截图方式预览文件

　　用户需求：文件在上传后，需要在页面展示类似windows平铺视图，这时候我们把文件保存一份截图，在平铺视图上展示截图即可。

 

　　第一步：安装OpenOffice     当然服务器和本地根据平台不同下载不同版本

　　第二步：启动OpenOffice服务(windows范例)：

cd C:\Program Files (x86)\OpenOffice 4\programsoffice -headless -accept="socket,host=127.0.0.1,port=8100;urp;" -nofirststartwizardpause

　

　　转换工具类如下：

 

 

import java.awt.geom.AffineTransform;import java.awt.image.AffineTransformOp;import java.awt.image.BufferedImage;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.lang.reflect.Method;import java.security.AccessController;import java.security.PrivilegedAction;import java.util.Date;import java.util.Iterator;import javax.imageio.IIOImage;import javax.imageio.ImageIO;import javax.imageio.ImageWriter;import javax.imageio.stream.ImageOutputStream;import org.icepdf.core.pobjects.Document;import org.icepdf.core.pobjects.Page;import org.icepdf.core.util.GraphicsRenderingHints;import com.artofsolving.jodconverter.DocumentConverter;import com.artofsolving.jodconverter.openoffice.connection.OpenOfficeConnection;import com.artofsolving.jodconverter.openoffice.connection.SocketOpenOfficeConnection;import com.artofsolving.jodconverter.openoffice.converter.OpenOfficeDocumentConverter;@SuppressWarnings("all")public class FileConvertUtil {    private static final String[] OFFICE = new String[] { ".doc", ".docx", ".docx", ".ppt", ".pptx", ".xls", ".xlsx" };    private static final String[] IMG = new String[] { ".bmp", ".gif", ".jpg", ".tif", ".png" };    private static final String PDF = ".pdf";    private static final String TXT = ".txt";    public static final String FILETYPE_JPG = "jpg";    public static final String SUFF_IMAGE = "." + FILETYPE_JPG;        /**     * 根据源文件生成一个预览图片     *      * @param inputFilePath 文件路径     * @param suffix 文件后缀     * @return     * @throws Exception     */    public static int convert(String inputFilePath, String suffix) throws Exception {        int num = 0;        if (PDF.equals(suffix)) {            num = pdf2Jpg(inputFilePath);        }        if (TXT.equals(suffix)) {            num = txt2pdf(inputFilePath);        }        for (String sf : OFFICE) {            if (sf.equals(suffix)) {                num = Office2pdf(inputFilePath);                break;            }        }        for (String sf : IMG) {            if (sf.equals(suffix)) {                num = 1;                ImgConvert imgConvert = new ImgConvert();                imgConvert.convert(inputFilePath, "102x102", 102, 120);                imgConvert.convert(inputFilePath, "560x600", 560, 600);                break;            }        }        return num;    }    /**     * docx, .xls, .xlsx, .ppt, .pptx筿     *      * @param inputFilePath     */    public static int txt2pdf(String inputFilePath) {        int num = 0;        try {            OpenOfficeConnection connection = new SocketOpenOfficeConnection("127.0.0.1", 8100);            connection.connect();            DocumentConverter converter = new OpenOfficeDocumentConverter(connection);            String outputFilePath = getOutputFilePath(inputFilePath);            File inputFile = new File(inputFilePath);            inputFile = FileReName(inputFile, ".odt");            if (inputFile.exists()) {                File outputFile = new File(outputFilePath);                if (!outputFile.getParentFile().exists()) {                    outputFile.getParentFile().mkdirs();                }                converter.convert(inputFile, outputFile);            }            connection.disconnect();            num = pdf2Jpg(outputFilePath);        } catch (IOException e) {            e.printStackTrace();        }        return num;    }    public static File FileReName(File file, String suffix) {        String fileName = "/" + file.getName();        String target = file.getParent() + fileName.substring(0, fileName.lastIndexOf(".")) + suffix;        File file2 = new File(target);        file.renameTo(file2);        return file2;    }    /**     * docx, .xls, .xlsx, .ppt, .pptx筿     *      * @param inputFilePath     */    public static int Office2pdf(String inputFilePath) {        int num = 0;        try {            long l=new Date().getTime();                        OpenOfficeConnection connection = new SocketOpenOfficeConnection("127.0.0.1", 8100);            connection.connect();                        DocumentConverter converter = new OpenOfficeDocumentConverter(connection);                    String outputFilePath = getOutputFilePath(inputFilePath);            File inputFile = new File(inputFilePath);            if (inputFile.exists()) {                File outputFile = new File(outputFilePath);                if (!outputFile.getParentFile().exists()) {                    outputFile.getParentFile().mkdirs();                }                converter.convert(inputFile, outputFile);            }            connection.disconnect();            num = pdf2Jpg(outputFilePath);        } catch (IOException e) {            e.printStackTrace();        }        return num;    }    public static String getOutputFilePath(String inputFilePath) {        String outputFilePath = inputFilePath.substring(0, inputFilePath.lastIndexOf(".")) + ".pdf";        return outputFilePath;    }    /**     *      * 清空缓冲     *      * @param buffer     */    public static void unmap(final Object buffer) {        AccessController.doPrivileged(new PrivilegedAction() {            public Object run() {                try {                    Method getCleanerMethod = buffer.getClass().getMethod("cleaner", new Class[0]);                    getCleanerMethod.setAccessible(true);                    sun.misc.Cleaner cleaner = (sun.misc.Cleaner) getCleanerMethod.invoke(buffer, new Object[0]);                    cleaner.clean();                } catch (Exception e) {                    e.printStackTrace();                }                return null;            }        });    }        public static void  toThumbnail(String filePath){        BufferedImage bis = null;        try {            File fi = new File(filePath+".jpg"); //大图文件            File fo = new File(filePath+"102x102.jpg"); //将要转换出的小图文件            AffineTransform transform = new AffineTransform();            bis = ImageIO.read(fi);            int w = bis.getWidth();            int h = bis.getHeight();            double scale = (double)w/h;            int nw = 102;            int nh = (nw * h) / w;            if(nh>102) {                nh = 102;                nw = (nh * w) / h;            }            double sx = (double)nw / w;            double sy = (double)nh / h;            transform.setToScale(sx,sy);            AffineTransformOp ato = new AffineTransformOp(transform, null);            BufferedImage bid = new BufferedImage(nw, nh, BufferedImage.TYPE_3BYTE_BGR);            ato.filter(bis,bid);            ImageIO.write(bid, "jpg", fo);        } catch(Exception e) {            e.printStackTrace();        }        finally{                                }    }    /**     *      * @param inputFilePath     * @return     */    public static int pdf2Jpg(String inputFilePath) {         int maxPages =0;         try{            Document document = null;                 float rotation = 0f;            String imagepath = inputFilePath.replaceAll(".pdf", ".jpg");                 document = new Document();            document.setFile(inputFilePath);             maxPages = document.getPageTree().getNumberOfPages();            System.out.println(maxPages);                 BufferedImage img = (BufferedImage) document.getPageImage(0,                    GraphicsRenderingHints.SCREEN, Page.BOUNDARY_CROPBOX, rotation,1);                 Iterator iter = ImageIO.getImageWritersBySuffix(FILETYPE_JPG);            ImageWriter writer = (ImageWriter) iter.next();            File outFile = new File(imagepath);            FileOutputStream out = new FileOutputStream(outFile);            ImageOutputStream outImage = ImageIO.createImageOutputStream(out);            writer.setOutput(outImage);            writer.write(new IIOImage(img, null, null));                        toThumbnail(imagepath.substring(0,imagepath.lastIndexOf(".jpg")));                          } catch (Exception e) {             e.printStackTrace();        }        return maxPages;    }        public static void main(String[] args) {            pdf2Jpg("E:/111.pdf");    }}

　　

　　图片处理工具类：

import java.awt.image.BufferedImage;import java.io.File;import javax.imageio.ImageIO;public class ImgConvert {    private int width;    private int height;    private int scaleWidth;    double support = (double) 3.0;    double PI = (double) 3.14159265358978;    double[] contrib;    double[] normContrib;    double[] tmpContrib;    int startContrib, stopContrib;    int nDots;    int nHalfDots;    //fromFileStr原图片地坿,saveToFileStr生成缩略图地坿,formatWideth生成图片宽度,formatHeight高度    public void convert(String fromFileStr, String suffix, int formatWideth, int formatHeight) throws Exception {        BufferedImage srcImage;                int x = fromFileStr.lastIndexOf(".");        int l = fromFileStr.length();        String extName = fromFileStr.substring(x, l);        String filename = fromFileStr.substring(0, x);                File saveFile = new File(filename + suffix + extName);        File fromFile = new File(fromFileStr);        srcImage = javax.imageio.ImageIO.read(fromFile); // construct image        int imageWideth = srcImage.getWidth(null);        int imageHeight = srcImage.getHeight(null);        int changeToWideth = 0;        int changeToHeight = 0;        if (imageWideth > 0 && imageHeight > 0) {            if (imageWideth / imageHeight >= formatWideth / formatHeight) {                if (imageWideth > formatWideth) {                    changeToWideth = formatWideth;                    changeToHeight = (imageHeight * formatWideth) / imageWideth;                } else {                    changeToWideth = imageWideth;                    changeToHeight = imageHeight;                }            } else {                if (imageHeight > formatHeight) {                    changeToHeight = formatHeight;                    changeToWideth = (imageWideth * formatHeight) / imageHeight;                } else {                    changeToWideth = imageWideth;                    changeToHeight = imageHeight;                }            }        }        srcImage = imageZoomOut(srcImage, changeToWideth, changeToHeight);        ImageIO.write(srcImage, "JPEG", saveFile);    }    public BufferedImage imageZoomOut(BufferedImage srcBufferImage, int w, int h) {        width = srcBufferImage.getWidth();        height = srcBufferImage.getHeight();        scaleWidth = w;        if (DetermineResultSize(w, h) == 1) {            return srcBufferImage;        }        CalContrib();        BufferedImage pbOut = HorizontalFiltering(srcBufferImage, w);        BufferedImage pbFinalOut = VerticalFiltering(pbOut, h);        return pbFinalOut;    }    private int DetermineResultSize(int w, int h) {        double scaleH, scaleV;        scaleH = (double) w / (double) width;        scaleV = (double) h / (double) height;        if (scaleH >= 1.0 && scaleV >= 1.0) {            return 1;        }        return 0;    }    private double Lanczos(int i, int inWidth, int outWidth, double Support) {        double x;        x = (double) i * (double) outWidth / (double) inWidth;        return Math.sin(x * PI) / (x * PI) * Math.sin(x * PI / Support) / (x * PI / Support);    }    private void CalContrib() {        nHalfDots = (int) ((double) width * support / (double) scaleWidth);        nDots = nHalfDots * 2 + 1;        try {            contrib = new double[nDots];            normContrib = new double[nDots];            tmpContrib = new double[nDots];        } catch (Exception e) {            e.printStackTrace();            //System.out.println("init   contrib,normContrib,tmpContrib" + e);        }        int center = nHalfDots;        contrib[center] = 1.0;        double weight = 0.0;        int i = 0;        for (i = 1; i <= center; i++) {            contrib[center + i] = Lanczos(i, width, scaleWidth, support);            weight += contrib[center + i];        }        for (i = center - 1; i >= 0; i--) {            contrib[i] = contrib[center * 2 - i];        }        weight = weight * 2 + 1.0;        for (i = 0; i <= center; i++) {            normContrib[i] = contrib[i] / weight;        }        for (i = center + 1; i < nDots; i++) {            normContrib[i] = normContrib[center * 2 - i];        }    }    private void CalTempContrib(int start, int stop) {        double weight = 0;        int i = 0;        for (i = start; i <= stop; i++) {            weight += contrib[i];        }        for (i = start; i <= stop; i++) {            tmpContrib[i] = contrib[i] / weight;        }    }    private int GetRedValue(int rgbValue) {        int temp = rgbValue & 0x00ff0000;        return temp >> 16;    }    private int GetGreenValue(int rgbValue) {        int temp = rgbValue & 0x0000ff00;        return temp >> 8;    }    private int GetBlueValue(int rgbValue) {        return rgbValue & 0x000000ff;    }    private int ComRGB(int redValue, int greenValue, int blueValue) {        return (redValue << 16) + (greenValue << 8) + blueValue;    }    private int HorizontalFilter(BufferedImage bufImg, int startX, int stopX, int start, int stop, int y, double[] pContrib) {        double valueRed = 0.0;        double valueGreen = 0.0;        double valueBlue = 0.0;        int valueRGB = 0;        int i, j;        for (i = startX, j = start; i <= stopX; i++, j++) {            valueRGB = bufImg.getRGB(i, y);            valueRed += GetRedValue(valueRGB) * pContrib[j];            valueGreen += GetGreenValue(valueRGB) * pContrib[j];            valueBlue += GetBlueValue(valueRGB) * pContrib[j];        }        valueRGB = ComRGB(Clip((int) valueRed), Clip((int) valueGreen), Clip((int) valueBlue));        return valueRGB;    }    private BufferedImage HorizontalFiltering(BufferedImage bufImage, int iOutW) {        int dwInW = bufImage.getWidth();        int dwInH = bufImage.getHeight();        int value = 0;        BufferedImage pbOut = new BufferedImage(iOutW, dwInH, BufferedImage.TYPE_INT_RGB);        for (int x = 0; x < iOutW; x++) {            int startX;            int start;            int X = (int) (((double) x) * ((double) dwInW) / ((double) iOutW) + 0.5);            int y = 0;            startX = X - nHalfDots;            if (startX < 0) {                startX = 0;                start = nHalfDots - X;            } else {                start = 0;            }            int stop;            int stopX = X + nHalfDots;            if (stopX > (dwInW - 1)) {                stopX = dwInW - 1;                stop = nHalfDots + (dwInW - 1 - X);            } else {                stop = nHalfDots * 2;            }            if (start > 0 || stop < nDots - 1) {                CalTempContrib(start, stop);                for (y = 0; y < dwInH; y++) {                    value = HorizontalFilter(bufImage, startX, stopX, start, stop, y, tmpContrib);                    pbOut.setRGB(x, y, value);                }            } else {                for (y = 0; y < dwInH; y++) {                    value = HorizontalFilter(bufImage, startX, stopX, start, stop, y, normContrib);                    pbOut.setRGB(x, y, value);                }            }        }        return pbOut;    }    private int VerticalFilter(BufferedImage pbInImage, int startY, int stopY, int start, int stop, int x, double[] pContrib) {        double valueRed = 0.0;        double valueGreen = 0.0;        double valueBlue = 0.0;        int valueRGB = 0;        int i, j;        for (i = startY, j = start; i <= stopY; i++, j++) {            valueRGB = pbInImage.getRGB(x, i);            valueRed += GetRedValue(valueRGB) * pContrib[j];            valueGreen += GetGreenValue(valueRGB) * pContrib[j];            valueBlue += GetBlueValue(valueRGB) * pContrib[j];        }        valueRGB = ComRGB(Clip((int) valueRed), Clip((int) valueGreen), Clip((int) valueBlue));        return valueRGB;    }    private BufferedImage VerticalFiltering(BufferedImage pbImage, int iOutH) {        int iW = pbImage.getWidth();        int iH = pbImage.getHeight();        int value = 0;        BufferedImage pbOut = new BufferedImage(iW, iOutH, BufferedImage.TYPE_INT_RGB);        for (int y = 0; y < iOutH; y++) {            int startY;            int start;            int Y = (int) (((double) y) * ((double) iH) / ((double) iOutH) + 0.5);            startY = Y - nHalfDots;            if (startY < 0) {                startY = 0;                start = nHalfDots - Y;            } else {                start = 0;            }            int stop;            int stopY = Y + nHalfDots;            if (stopY > (int) (iH - 1)) {                stopY = iH - 1;                stop = nHalfDots + (iH - 1 - Y);            } else {                stop = nHalfDots * 2;            }            if (start > 0 || stop < nDots - 1) {                CalTempContrib(start, stop);                for (int x = 0; x < iW; x++) {                    value = VerticalFilter(pbImage, startY, stopY, start, stop, x, tmpContrib);                    pbOut.setRGB(x, y, value);                }            } else {                for (int x = 0; x < iW; x++) {                    value = VerticalFilter(pbImage, startY, stopY, start, stop, x, normContrib);                    pbOut.setRGB(x, y, value);                }            }        }        return pbOut;    }    int Clip(int x) {        if (x < 0)            return 0;        if (x > 255)            return 255;        return x;    }}