java常用工具类小结，更新中

/**
 * 生成指定长度的随机数
 *
 * @param length
 * @return
 */
public static int genRandomNum(int length) {
    int num = 1;
    double random = Math.random();
    if (random < 0.1) {
        random = random + 0.1;
    }
    for (int i = 0; i < length; i++) {
        num = num * 10;
    }
    return (int) ((random * num));
}

/**
 * 判断是否为空字符串
 * @param str
 * @return 如果为空，则返回true
 */
public static boolean isEmpty(String str){
    return str == null || str.trim().length() == 0;
}

/**
 * 判断collection是否为空
 * @param collection
 * @return 如果为空，则返回true
 */
public static boolean isEmpty(Collection collection){
    //return CollectionUtils.isEmpty(collection);
    return collection == null || collection.isEmpty();
}

/**
 * 判断map是否为空
 * @param map
 * @return
 */
public static boolean isEmpty(Map map){
    return map == null || map.isEmpty();
}

/**
 * 判断数组是否非空
 * @param array
 * @return
 */
public static boolean isEmpty(Object[] array){
    return array==null||array.length==0;
}

/**
 * 获取当前时间
 * @param 
 * @return yyyy-MM-dd 
 */
public static String getDate() {
    Date d = new Date();  
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  
    String Now = sdf.format(d);
    return Now;   
}

/**
 * 获取当前时间(适用于生成水流)
 * @param 
 * @return yyyy-MM-dd HH:mm:ss
 */
public static String getTime() {
    Date d = new Date();  
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmssSSS");  
    String time = sdf.format(d);
    return time;   
}

/**
 * 获取当前时间
 * @param 
 * @return yyyy-MM-dd HH:mm:ss
 */
public static String getNow() {
    Date d = new Date();  
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
    String time = sdf.format(d);
    return time;   
}


/**
 * 
 * @方法名：encryption
 * @方法描述：MD5加密32位小写
 * @param encryptStr 明文
 * @return 32位小写密文
 */
public static String encryption(String encryptStr) {
    String m_algorithm = "MD5";
    String re_md5 = new String();
    try {
        MessageDigest md = MessageDigest.getInstance(m_algorithm);
        md.update(encryptStr.getBytes("UTF-8"));
        byte b[] = md.digest();
        int i;
        StringBuilder builder = new StringBuilder("");
        for (int offset = 0; offset < b.length; offset++) {
            i = b[offset];
            if (i < 0)
                i += 256;
            if (i < 16)
                builder.append("0");
            builder.append(Integer.toHexString(i));
        }
        re_md5 = builder.toString();
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    return re_md5;
}


/**
 * 
 * @方法名：ENCRYPTION
 * @方法描述：MD5加密32位大写
 * @param encryptStr 明文
 * @return 32位大写密文
 */
public static String ENCRYPTION(String encryptStr) {
    char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
    try {
        byte[] btInput = encryptStr.getBytes();
        // 获得MD5摘要算法的 MessageDigest 对象
        MessageDigest mdInst = MessageDigest.getInstance("MD5");
        // 使用指定的字节更新摘要
        mdInst.update(btInput);
        // 获得密文
        byte[] md = mdInst.digest();
        // 把密文转换成十六进制的字符串形式
        int j = md.length;
        char str[] = new char[j * 2];
        int k = 0;
        for (int i = 0; i < j; i++) {
            byte byte0 = md[i];
            str[k++] = hexDigits[byte0 >>> 4 & 0xf];
            str[k++] = hexDigits[byte0 & 0xf];
        }
        return new String(str);
    }
    catch (Exception e) {
        return null;
    }
}

/**
 * 
 * @方法名：encryption16
 * @方法描述:MD5加密16位小写
 * @param encryptStr 明文
 * @return 16位小写密文
 */
public static String encryption16(String encryptStr) {
    return encryption(encryptStr).substring(8, 24);
}

/**
 * 
 * @方法名：ENCRYPTION16
 * @方法描述: MD5加密16位大写
 * @param encryptStr 明文
 * @return 16位大写密文
 */
public static String ENCRYPTION16(String encryptStr) {
    return ENCRYPTION(encryptStr).substring(8, 24);
}

/**

• Double/float转字符
• @param Double/float
  */
  public static String formatMoney2Str(Double money) {
  java.text.DecimalFormat df = new java.text.DecimalFormat(“0.00”);
  return df.format(money);
  }

public static String formatMoney2Str(float money) {
    java.text.DecimalFormat df = new java.text.DecimalFormat("0.00");
    return df.format(money);
}    

/**

• 一维条形码类

• @data 2019-12-23

• @author Gaara
  /
  public class barCodeUtil {
  /*
  *一维条形码

  • @param msg
  • @param path
    */
    @SuppressWarnings(“resource”)
    public static void getBarCode(String msg,String path){
    try {
    File file=new File(path);
    OutputStream ous=new FileOutputStream(file);
    if("".equals(msg)||ous==null) {
    return;
    }
    //选择条形码类型(好多类型可供选择)
    Code128Bean bean=new Code128Bean();
    //设置长宽
    final double moduleWidth=0.20;
    final int resolution=150;
    bean.setModuleWidth(moduleWidth);
    bean.doQuietZone(false);
    String format = “image/png”;
    // 输出流
    BitmapCanvasProvider canvas = new BitmapCanvasProvider(ous, format,
    resolution, BufferedImage.TYPE_BYTE_BINARY, false, 0);
    //生成条码
    bean.generateBarcode(canvas,msg);
    canvas.finish();
    }catch (IOException e) {
    throw new RuntimeException(e);
    }

  }

  public static void main(String[] args) {
  String msg = “My name is Gaara”;
  String path = “E:/barCode/barCode.png”;
  barCodeUtil.getBarCode(msg,path);
  }
  }

---

import java.awt.BasicStroke;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Shape;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.Hashtable;
import javax.imageio.ImageIO;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class QRCodeUtil {
private static final String CHARSET = “utf-8”;
private static final String FORMAT_NAME = “JPG”;
// 二维码尺寸
private static final int QRCODE_SIZE = 300;
// LOGO宽度
private static final int WIDTH = 60;
// LOGO高度
private static final int HEIGHT = 60;

@SuppressWarnings({ "unchecked", "rawtypes" })
private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception {
	Hashtable hints = new Hashtable();
	hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
	hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
	hints.put(EncodeHintType.MARGIN, 1);
	BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE,
			hints);
	int width = bitMatrix.getWidth();
	int height = bitMatrix.getHeight();
	BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
	for (int x = 0; x < width; x++) {
		for (int y = 0; y < height; y++) {
			image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
		}
	}
	if (imgPath == null || "".equals(imgPath)) {
		return image;
	}
	// 插入图片
	QRCodeUtil.insertImage(image, imgPath, needCompress);
	return image;
}

private static void insertImage(BufferedImage source, String imgPath, boolean needCompress) throws Exception {
	File file = new File(imgPath);
	if (!file.exists()) {
		System.err.println("" + imgPath + "   该文件不存在！");
		return;
	}
	Image src = ImageIO.read(new File(imgPath));
	int width = src.getWidth(null);
	int height = src.getHeight(null);
	if (needCompress) { // 压缩LOGO
		if (width > WIDTH) {
			width = WIDTH;
		}
		if (height > HEIGHT) {
			height = HEIGHT;
		}
		Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH);
		BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		Graphics g = tag.getGraphics();
		g.drawImage(image, 0, 0, null); // 绘制缩小后的图
		g.dispose();
		src = image;
	}
	// 插入LOGO
	Graphics2D graph = source.createGraphics();
	int x = (QRCODE_SIZE - width) / 2;
	int y = (QRCODE_SIZE - height) / 2;
	graph.drawImage(src, x, y, width, height, null);
	Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
	graph.setStroke(new BasicStroke(3f));
	graph.draw(shape);
	graph.dispose();
}

public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception {
	BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
	mkdirs(destPath);
	// String file = new Random().nextInt(99999999)+".jpg";
	// ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
	ImageIO.write(image, FORMAT_NAME, new File(destPath));
}

public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
	BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
	return image;
}

public static void mkdirs(String destPath) {
	File file = new File(destPath);
	// 当文件夹不存在时，mkdirs会自动创建多层目录，区别于mkdir．(mkdir如果父目录不存在则会抛出异常)
	if (!file.exists() && !file.isDirectory()) {
		file.mkdirs();
	}
}

public static void encode(String content, String imgPath, String destPath) throws Exception {
	QRCodeUtil.encode(content, imgPath, destPath, false);
}
// 被注释的方法
/*
 * public static void encode(String content, String destPath, boolean
 * needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath,
 * needCompress); }
 */

public static void encode(String content, String destPath) throws Exception {
	QRCodeUtil.encode(content, null, destPath, false);
}

public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
		throws Exception {
	BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
	ImageIO.write(image, FORMAT_NAME, output);
}

public static void encode(String content, OutputStream output) throws Exception {
	QRCodeUtil.encode(content, null, output, false);
}

public static String decode(File file) throws Exception {
	BufferedImage image;
	image = ImageIO.read(file);
	if (image == null) {
		return null;
	}
	BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
	BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
	Result result;
	Hashtable hints = new Hashtable();
	hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
	result = new MultiFormatReader().decode(bitmap, hints);
	String resultStr = result.getText();
	return resultStr;
}

public static String decode(String path) throws Exception {
	return QRCodeUtil.decode(new File(path));
}

}

package com.gaara.utils;

public class QRCodeTest {

public static void main(String[] args) throws Exception {
	// 存放在二维码中的内容
	String text = "MOM系统二维码";
	// 嵌入二维码的图片路径
	String imgPath = "E:/qrCode/MOM.jpg";
	// 生成的二维码的路径及名称
	String destPath = "E:/qrCode/qrcode/pic1.jpg";
	//生成二维码
	QRCodeUtil.encode(text, imgPath, destPath, true);
	// 解析二维码
	String str = QRCodeUtil.decode(destPath);
	// 打印出解析出的内容
	System.out.println("二维码解析的内容为:"+"\n" +str);

}

}

package com.taotao.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;

/**

• ftp上传下载工具类

• Title: FtpUtil

• Description:

• Company: www.itcast.com

• @author Gaara

• @date 2015年7月29日下午8:11:51

• @version 1.0
  */
  public class FtpUtil {

  /**

  • Description: 向FTP服务器上传文件
  • @param host FTP服务器hostname
  • @param port FTP服务器端口
  • @param username FTP登录账号
  • @param password FTP登录密码
  • @param basePath FTP服务器基础目录
  • @param filePath FTP服务器文件存放路径。例如分日期存放：/2015/01/01。文件的路径为basePath+filePath
  • @param filename 上传到FTP服务器上的文件名
  • @param input 输入流
  • @return 成功返回true，否则返回false
    */
    public static boolean uploadFile(String host, int port, String username, String password, String basePath,
    String filePath, String filename, InputStream input) {
    boolean result = false;
    FTPClient ftp = new FTPClient();
    try {
    int reply;
    ftp.connect(host, port);// 连接FTP服务器
    // 如果采用默认端口，可以使用ftp.connect(host)的方式直接连接FTP服务器
    ftp.login(username, password);// 登录
    reply = ftp.getReplyCode();
    if (!FTPReply.isPositiveCompletion(reply)) {
    ftp.disconnect();
    return result;
    }
    //切换到上传目录
    if (!ftp.changeWorkingDirectory(basePath+filePath)) {
    //如果目录不存在创建目录
    String[] dirs = filePath.split("/");
    String tempPath = basePath;
    for (String dir : dirs) {
    if (null == dir || “”.equals(dir)) continue;
    tempPath += “/” + dir;
    if (!ftp.changeWorkingDirectory(tempPath)) {
    if (!ftp.makeDirectory(tempPath)) {
    return result;
    } else {
    ftp.changeWorkingDirectory(tempPath);
    }
    }
    }
    }
    //设置上传文件的类型为二进制类型
    ftp.setFileType(FTP.BINARY_FILE_TYPE);
    //上传文件
    if (!ftp.storeFile(filename, input)) {
    return result;
    }
    input.close();
    ftp.logout();
    result = true;
    } catch (IOException e) {
    e.printStackTrace();
    } finally {
    if (ftp.isConnected()) {
    try {
    ftp.disconnect();
    } catch (IOException ioe) {
    }
    }
    }
    return result;
    }

  /**

  • Description: 从FTP服务器下载文件

  • @param host FTP服务器hostname

  • @param port FTP服务器端口

  • @param username FTP登录账号

  • @param password FTP登录密码

  • @param remotePath FTP服务器上的相对路径

  • @param fileName 要下载的文件名

  • @param localPath 下载后保存到本地的路径

  • @return
    */
    public static boolean downloadFile(String host, int port, String username, String password, String remotePath,
    String fileName, String localPath) {
    boolean result = false;
    FTPClient ftp = new FTPClient();
    try {
    int reply;
    ftp.connect(host, port);
    // 如果采用默认端口，可以使用ftp.connect(host)的方式直接连接FTP服务器
    ftp.login(username, password);// 登录
    reply = ftp.getReplyCode();
    if (!FTPReply.isPositiveCompletion(reply)) {
    ftp.disconnect();
    return result;
    }
    ftp.changeWorkingDirectory(remotePath);// 转移到FTP服务器目录
    FTPFile[] fs = ftp.listFiles();
    for (FTPFile ff : fs) {
    if (ff.getName().equals(fileName)) {
    File localFile = new File(localPath + “/” + ff.getName());

     		OutputStream is = new FileOutputStream(localFile);
     		ftp.retrieveFile(ff.getName(), is);
     		is.close();
     	}
     }
    
     ftp.logout();
     result = true;
    

    } catch (IOException e) {
    e.printStackTrace();
    } finally {
    if (ftp.isConnected()) {
    try {
    ftp.disconnect();
    } catch (IOException ioe) {
    }
    }
    }
    return result;
    }

  public static void main(String[] args) {
  try {
  FileInputStream in=new FileInputStream(new File(“D:\temp\image\gaigeming.jpg”));
  boolean flag = uploadFile(“192.168.25.133”, 21, “ftpuser”, “ftpuser”, “/home/ftpuser/www/images”,"/2015/01/21", “gaigeming.jpg”, in);
  System.out.println(flag);
  } catch (FileNotFoundException e) {
  e.printStackTrace();
  }
  }
  }