, String newPath) { File oldFile = new File(oldPath);// 檔案或目錄 File newFile = new File(newPath);// 檔案或目錄 try { boolean success = oldFile.renameTo(newFile);// 重新命名 if (!success) { System.out.println("重新命名失敗"); } else { System.out.println("重新命名成功"); } } catch (RuntimeException e) { e.printStackTrace(); } }}
目錄處理工具類 DealWithDir.java
package com.util;import java.io.File;/** * 目錄處理工具類 * */public class DealWithDir { /** * 新建目錄 */ public static boolean newDir(String path) throws Exception { File file = new File(path); return file.mkdirs();//建立目錄 } /** * 刪除目錄 */ public static boolean deleteDir(String path) throws Exception { File file = new File(path); if (!file.exists()) return false;// 目錄不存在退出 if (file.isFile()) // 如果是檔案刪除 { file.delete(); return false; } File[] files = file.listFiles();// 如果目錄中有檔案遞迴刪除檔案 for (int i = 0; i < files.length; i++) { deleteDir(files[i].getAbsolutePath()); } file.delete(); return file.delete();//刪除目錄 } /** * 更新目錄 */ public static boolean updateDir(String path, String newPath) throws Exception { File file = new File(path); File newFile = new File(newPath); return file.renameTo(newFile); } public static void main(String d[]) throws Exception{ //deleteDir("d:/ff/dddf"); updateDir("D:\\TOOLS\\Tomcat 6.0\\webapps\\BCCCSM\\nationalExperiment/22222", "D:\\TOOLS\\Tomcat 6.0\\webapps\\BCCCSM\\nationalExperiment/224222"); } }
刪除資料夾工具類 DeleteFolder.java
package com.util;import java.io.File;/** * 刪除資料夾 * @createTime DSC 20, 2010 15:38 * @version 2.0 */public class DeleteFolder { // 刪除資料夾 // param folderPath 資料夾完整絕對路徑 public static void delFolder(String folderPath) { try { delAllFile(folderPath); // 刪除完裡面所有內容 String filePath = folderPath; filePath = filePath.toString(); java.io.File myFilePath = new java.io.File(filePath); myFilePath.delete(); // 刪除空資料夾 } catch (Exception e) { e.printStackTrace(); } } // 刪除指定資料夾下所有檔案 // param path 資料夾完整絕對路徑 public static boolean delAllFile(String path) { boolean flag = false; File file = new File(path); if (!file.exists()) { return flag; } if (!file.isDirectory()) { return flag; } String[] tempList = file.list(); File temp = null; for (int i = 0; i < tempList.length; i++) { if (path.endsWith(File.separator)) { temp = new File(path + tempList[i]); } else { temp = new File(path + File.separator + tempList[i]); } if (temp.isFile()) { temp.delete(); } if (temp.isDirectory()) { delAllFile(path + "/" + tempList[i]);// 先刪除資料夾裡面的檔案 delFolder(path + "/" + tempList[i]);// 再刪除空資料夾 flag = true; } } return flag; }}
檔案上傳工具類 UploadUtil.java
package com.util;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.InputStream;import java.io.OutputStream;import java.util.Calendar;/** * 檔案上傳工具類 * */public class UploadUtil { private static final int BUFFER_SIZE = 16 * 1024; //儲存圖片 public static synchronized void copy(File src, File newFile) { try { InputStream is = null; OutputStream os = null; try { is = new BufferedInputStream(new FileInputStream(src), BUFFER_SIZE); os = new BufferedOutputStream(new FileOutputStream(newFile), BUFFER_SIZE); byte[] buffer = new byte[BUFFER_SIZE]; while (is.read(buffer) > 0) { os.write(buffer); } } finally { if (null != is) { is.close(); } if (null != os) { os.close(); } } } catch (Exception e) { e.printStackTrace(); } } /** * 返回 年號+月號+天+時+分+秒+隨機碼 * @return */ @SuppressWarnings("static-access") public static synchronized String getTime() { Calendar calendar = Calendar.getInstance(); String year = calendar.get(calendar.YEAR) + ""; String month = (calendar.get(calendar.MONTH) + 1) + ""; String day = calendar.get(calendar.DAY_OF_MONTH) + ""; String hour = calendar.get(calendar.HOUR_OF_DAY) + ""; String minute = calendar.get(calendar.MINUTE) + ""; String second = calendar.get(calendar.SECOND) + ""; String milliSecond = calendar.get(calendar.MILLISECOND) + ""; int r = (int)(Math.random()*100000); String random = String.valueOf(r); return year + month + day + hour + minute + second + milliSecond + random+"a"; }}
其他工具類
MD5編碼工具類 MD5Code.java
package com.util;/** * MD5編碼工具類 * */public class MD5Code { static final int S11 = 7; static final int S12 = 12; static final int S13 = 17; static final int S14 = 22; static final int S21 = 5; static final int S22 = 9; static final int S23 = 14; static final int S24 = 20; static final int S31 = 4; static final int S32 = 11; static final int S33 = 16; static final int S34 = 23; static final int S41 = 6; static final int S42 = 10; static final int S43 = 15; static final int S44 = 21; static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; private long[] state = new long[4];// state (ABCD) private long[] count = new long[2];// number of bits, modulo 2^64 (lsb // first) private byte[] buffer = new byte[64]; // input buffer public String digestHexStr; private byte[] digest = new byte[16]; public String getMD5ofStr(String inbuf) { md5Init(); md5Update(inbuf.getBytes(), inbuf.length()); md5Final(); digestHexStr = ""; for (int i = 0; i < 16; i++) { digestHexStr += byteHEX(digest[i]); } return digestHexStr; } public MD5Code() { md5Init(); return; } private void md5Init() { count[0] = 0L; count[1] = 0L; // /* Load magic initialization constants. state[0] = 0x67452301L; state[1] = 0xefcdab89L; state[2] = 0x98badcfeL; state[3] = 0x10325476L; return; } private long F(long x, long y, long z) { return (x & y) | ((~x) & z); } private long G(long x, long y, long z) { return (x & z) | (y & (~z)); } private long H(long x, long y, long z) { return x ^ y ^ z; } private long I(long x, long y, long z) { return y ^ (x | (~z)); } private long FF(long a, long b, long c, long d, long x, long s, long ac) { a += F(b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; } private long GG(long a, long b, long c, long d, long x, long s, long ac) { a += G(b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; } private long HH(long a, long b, long c, long d, long x, long s, long ac) { a += H(b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; } private long II(long a, long b, long c, long d, long x, long s, long ac) { a += I(b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; } private void md5Update(byte[] inbuf, int inputLen) { int i, index, partLen; byte[] block = new byte[64]; index = (int) (count[0] >>> 3) & 0x3F; // /* Update number of bits */ if ((count[0] += (inputLen << 3)) < (inputLen << 3)) count[1]++; count[1] += (inputLen >>> 29); partLen = 64 - index; // Transform as many times as possible. if (inputLen >= partLen) { md5Memcpy(buffer, inbuf, index, 0, partLen); md5Transform(buffer); for (i = partLen; i + 63 < inputLen; i += 64) { md5Memcpy(block, inbuf, 0, i, 64); md5Transform(block); } index = 0; } else i = 0; // /* Buffer remaining input */ md5Memcpy(buffer, inbuf, index, i, inputLen - i); } private void md5Final() { byte[] bits = new byte[8]; int index, padLen; // /* Save number of bits */ Encode(bits, count, 8); // /* Pad out to 56 mod 64. index = (int) (count[0] >>> 3) & 0x3f; padLen = (index < 56) ? (56 - index) : (120 - index); md5Update(PADDING, padLen); // /* Append length (before padding) */ md5Update(bits, 8); // /* Store state in digest */ Encode(digest, state, 16); } private void md5Memcpy(byte[] output, byte[] input, int outpos, int inpos, int len) { int i; for (i = 0; i < len; i++) output[outpos + i] = input[inpos + i]; } private void md5Transform(byte block[]) { long a = state[0], b = state[1], c = state[2], d = state[3]; long[] x = new long[16]; Decode(x, block, 64); /* Round 1 */ a = FF(a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */ d = FF(d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */ c = FF(c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */ b = FF(b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */ a = FF(a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */ d = FF(d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */ c = FF(c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */ b = FF(b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */ a = FF(a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */ d = FF(d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */ c = FF(c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */ b = FF(b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */ a = FF(a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */ d = FF(d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */ c = FF(c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */ b = FF(b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */ /* Round 2 */ a = GG(a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */ d = GG(d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */ c = GG(c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */ b = GG(b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */ a = GG(a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */ d = GG(d, a, b, c, x[10], S22, 0x2441453L); /* 22 */ c = GG(c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */ b = GG(b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */ a = GG(a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */ d = GG(d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */ c = GG(c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */ b = GG(b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */ a = GG(a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */ d = GG(d, a, b, c, x[2], S22,