Java解压缩rar文件_com.github.junrar.exception.unsupportedrarv5except

之前工作中遇到一个需求：rar 文件的压缩与解压缩。但是因为需求变动，还没来得及写，最近得空调研一下，发现 rar 比 zip 处理麻烦很多，这里小小记录一下。

rar是个专有格式，rar许可证不允许软件开发工具如JDK集成它，如果要在Java中解压rar文件，只能利用第三方工具依赖，如 junrar。官方地址为：GitHub - junrar/junrar: Plain Java unrar library

但是经过调研，发现压缩文件为 rar 还是很困难，没找到便捷可用的方法，这里仅记录 rar 文件解压的坑

 1. Maven 依赖

<dependency>
    <groupId>com.github.junrar</groupId>
    <artifactId>junrar</artifactId>
    <version>7.5.5</version>
</dependency>

2. 代码实现

import com.github.junrar.Junrar;
import com.github.junrar.exception.RarException;
 
import java.io.File;
import java.io.IOException;
 
public class CompressTest {
 
    public static void main(String[] args) {
        rar();
    }
 
    private static void rar() {
        try {
            File rar = new File("D:/test/diff.rar");
            File destinationFolder = new File("D:/test/rar");
            Junrar.extract(rar, destinationFolder);
        } catch (IOException e) {
            throw new RuntimeException(e);
        } catch (RarException e) {
            throw new RuntimeException(e);
        }
    }
 
}

3. 测试与问题

我使用 winrar 创建了一个压缩文件 diff.rar，然后运行代码，抛出以下错误：

17:16:52.273 [main] WARN com.github.junrar.Archive - Support for rar version 5 is not yet implemented!
17:16:52.276 [main] WARN com.github.junrar.Archive - exception in archive constructor maybe file is encrypted, corrupt or support not yet implemented
com.github.junrar.exception.UnsupportedRarV5Exception: null
	at com.github.junrar.Archive.readHeaders(Archive.java:354)
	at com.github.junrar.Archive.setChannel(Archive.java:199)
	at com.github.junrar.Archive.setVolume(Archive.java:811)
	at com.github.junrar.Archive.<init>(Archive.java:149)
	at com.github.junrar.Archive.<init>(Archive.java:170)
	at com.github.junrar.Junrar.createArchiveOrThrowException(Junrar.java:121)
	at com.github.junrar.Junrar.extract(Junrar.java:40)
	at com.github.junrar.Junrar.extract(Junrar.java:32)
	at com.example.demo.test.CompressTest.rar(CompressTest.java:19)
	at com.example.demo.test.CompressTest.main(CompressTest.java:12)
17:16:52.276 [main] ERROR com.github.junrar.Junrar - Error while creating archive
com.github.junrar.exception.UnsupportedRarV5Exception: null
	at com.github.junrar.Archive.readHeaders(Archive.java:354)
	at com.github.junrar.Archive.setChannel(Archive.java:199)
	at com.github.junrar.Archive.setVolume(Archive.java:811)
	at com.github.junrar.Archive.<init>(Archive.java:149)
	at com.github.junrar.Archive.<init>(Archive.java:170)
	at com.github.junrar.Junrar.createArchiveOrThrowException(Junrar.java:121)
	at com.github.junrar.Junrar.extract(Junrar.java:40)
	at com.github.junrar.Junrar.extract(Junrar.java:32)
	at com.example.demo.test.CompressTest.rar(CompressTest.java:19)
	at com.example.demo.test.CompressTest.main(CompressTest.java:12)
Exception in thread "main" java.lang.RuntimeException: com.github.junrar.exception.UnsupportedRarV5Exception
	at com.example.demo.test.CompressTest.rar(CompressTest.java:23)
	at com.example.demo.test.CompressTest.main(CompressTest.java:12)
Caused by: com.github.junrar.exception.UnsupportedRarV5Exception
	at com.github.junrar.Archive.readHeaders(Archive.java:354)
	at com.github.junrar.Archive.setChannel(Archive.java:199)
	at com.github.junrar.Archive.setVolume(Archive.java:811)
	at com.github.junrar.Archive.<init>(Archive.java:149)
	at com.github.junrar.Archive.<init>(Archive.java:170)
	at com.github.junrar.Junrar.createArchiveOrThrowException(Junrar.java:121)
	at com.github.junrar.Junrar.extract(Junrar.java:40)
	at com.github.junrar.Junrar.extract(Junrar.java:32)
	at com.example.demo.test.CompressTest.rar(CompressTest.java:19)
	... 1 more
 
Process finished with exit code 1

原因是 junrar 不支持 rar5，只要压缩时选择rar4就没问题

重新压缩文件为 rar4

运行代码，发现能正常解压文件了