java web通过openoffice实现文档网页预览（类似百度文库）

package cn.com.mvc.util;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;

public class ChangeFileCode {

    // 读取的文件

    private String fileIn;

    // 读取時文件用的编码

    private String fileInEn;

    // 写出的文件

    private String fileOut;

    // 写出時文件用的编码

    private String fileOutEn;

    /**
     * 
     * 获取源文件的编码
     * 
     * @param filePath
     *            源文件所在的绝对路径
     * 
     * @return
     * 
     */

    public String getFileEnCode(String filePath) {

        InputStream inputStream = null;

        String code = "";

        try {

            inputStream = new FileInputStream(filePath);

            byte[] head = new byte[3];

            inputStream.read(head);

            code = "gb2312";

            if (head[0] == -1 && head[1] == -2)

                code = "UTF-16";

            if (head[0] == -2 && head[1] == -1)

                code = "Unicode";

            if (head[0] == -17 && head[1] == -69 && head[2] == -65)

                code = "UTF-8";

            System.out.println(code);

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            try {

                inputStream.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

        return code;

    }

    public void setFileIn(String fileInPath, String fileInEncoding) {

        this.setFileIn(fileInPath);

        this.setFileInEn(fileInEncoding);

    }

    public void setFileOut(String fileOutPath, String fileOutEncoding) {

        this.setFileOut(fileOutPath);

        this.setFileOutEn(fileOutEncoding);

    }

    public void start() {

        String str = this.read(fileIn, fileInEn);

        this.write(fileOut, fileOutEn, str);

    }

    /**
     * 
     * 读文件
     *
     * 
     * 
     * @param fileName
     * 
     * @param encoding
     * 
     */

    private String read(String fileName, String encoding) {

        try {

            BufferedReader in = new BufferedReader(new InputStreamReader(

                    new FileInputStream(fileName), encoding));

            String string = "";

            String str = "";

            while ((str = in.readLine()) != null) {

                string += str + "\n";

            }

            in.close();

            return string;

        } catch (Exception ex) {

            ex.printStackTrace();

        }

        return "";

    }

    /**
     * 
     * 写文件
     *
     * 
     * 
     * @param fileName
     * 
     *            新的文件名
     * 
     * @param encoding
     * 
     *            写出的文件的编码方式
     * 
     * @param str
     * 
     */

    private void write(String fileName, String encoding, String str) {

        try {

            Writer out = new BufferedWriter(new OutputStreamWriter(

                    new FileOutputStream(fileName), encoding));

            out.write(str);

            out.close();

        } catch (Exception ex) {

            ex.printStackTrace();

        }

    }

    public String getFileIn() {

        return fileIn;

    }

    public void setFileIn(String fileIn) {

        this.fileIn = fileIn;

    }

    public String getFileInEn() {

        return fileInEn;

    }

    public void setFileInEn(String fileInEn) {

        this.fileInEn = fileInEn;

    }

    public String getFileOut() {

        return fileOut;

    }

    public void setFileOut(String fileOut) {

        this.fileOut = fileOut;

    }

    public String getFileOutEn() {

        return fileOutEn;

    }

    public void setFileOutEn(String fileOutEn) {

        this.fileOutEn = fileOutEn;

    }
}