【Java】WIN解析exe文件

该ExeUtil的主要功能是文件头部获取exe的版本号。

import com.google.common.base.Throwables;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.RandomAccessFile;

/**
 * exe版本号解析
 *
 * @Author wucl
 * @Date 2017/11/28
 */
public class ExeUtil {

    private static final Logger LOGGER = LoggerFactory.getLogger(ExeUtil.class);

    public static String getVersion(File file) {
        byte[] buffer;
        String str;
        RandomAccessFile raf = null;
        try {
            raf = new RandomAccessFile(file, "r");
            buffer = new byte[64];
            raf.read(buffer);
            str = "" + (char) buffer[0] + (char) buffer[1];
            if (!"MZ".equals(str)) {
                return null;
            }

            int peOffset = unpack(new byte[]{buffer[60], buffer[61], buffer[62], buffer[63]});
            if (peOffset < 64) {
                return null;
            }

            raf.seek(peOffset);
            buffer = new byte[24];
            raf.read(buffer);
            str = "" + (char) buffer[0] + (char) buffer[1];
            if (!"PE".equals(str)) {
                return null;
            }
            int machine = unpack(new byte[]{buffer[4], buffer[5]});
            if (machine != 332) {
                return null;
            }

            int noSections = unpack(new byte[]{buffer[6], buffer[7]});
            int optHdrSize = unpack(new byte[]{buffer[20], buffer[21]});
            raf.seek(raf.getFilePointer() + optHdrSize);
            boolean resFound = false;
            for (int i = 0; i < noSections; i++) {
                buffer = new byte[40];
                raf.read(buffer);
                str = "" + (char) buffer[0] + (char) buffer[1] +
                        (char) buffer[2] + (char) buffer[3] + (char) buffer[4];
                if (".rsrc".equals(str)) {
                    resFound = true;
                    break;
                }
            }
            if (!resFound) {
                return null;
            }

            int infoVirt = unpack(new byte[]{buffer[12], buffer[13], buffer[14], buffer[15]});
            int infoSize = unpack(new byte[]{buffer[16], buffer[17], buffer[18], buffer[19]});
            int infoOff = unpack(new byte[]{buffer[20], buffer[21], buffer[22], buffer[23]});
            raf.seek(infoOff);
            buffer = new byte[infoSize];
            raf.read(buffer);
            int numDirs = unpack(new byte[]{buffer[14], buffer[15]});
            boolean infoFound = false;
            int subOff = 0;
            for (int i = 0; i < numDirs; i++) {
                int type = unpack(new byte[]{buffer[i * 8 + 16], buffer[i * 8 + 17], buffer[i * 8 + 18], buffer[i * 8 + 19]});
                if (type == 16) {                          //FILEINFO resource
                    infoFound = true;
                    subOff = unpack(new byte[]{buffer[i * 8 + 20], buffer[i * 8 + 21], buffer[i * 8 + 22], buffer[i * 8 + 23]});
                    break;
                }
            }
            if (!infoFound) {
                return null;
            }

            subOff = subOff & 0x7fffffff;
            infoOff = unpack(new byte[]{buffer[subOff + 20], buffer[subOff + 21], buffer[subOff + 22], buffer[subOff + 23]}); //offset of first FILEINFO
            infoOff = infoOff & 0x7fffffff;
            infoOff = unpack(new byte[]{buffer[infoOff + 20], buffer[infoOff + 21], buffer[infoOff + 22], buffer[infoOff + 23]});    //offset to data
            int dataOff = unpack(new byte[]{buffer[infoOff], buffer[infoOff + 1], buffer[infoOff + 2], buffer[infoOff + 3]});
            dataOff = dataOff - infoVirt;

            int version1 = unpack(new byte[]{buffer[dataOff + 48], buffer[dataOff + 48 + 1]});
            int version2 = unpack(new byte[]{buffer[dataOff + 48 + 2], buffer[dataOff + 48 + 3]});
            int version3 = unpack(new byte[]{buffer[dataOff + 48 + 4], buffer[dataOff + 48 + 5]});
            int version4 = unpack(new byte[]{buffer[dataOff + 48 + 6], buffer[dataOff + 48 + 7]});
            return version2 + "." + version1 + "." + version4 + "." + version3;
        } catch (Exception e) {
            LOGGER.error("文件{}版本号解析失败！错误信息：{}", file.getAbsolutePath(), Throwables.getStackTraceAsString(e));
            return null;
        } finally {
            if (raf != null) {
                try {
                    raf.close();
                } catch (Exception e) {
                    LOGGER.error("关闭随机访问文件失败！", e);
                }
            }
        }
    }

    public static int unpack(byte[] b) {
        int num = 0;
        for (int i = 0; i < b.length; i++) {
            num = 256 * num + (b[b.length - 1 - i] & 0xff);
        }
        return num;
    }
}