org.apache.pdfbox.pdfwriter.ContentStreamWriter.java Source code

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Here is the source code for org.apache.pdfbox.pdfwriter.ContentStreamWriter.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.pdfbox.pdfwriter;

import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;
import org.apache.pdfbox.contentstream.operator.Operator;
import org.apache.pdfbox.contentstream.operator.OperatorName;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSBoolean;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSFloat;
import org.apache.pdfbox.cos.COSInteger;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSString;

/**
 * A class that will take a list of tokens and write out a stream with them.
 *
 * @author Ben Litchfield
 */
public class ContentStreamWriter {
    private final OutputStream output;
    /**
     * space character.
     */
    public static final byte[] SPACE = new byte[] { 32 };

    /**
     * standard line separator
     */
    public static final byte[] EOL = new byte[] { 0x0A };

    /**
     * This will create a new content stream writer.
     *
     * @param out The stream to write the data to.
     */
    public ContentStreamWriter(OutputStream out) {
        output = out;
    }

    /**
     * Writes a single operand token.
     *
     * @param base The operand to write to the stream.
     * @throws IOException If there is an error writing to the stream.
     */
    public void writeToken(COSBase base) throws IOException {
        writeObject(base);
    }

    /**
     *  Writes a single operator token.
     *
     * @param op The operator to write to the stream.
     * @throws IOException If there is an error writing to the stream.
     */
    public void writeToken(Operator op) throws IOException {
        writeObject(op);
    }

    /**
     * Writes a series of tokens followed by a new line.
     * 
     * @param tokens The tokens to write to the stream.
     * @throws IOException If there is an error writing to the stream.
     */
    public void writeTokens(Object... tokens) throws IOException {
        for (Object token : tokens) {
            writeObject(token);
        }
        output.write("\n".getBytes(StandardCharsets.US_ASCII));
    }

    /**
     * This will write out the list of tokens to the stream.
     *
     * @param tokens The tokens to write to the stream.
     * @throws IOException If there is an error writing to the stream.
     */
    public void writeTokens(List<?> tokens) throws IOException {
        for (Object token : tokens) {
            writeObject(token);
        }
    }

    private void writeObject(Object o) throws IOException {
        if (o instanceof COSString) {
            COSWriter.writeString((COSString) o, output);
            output.write(SPACE);
        } else if (o instanceof COSFloat) {
            ((COSFloat) o).writePDF(output);
            output.write(SPACE);
        } else if (o instanceof COSInteger) {
            ((COSInteger) o).writePDF(output);
            output.write(SPACE);
        } else if (o instanceof COSBoolean) {
            ((COSBoolean) o).writePDF(output);
            output.write(SPACE);
        } else if (o instanceof COSName) {
            ((COSName) o).writePDF(output);
            output.write(SPACE);
        } else if (o instanceof COSArray) {
            COSArray array = (COSArray) o;
            output.write(COSWriter.ARRAY_OPEN);
            for (int i = 0; i < array.size(); i++) {
                writeObject(array.get(i));
                output.write(SPACE);
            }

            output.write(COSWriter.ARRAY_CLOSE);
        } else if (o instanceof COSDictionary) {
            COSDictionary obj = (COSDictionary) o;
            output.write(COSWriter.DICT_OPEN);
            for (Map.Entry<COSName, COSBase> entry : obj.entrySet()) {
                if (entry.getValue() != null) {
                    writeObject(entry.getKey());
                    output.write(SPACE);
                    writeObject(entry.getValue());
                    output.write(SPACE);
                }
            }
            output.write(COSWriter.DICT_CLOSE);
            output.write(SPACE);
        } else if (o instanceof Operator) {
            Operator op = (Operator) o;
            if (op.getName().equals(OperatorName.BEGIN_INLINE_IMAGE)) {
                output.write(OperatorName.BEGIN_INLINE_IMAGE.getBytes(StandardCharsets.ISO_8859_1));
                COSDictionary dic = op.getImageParameters();
                for (COSName key : dic.keySet()) {
                    Object value = dic.getDictionaryObject(key);
                    key.writePDF(output);
                    output.write(SPACE);
                    writeObject(value);
                    output.write(EOL);
                }
                output.write(OperatorName.BEGIN_INLINE_IMAGE_DATA.getBytes(StandardCharsets.ISO_8859_1));
                output.write(EOL);
                output.write(op.getImageData());
                output.write(EOL);
                output.write(OperatorName.END_INLINE_IMAGE.getBytes(StandardCharsets.ISO_8859_1));
                output.write(EOL);
            } else {
                output.write(op.getName().getBytes(StandardCharsets.ISO_8859_1));
                output.write(EOL);
            }
        } else {
            throw new IOException("Error:Unknown type in content stream:" + o);
        }
    }
}