JAVA入坑之高级文件处理

不念不忘少年蓝@ 2024-04-17 11:48 29阅读 0赞

## 一、图片文件简介及解析 ##

### 1.1图形图像基础概念 ###

![b484a41470b541aebeefce9c377a4acb.png][]

### 1.2JAVA图形图像关键类 ###

### ![c1d31e13ffea43cf9c4d78d1d7872d34.png][] ###

![618ec75897554f32927b42e30577a593.png][]

### 1.3图形的基本操作 ###

package org.example;
    
    
    import javax.imageio.ImageIO;
    import javax.imageio.ImageReadParam;
    import javax.imageio.ImageReader;
    import javax.imageio.stream.ImageInputStream;
    import java.awt.*;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.FileInputStream;
    import java.util.Iterator;
    
    public class ImageTest {
        public static void main(String[] args) throws Exception {
            readAndWrite(); // 读取并写入图片
            readComparison(); // 图片读取速度对比
            cropImage("D://桌面//1.png", "D://桌面//4.png", 750, 250, 700, 300, "png", "png");
            combineImagesHorizontally("D://桌面//1.png", "D://桌面//1.png", "jpg", "D://桌面//4.png");
            combineImagesVertically("D://桌面//1.png","D://桌面//1.png","jpg", "D://桌面//5.png");
        }
        public static void readAndWrite() throws Exception {
            // 读取和写入 PNG 图片
            BufferedImage image = ImageIO.read(new File("D://桌面//1.png"));
            System.out.println("高度: " + image.getHeight()); // 图片高度（像素）
            System.out.println("宽度: " + image.getWidth()); // 图片宽度（像素）
            ImageIO.write(image, "png", new File("D://桌面//3.png"));
        }
        public static void readComparison() throws Exception {
            System.out.println("===========加载速度测试==============");
            // 使用 ImageIO 读取 PNG 图片
            long startTime = System.nanoTime();
            BufferedImage image = ImageIO.read(new File("D://桌面//1.png"));
            System.out.println("高度: " + image.getHeight()); // 图片高度（像素）
            System.out.println("宽度: " + image.getWidth()); // 图片宽度（像素）
            long endTime = System.nanoTime();
            System.out.println("使用 ImageIO 读取时间: " + (endTime - startTime) / 1000000.0 + "毫秒");
            // 使用 PNG ImageReader 读取 PNG 图片
            startTime = System.nanoTime();
            Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName("png");
            ImageReader reader = readers.next(); // 使用正确的格式读取器
            System.out.println(reader.getClass().getName());
            ImageInputStream iis = ImageIO.createImageInputStream(new File("D://桌面//1.png"));
            reader.setInput(iis, true);
            System.out.println("使用 ImageReader 获得的高度:" + reader.getHeight(0)); // 从 ImageReader 获取图片高度
            System.out.println("使用 ImageReader 获得的宽度:" + reader.getWidth(0)); // 从 ImageReader 获取图片宽度
            endTime = System.nanoTime();
            System.out.println("使用 ImageReader 读取时间: " + (endTime - startTime) / 1000000.0 + "毫秒");
        }
        public static void cropImage(String fromPath, String toPath, int x, int y, int width, int height, String readImageFormat, String writeImageFormat) throws Exception {
            FileInputStream fis = null;
            ImageInputStream iis = null;
            try {
                // 读取原始图片文件
                fis = new FileInputStream(fromPath);
                Iterator<ImageReader> it = ImageIO.getImageReadersByFormatName(readImageFormat);
                ImageReader reader = it.next();
                iis = ImageIO.createImageInputStream(fis);
                reader.setInput(iis, true);
                // 定义一个矩形 并放入切割参数中
                ImageReadParam param = reader.getDefaultReadParam();
                Rectangle rect = new Rectangle(x, y, width, height);
                param.setSourceRegion(rect);
                // 从源文件读取一个矩形大小的图像
                BufferedImage bi = reader.read(0, param);
                // 写入到目标文件
                ImageIO.write(bi, writeImageFormat, new File(toPath));
            } finally {
                fis.close();
                iis.close();
            }
        }
        public static void combineImagesHorizontally(String firstPath, String secondPath, String imageFormat, String toPath) {
            try {
                File first = new File(firstPath);
                BufferedImage imageOne = ImageIO.read(first);
                int width1 = imageOne.getWidth();
                int height1 = imageOne.getHeight();
                int[] firstRGB = imageOne.getRGB(0, 0, width1, height1, null, 0, width1);
                File second = new File(secondPath);
                BufferedImage imageTwo = ImageIO.read(second);
                int width2 = imageTwo.getWidth();
                int height2 = imageTwo.getHeight();
                int[] secondRGB = imageTwo.getRGB(0, 0, width2, height2, null, 0, width2);
                // 生成新图片
                int height3 = Math.max(height1, height2);
                int width3 = width1 + width2;
                BufferedImage imageNew = new BufferedImage(width3, height3, BufferedImage.TYPE_INT_RGB);
                // 设置左半部分的RGB从 (0, 0) 开始
                imageNew.setRGB(0, 0, width1, height1, firstRGB, 0, width1);
                // 设置右半部分的RGB从 (width1, 0) 开始
                imageNew.setRGB(width1, 0, width2, height2, secondRGB, 0, width2);
                // 保存图片
                ImageIO.write(imageNew, imageFormat, new File(toPath));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        public static void combineImagesVertically(String firstPath, String secondPath,String imageFormat, String toPath){
            try{
    //读取第一张图片
                File  first  =  new  File(firstPath);
                BufferedImage  imageOne = ImageIO.read(first);
                int  width1  =  imageOne.getWidth();//图片宽度
                int  height1  =  imageOne.getHeight();//图片高度
    //从图片中读取RGB
                int[]  firstRGB  =  new  int[width1*height1];
                firstRGB  =  imageOne.getRGB(0,0,width1,height1,firstRGB,0,width1);
    //对第二张图片做相同的处理
                File  second  =  new  File(secondPath);
                BufferedImage  imageTwo  =  ImageIO.read(second);
                int width2 = imageTwo.getWidth();
                int height2 = imageTwo.getHeight();
                int[]   secondRGB  =  new  int[width2*height2];
                secondRGB  =  imageTwo.getRGB(0,0,width2,height2,secondRGB,0,width2);
    //生成新图片
                int width3 = (width1>width2)?width1:width2; //挑选宽度大的，作为目标文件的宽度
                int height3 = height1+height2; //高度，两张图片相加
                BufferedImage  imageNew  =  new  BufferedImage(width3,height3,BufferedImage.TYPE_INT_RGB);
    //设置上半部分的RGB 从 开始
                imageNew.setRGB(0,0,width1,height1,firstRGB,0,width1);
    //设置下半部分的RGB 从(0， height1) 开始
                imageNew.setRGB(0,height1,width2,height2,secondRGB,0,width2);
    //保存图片
                ImageIO.write(imageNew, imageFormat, new File(toPath));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

### 1.4验证码的生成 ###

![b4741329d0524edca3e154c202f982db.png][]

package org.example;
    
    import java.awt.Color;
    import java.awt.Font;
    import java.awt.Graphics2D;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.IOException;
    import java.util.Random;
    import javax.imageio.ImageIO;
    
    public class ValidateCodeTest {
        static char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'M', 'N', 'P', 'Q', 'R', 'S', 'T',
                'U', 'V', 'W', 'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9' };
        static int charNum = codeSequence.length;
    
        public static void main(String[] a) throws IOException {
            generateCode("D://桌面//6.png");
        }
    
        public static void generateCode(String filePath) throws IOException {
            // 首先定义验证码图片框
            int width = 800; // 验证码图片的宽度
            int height = 200; // 验证码图片的高度
    
            BufferedImage buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    
            // 定义图片上的图形和干扰线
            Graphics2D gd = buffImg.createGraphics();
            gd.setColor(Color.LIGHT_GRAY); // 将图像填充为浅灰色
            gd.fillRect(0, 0, width, height);
            gd.setColor(Color.BLACK); // 画边框。
            gd.drawRect(0, 0, width - 1, height - 1);
    
            // 随机产生16条灰色干扰线，使图像中的认证码不易识别
            gd.setColor(Color.GRAY);
            Random random = new Random();
            for (int i = 0; i < 16; i++) {
                int x = random.nextInt(width);
                int y = random.nextInt(height);
                int x1 = random.nextInt(12);
                int y1 = random.nextInt(12);
                gd.drawLine(x, y, x + x1, y + y1);
            }
    
            // 计算字的位置坐标
            int codeCount = 4; // 字符个数
            int fontHeight = height - 10; // 字体高度
            int codeX = (width - 4) / (codeCount + 1); // 第一个字符的x坐标
            int codeY = height - 7;
    
            // 创建字体
            Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);
            gd.setFont(font);
    
            // 随机产生codeCount个数字的验证码
            for (int i = 0; i < codeCount; i++) {
                String strRand = String.valueOf(codeSequence[random.nextInt(charNum)]);
                int red = random.nextInt(255);
                int green = random.nextInt(255);
                int blue = random.nextInt(255);
                gd.setColor(new Color(red, green, blue));
                gd.drawString(strRand, (i + 1) * codeX, codeY);
            }
    
            // 保存图片
            ImageIO.write(buffImg, "jpg", new File(filePath));
        }
    }

## 二、条形码和二维码简介及解析 ##

### 2.1条形码 ###

![c6cf0a365d1d4f99ba5a8fd07a153aec.png][]

### 2.2二维码 ###

### ![b09322fadb894bc7819efbc4915b3433.png][] ###

### 2.3相关包 ###

### ![476bbebee9d242a19db46ca5ba1431a7.png][] ###

package org.example;
    
    import com.google.zxing.BarcodeFormat;
    import com.google.zxing.BinaryBitmap;
    import com.google.zxing.DecodeHintType;
    import com.google.zxing.LuminanceSource;
    import com.google.zxing.MultiFormatReader;
    import com.google.zxing.MultiFormatWriter;
    import com.google.zxing.Result;
    import com.google.zxing.client.j2se.MatrixToImageWriter; // 引入 MatrixToImageWriter 类
    import com.google.zxing.common.BitMatrix;
    import com.google.zxing.common.HybridBinarizer;
    import javax.imageio.ImageIO;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.util.HashMap;
    import java.util.Map;
    
    public class BarCodeTest {
    
        /**
         * 根据 code 生成相应的一维码
         *
         * @param file   一维码目标文件
         * @param code   一维码内容
         * @param width  图片宽度
         * @param height 图片高度
         */
        public static void generateCode(File file, String code, int width, int height) {
            // 定义位图矩阵 BitMatrix
            BitMatrix matrix = null;
            try {
                // 使用 CODE_128 格式进行编码生成一维码
                MultiFormatWriter writer = new MultiFormatWriter();
                matrix = writer.encode(code, BarcodeFormat.CODE_128, width, height, null);
            } catch (Exception e) {
                e.printStackTrace();
            }
    
            // 将位图矩阵 BitMatrix 保存为图片
            try (FileOutputStream outStream = new FileOutputStream(file)) {
                ImageIO.write(MatrixToImageWriter.toBufferedImage(matrix), "png", outStream);
                outStream.flush();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
        public static void readCode(File file) {
            try {
                BufferedImage image = ImageIO.read(file);
                if (image == null) {
                    return;
                }
                LuminanceSource source = new BufferedImageLuminanceSource(image);
                BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
                Map<DecodeHintType, Object> hints = new HashMap<>();
                hints.put(DecodeHintType.CHARACTER_SET, "GBK");
                hints.put(DecodeHintType.PURE_BARCODE, Boolean.TRUE);
                hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
                Result result = new MultiFormatReader().decode(bitmap, hints);
                System.out.println("条形码内容：" + result.getText());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
        public static void main(String[] args) throws Exception {
            // generateCode(new File("1dcode.png"), "123456789012", 500, 250);
            readCode(new File("1dcode.png"));
        }
    }

![356636ea73264d65a402569d6052e680.png][]

## 三、Docx简介及解析 ##

### 3.1Docx简介 ###

![59ac5f92b1fa47df8a8f78a0bd396e02.png][]

### ![fb0421fb0bfa4dddaa1ba2f1f97910e2.png][] 3.2POI库![45114c8179d8420b94ea3ce3993019cb.png][] ###

## 四、表格文件简介及解析 ##

> ●xls/xlsx 文件(Microsoft Excel)  
> ●CSV文件(Comma Seperated Values文件)

### 4.1xls/xlsx 文件 ###

![0d1d43c686164b0b9e126d591d5f7f05.png][]

### 4.2相关包 ###

![16a6f7aee71345ab822fd4784252dc51.png][]

### ![38b2676e0e294e7e8ab83b9a6db2495c.png][] 4.3CSV文件![e90c70de047f409b9472b50f18fc8408.png][] ###

## 五、 PDF简介及解析 ##

### 5.1 PDF简介 ###

![960eb835f48d4015abd1118b80f0206f.png][]

### 5.2第三方包 ###

### ![5d1b4b35748746f9b942792493fae2a2.png][]![30844bcfafa1447a944b43352efdc49b.png][] ###

[b484a41470b541aebeefce9c377a4acb.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/588966f9e222426981273e63442c4d18.png
[c1d31e13ffea43cf9c4d78d1d7872d34.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/068c18fe6e56486e9013f23863e6e352.png
[618ec75897554f32927b42e30577a593.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/ad3e1b5aa276491780acede09fa50ecc.png
[b4741329d0524edca3e154c202f982db.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/5867ca41d9fb42958b05ee4cf71cd4d0.png
[c6cf0a365d1d4f99ba5a8fd07a153aec.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/5c86a42b60884f28bb9cb7c1239c1a02.png
[b09322fadb894bc7819efbc4915b3433.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/413462ffc36745aa8bdf4ca56efdb620.png
[476bbebee9d242a19db46ca5ba1431a7.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/a5e38291bf4e4316a23e011e74349b85.png
[356636ea73264d65a402569d6052e680.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/df054e5deec3410bb98ff7c9cad67d7e.png
[59ac5f92b1fa47df8a8f78a0bd396e02.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/0c033b03dd6345a7bd05504e36ff4c11.png
[fb0421fb0bfa4dddaa1ba2f1f97910e2.png]: https://img-blog.csdnimg.cn/fb0421fb0bfa4dddaa1ba2f1f97910e2.png
[45114c8179d8420b94ea3ce3993019cb.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/0246efda1e1e42fba0845d8151757d9f.png
[0d1d43c686164b0b9e126d591d5f7f05.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/f0c18dd5f5374b5d993d5e4aab692d2e.png
[16a6f7aee71345ab822fd4784252dc51.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/c93ace66886e4be495a830360f6f7118.png
[38b2676e0e294e7e8ab83b9a6db2495c.png]: https://img-blog.csdnimg.cn/38b2676e0e294e7e8ab83b9a6db2495c.png
[e90c70de047f409b9472b50f18fc8408.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/a3f80fe5bc234a2bb319c5f6fadae102.png
[960eb835f48d4015abd1118b80f0206f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/c77467091ef04c3299d7d72b90437645.png
[5d1b4b35748746f9b942792493fae2a2.png]: https://img-blog.csdnimg.cn/5d1b4b35748746f9b942792493fae2a2.png
[30844bcfafa1447a944b43352efdc49b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/12/9214cc9e99054f67b52636d3a6239875.png