org.mvel2.templates.util.TemplateTools Maven / Gradle / Ivy

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/**
 * MVEL 2.0
 * Copyright (C) 2007 The Codehaus
 * Mike Brock, Dhanji Prasanna, John Graham, Mark Proctor
 *
 * Licensed 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.mvel2.templates.util;

import static java.nio.ByteBuffer.allocateDirect;
import static org.mvel2.util.ParseTools.balancedCapture;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

import org.mvel2.templates.TemplateError;
import org.mvel2.templates.res.Node;
import org.mvel2.templates.res.TerminalNode;

public class TemplateTools {

    public static Node getLastNode(Node node) {
        Node n = node;
        while (true) {
            if (n.getNext() instanceof TerminalNode) return n;
            n = n.getNext();
        }
    }

    public static int captureToEOS(char[] expression, int cursor) {
        int length = expression.length;
        while (cursor != length) {
            switch (expression[cursor]) {
                case '(':
                case '[':
                case '{':
                    cursor = balancedCapture(expression, cursor, expression[cursor]);
                    break;

                case ';':
                case '}':
                    return cursor;

            }
            cursor++;
        }

        return cursor;
    }

    public static String readInFile(String file) {
        return readInFile(new File(file));
    }

    public static String readInFile(File file) {
        try {
            FileChannel fc = new FileInputStream(file).getChannel();
            ByteBuffer buf = allocateDirect(10);
            StringBuilder appender = new StringBuilder();
            int read;

            while (true) {
                buf.rewind();
                if ((read = fc.read(buf)) != -1) {
                    buf.rewind();
                    for (; read != 0; read--) {
                        appender.append((char) buf.get());
                    }
                } else {
                    break;
                }
            }

            fc.close();

            return appender.toString();
        } catch (FileNotFoundException e) {
            throw new TemplateError("cannot include template '" + file.getName() + "': file not found.");
        } catch (IOException e) {
            throw new TemplateError("unknown I/O exception while including '" + file.getName() + "' (stacktrace nested)", e);
        }
    }

    public static String readStream(InputStream instream) {
        try {
            byte[] buf = new byte[10];
            StringBuilder appender = new StringBuilder();
            int read;
            while ((read = instream.read(buf)) != -1) {
                for (int i = 0; i < read; i++) {
                    appender.append((char) buf[i]);
                }
            }

            return appender.toString();
        } catch (NullPointerException e) {
            if (instream == null) {
                throw new TemplateError("null input stream", e);
            } else {
                throw e;
            }
        } catch (IOException e) {
            throw new TemplateError("unknown I/O exception while including (stacktrace nested)", e);
        }
    }
}