截图方式预览文件

 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   http://www.openoffice.org/download/  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\program
soffice -headless -accept="socket,host=127.0.0.1,port=8100;urp;" -nofirststartwizard
pause

　

　　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;
    }

}