com.wiris.plugin.storage.FileStorageAndCache Maven / Gradle / Ivy

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package com.wiris.plugin.storage;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;

import java.util.Properties;

import javax.servlet.http.HttpServletRequest;

import com.wiris.plugin.LibWIRIS;

/**
 * This class uses the md5 as a digest method and the "cache" folder to store the
 * association of the digest with the formula source (MathML).
 * The images of the formulas are also stored in the "formula" folder.
 * Both the "cache" and "formula" folders are obtained from the WIRIS plugin
 * configuration.
 */
public class FileStorageAndCache implements StorageAndCache {
    String formulaDirectory;
    String cacheDirectory;

    public FileStorageAndCache() {
    }

    public String codeDigest(String content) {
        try {
            String digest = LibWIRIS.md5(content.getBytes("UTF-8"));
            FileOutputStream fileOutputStream = new FileOutputStream(new File(this.formulaDirectory + "/" + digest + ".ini"));
            fileOutputStream.write(content.getBytes("UTF-8"));
            fileOutputStream.flush();
            fileOutputStream.close();
            return digest;
        } catch (Exception e) {
            throw new Error(e);
        }
    }

    public String decodeDigest(String digest) {
        digest = FileStorageAndCache.sanitizeDigest(digest);
        String[] digestInformation = this.getDigestInformation(digest);

        try {
            File file = new File(this.formulaDirectory + "/" + digestInformation[0] + ".ini");
            FileInputStream inputStream = new FileInputStream(file);
            ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
            LibWIRIS.flow(inputStream, dataStream);
            String content = dataStream.toString();

            if (digestInformation[1] != null) {
                content += "\r\nformat=" + digestInformation[1];
            }

            return content;
        } catch (FileNotFoundException e) {
            return null;
        } catch (Exception e) {
            throw new Error(e);
        }
    }

    public String[] getDigestInformation(String digest) {
        String extension = null;
        int dotPosition = digest.lastIndexOf(".");

        if (dotPosition != -1) {
            extension = digest.substring(dotPosition + 1, digest.length());

            if (!extension.equals("png") && !extension.equals("swf")) {
                extension = null;
            } else {
                digest = digest.substring(0, dotPosition);
            }
        }

        return new String[] { digest, extension };
    }

    public void init(HttpServletRequest request, Properties config) {
        this.cacheDirectory = config.getProperty("wiriscachedirectory");

        if (this.cacheDirectory == null) {
            throw new Error("wiriscachedirectory property is not defined in configuration.ini");
        }

        this.formulaDirectory = config.getProperty("wirisformuladirectory");

        if (this.formulaDirectory == null) {
            throw new Error("wirisformuladirectory property is not defined in configuration.ini");
        }
    }

    public byte[] retreiveData(String digest) {
        digest = FileStorageAndCache.sanitizeDigest(digest);
        String[] digestInformation = this.getDigestInformation(digest);

        if (digestInformation[1] == null) {
            digestInformation[1] = "png";
        }

        try {
            File file = new File(this.cacheDirectory + "/" + digestInformation[0] + "." + digestInformation[1]);
            FileInputStream inputStream = new FileInputStream(file);
            ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
            LibWIRIS.flow(inputStream, dataStream);
            return dataStream.toByteArray();
        } catch (FileNotFoundException e) {
            return null;
        } catch (Exception e) {
            throw new Error(e);
        }
    }

    private static String sanitizeDigest(String digest) {
        return (new File(digest)).getName();
    }

    public void storeData(String digest, byte[] stream) {
        digest = FileStorageAndCache.sanitizeDigest(digest);
        String[] digestInformation = this.getDigestInformation(digest);

        if (digestInformation[1] == null) {
            digestInformation[1] = "png";
        }

        try {
            BufferedOutputStream fileOutput = 
                new BufferedOutputStream(new FileOutputStream(new File(this.cacheDirectory + "/" + digestInformation[0] + 
                                                                       "." + digestInformation[1])));
            fileOutput.write(stream);
            fileOutput.flush();
            fileOutput.close();
        } catch (Exception e) {
            throw new Error(e);
        }
    }
}