blobfilevalue.java

来自「jsr170接口的java实现。是个apache的开源项目。」· Java 代码 · 共 549 行 · 第 1/2 页

     * calling this method will have no effect.
     *
     * @see #delete()
     * @see #delete(boolean)
     */
    public void discard() {
        if (!temp) {
            // do nothing if this instance is not backed by temporarily
            // allocated resource/buffer
            return;
        }
        if (file != null) {
            // this instance is backed by a temp file
            file.delete();
        } else if (buffer != null) {
            // this instance is backed by an in-memory buffer
            buffer = EMPTY_BYTE_ARRAY;
        }
    }

    /**
     * Deletes the persistent resource backing this <code>BLOBFileValue</code>.
     * Same as <code>{@link #delete(false)}</code>.
     * <p/>
     * If this <code>BLOBFileValue</code> is <i>not</i> backed by a persistent
     * resource calling this method will have no effect.
     *
     * @see #discard()
     */
    public void delete() {
        if (!temp) {
            delete(false);
        }
    }

    /**
     * Deletes the persistent resource backing this <code>BLOBFileValue</code>.
     *
     * @param pruneEmptyParentDirs if <code>true</code>, empty parent directories
     *                             will automatically be deleted
     */
    public void delete(boolean pruneEmptyParentDirs) {
        if (file != null) {
            // this instance is backed by a 'real' file
            file.delete();
            if (pruneEmptyParentDirs) {
                // prune empty parent directories
                File parent = file.getParentFile();
                while (parent != null && parent.delete()) {
                    parent = parent.getParentFile();
                }
            }
        } else if (fsResource != null) {
            // this instance is backed by a resource in the virtual file system
            try {
                fsResource.delete(pruneEmptyParentDirs);
            } catch (FileSystemException fse) {
                // ignore
                log.warn("Error while deleting BLOBFileValue: " + fse.getMessage());
            }
        } else {
            // this instance is backed by an in-memory buffer
            buffer = EMPTY_BYTE_ARRAY;
        }
    }

    /**
     * Spools the contents of this <code>BLOBFileValue</code> to the given
     * output stream.
     *
     * @param out output stream
     * @throws RepositoryException if the input stream for this
     *                             <code>BLOBFileValue</code> could not be obtained
     * @throws IOException         if an error occurs while while spooling
     */
    public void spool(OutputStream out) throws RepositoryException, IOException {
        InputStream in;
        if (file != null) {
            // this instance is backed by a 'real' file
            try {
                in = new FileInputStream(file);
            } catch (FileNotFoundException fnfe) {
                throw new RepositoryException("file backing binary value not found",
                        fnfe);
            }
        } else if (fsResource != null) {
            // this instance is backed by a resource in the virtual file system
            try {
                in = fsResource.getInputStream();
            } catch (FileSystemException fse) {
                throw new RepositoryException(fsResource.getPath()
                        + ": the specified resource does not exist", fse);
            }
        } else {
            // this instance is backed by an in-memory buffer
            in = new ByteArrayInputStream(buffer);
        }
        try {
            byte[] buffer = new byte[0x2000];
            int read;
            while ((read = in.read(buffer)) > 0) {
                out.write(buffer, 0, read);
            }
        } finally {
            try {
                in.close();
            } catch (IOException ignore) {
            }
        }
    }

    //-------------------------------------------< java.lang.Object overrides >
    /**
     * Returns a string representation of this <code>BLOBFileValue</code>
     * instance. The string representation of a resource backed value is
     * the path of the underlying resource. If this instance is backed by an
     * in-memory buffer the generic object string representation of the byte
     * array will be used instead.
     *
     * @return A string representation of this <code>BLOBFileValue</code> instance.
     */
    public String toString() {
        if (file != null) {
            // this instance is backed by a 'real' file
            return file.toString();
        } else if (fsResource != null) {
            // this instance is backed by a resource in the virtual file system
            return fsResource.toString();
        } else {
            // this instance is backed by an in-memory buffer
            return buffer.toString();
        }
    }

    /**
     * {@inheritDoc}
     */
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof BLOBFileValue) {
            BLOBFileValue other = (BLOBFileValue) obj;
            return ((file == null ? other.file == null : file.equals(other.file))
                    && (fsResource == null ? other.fsResource == null : fsResource.equals(other.fsResource))
                    && Arrays.equals(buffer, other.buffer));
        }
        return false;
    }

    /**
     * Returns zero to satisfy the Object equals/hashCode contract.
     * This class is mutable and not meant to be used as a hash key.
     *
     * @return always zero
     * @see Object#hashCode()
     */
    public int hashCode() {
        return 0;
    }

    //----------------------------------------------------------------< Value >
    /**
     * {@inheritDoc}
     */
    public int getType() {
        return TYPE;
    }

    /**
     * {@inheritDoc}
     */
    public String getString()
            throws ValueFormatException, IllegalStateException,
            RepositoryException {
        if (text == null) {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            try {
                spool(out);
                byte[] data = out.toByteArray();
                text = new String(data, DEFAULT_ENCODING);
            } catch (UnsupportedEncodingException e) {
                throw new RepositoryException(DEFAULT_ENCODING
                        + " not supported on this platform", e);
            } catch (IOException e) {
                throw new ValueFormatException("conversion from stream to string failed", e);
            } finally {
                try {
                    out.close();
                } catch (IOException e) {
                    // ignore
                }
            }
        }
        return text;
    }

    /**
     * {@inheritDoc}
     */
    public InputStream getStream()
            throws IllegalStateException, RepositoryException {
        // always return a 'fresh' stream
        if (file != null) {
            // this instance is backed by a 'real' file
            try {
                return new FileInputStream(file);
            } catch (FileNotFoundException fnfe) {
                throw new RepositoryException("file backing binary value not found",
                        fnfe);
            }
        } else if (fsResource != null) {
            // this instance is backed by a resource in the virtual file system
            try {
                return fsResource.getInputStream();
            } catch (FileSystemException fse) {
                throw new RepositoryException(fsResource.getPath()
                        + ": the specified resource does not exist", fse);
            }
        } else {
            return new ByteArrayInputStream(buffer);
        }
    }

    /**
     * {@inheritDoc}
     */
    public double getDouble()
            throws ValueFormatException, IllegalStateException,
            RepositoryException {
        try {
            return Double.parseDouble(getString());
        } catch (NumberFormatException e) {
            throw new ValueFormatException("conversion to double failed", e);
        }
    }

    /**
     * {@inheritDoc}
     */
    public Calendar getDate()
            throws ValueFormatException, IllegalStateException,
            RepositoryException {
        Calendar cal = ISO8601.parse(getString());
        if (cal != null) {
            return cal;
        } else {
            throw new ValueFormatException("not a valid date format");
        }
    }

    /**
     * {@inheritDoc}
     */
    public long getLong()
            throws ValueFormatException, IllegalStateException,
            RepositoryException {
        try {
            return Long.parseLong(getString());
        } catch (NumberFormatException e) {
            throw new ValueFormatException("conversion to long failed", e);
        }
    }

    /**
     * {@inheritDoc}
     */
    public boolean getBoolean()
            throws ValueFormatException, IllegalStateException,
            RepositoryException {
        return Boolean.valueOf(getString()).booleanValue();
    }
}