com.whaleal.icefrog.extra.compress.extractor.StreamExtractor Maven / Gradle / Ivy

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icefrog 扩展工具类（提供其它类库的封装）
There is a newer version: 1.1.71
package com.whaleal.icefrog.extra.compress.extractor;

import com.whaleal.icefrog.core.io.FileUtil;
import com.whaleal.icefrog.core.io.IORuntimeException;
import com.whaleal.icefrog.core.io.IoUtil;
import com.whaleal.icefrog.core.lang.Filter;
import com.whaleal.icefrog.core.lang.Precondition;
import com.whaleal.icefrog.core.util.StrUtil;
import com.whaleal.icefrog.extra.compress.CompressException;
import org.apache.commons.compress.archivers.ArchiveEntry;
import org.apache.commons.compress.archivers.ArchiveException;
import org.apache.commons.compress.archivers.ArchiveInputStream;
import org.apache.commons.compress.archivers.ArchiveStreamFactory;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;

/**
 * 数据解压器，即将归档打包的数据释放
 *
 * @author looly
 */
public class StreamExtractor implements Extractor {

    private final ArchiveInputStream in;

    /**
     * 构造
     *
     * @param charset 编码
     * @param file    包文件
     */
    public StreamExtractor( Charset charset, File file ) {
        this(charset, null, file);
    }

    /**
     * 构造
     *
     * @param charset      编码
     * @param archiverName 归档包格式，null表示自动检测
     * @param file         包文件
     */
    public StreamExtractor( Charset charset, String archiverName, File file ) {
        this(charset, archiverName, FileUtil.getInputStream(file));
    }

    /**
     * 构造
     *
     * @param charset 编码
     * @param in      包流
     */
    public StreamExtractor( Charset charset, InputStream in ) {
        this(charset, null, in);
    }

    /**
     * 构造
     *
     * @param charset      编码
     * @param archiverName 归档包格式，null表示自动检测
     * @param in           包流
     */
    public StreamExtractor( Charset charset, String archiverName, InputStream in ) {
        final ArchiveStreamFactory factory = new ArchiveStreamFactory(charset.name());
        try {
            in = IoUtil.toBuffered(in);
            if (StrUtil.isBlank(archiverName)) {
                this.in = factory.createArchiveInputStream(in);
            } else {
                this.in = factory.createArchiveInputStream(archiverName, in);
            }
        } catch (ArchiveException e) {
            throw new CompressException(e);
        }
    }

    /**
     * 释放（解压）到指定目录，结束后自动关闭流，此方法只能调用一次
     *
     * @param targetDir 目标目录
     * @param filter    解压文件过滤器，用于指定需要释放的文件，null表示不过滤。当{@link Filter#accept(Object)}为true时释放。
     */
    @Override
    public void extract( File targetDir, Filter filter ) {
        try {
            extractInternal(targetDir, filter);
        } catch (IOException e) {
            throw new IORuntimeException(e);
        } finally {
            close();
        }
    }

    /**
     * 释放（解压）到指定目录
     *
     * @param targetDir 目标目录
     * @param filter    解压文件过滤器，用于指定需要释放的文件，null表示不过滤。当{@link Filter#accept(Object)}为true时释放。
     * @throws IOException IO异常
     */
    private void extractInternal( File targetDir, Filter filter ) throws IOException {
        Precondition.isTrue(null != targetDir && ((false == targetDir.exists()) || targetDir.isDirectory()), "target must be dir.");
        final ArchiveInputStream in = this.in;
        ArchiveEntry entry;
        File outItemFile;
        while (null != (entry = in.getNextEntry())) {
            if (null != filter && false == filter.accept(entry)) {
                continue;
            }
            if (false == in.canReadEntryData(entry)) {
                // 无法读取的文件直接跳过
                continue;
            }
            outItemFile = FileUtil.file(targetDir, entry.getName());
            if (entry.isDirectory()) {
                // 创建对应目录
                //noinspection ResultOfMethodCallIgnored
                outItemFile.mkdirs();
            } else {
                FileUtil.writeFromStream(in, outItemFile, false);
            }
        }
    }

    @Override
    public void close() {
        IoUtil.close(this.in);
    }
}