Java 请求读取在线url的 zip压缩包中的内容无依赖

home 编辑时间 2021/02/18

## 前言
如题，希望用java读取一个线上地址的zip压缩包中的某个txt文件
1. 不希望下载该文件到硬盘，直接读取到流，然后在内存里完成解压缩和读取文本等所有步骤
2. 尽可能不用第三方依赖，直接用原生1.8的包来实现

## 正文

参考
[https://blog.csdn.net/qq_32370913/article/details/110491246](https://blog.csdn.net/qq_32370913/article/details/110491246)

最终使用java8自带的 `HttpURLConnection` 和 `ZipInputStream` 来实现该功能

期间遇到一个小坑，报错如下
```java
Exception in thread "main" java.lang.IllegalArgumentException: MALFORMED
	at java.util.zip.ZipCoder.toString(ZipCoder.java:58)
	at java.util.zip.ZipInputStream.readLOC(ZipInputStream.java:300)
	at java.util.zip.ZipInputStream.getNextEntry(ZipInputStream.java:122)
```
原因是编码没有使用 `GBK` ，亲测默认编码和 `UTF-8`均会报这个错误，必须是 `GBK` 或 `GB2312`，推测和压缩者的系统有关?

完整代码如下
```java
import java.io.*;
import java.net.*;
import java.nio.charset.Charset;
import java.util.zip.*;

public class Main {

public static void main(String[] args) throws Throwable {
        String target = "http://idea.medeming.com/jets/images/jihuoma.zip";
        URL url = new URL(target);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        if(conn.getResponseCode() != 200){
            System.out.println("连接失败 code: " + conn.getResponseCode());
        }
        ZipInputStream zipInputStream = new ZipInputStream(conn.getInputStream(), Charset.forName("GB2312"));
        ZipEntry zipEntry;
        while ((zipEntry = zipInputStream.getNextEntry()) != null) {
            String name = zipEntry.getName();
            if (name.startsWith("2018") && name.endsWith("txt")) {
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(zipInputStream));
                String line;
                while ((line = bufferedReader.readLine()) != null) {
                    System.out.println(line);
                }
            }
        }
    }
}
```

执行结果
```java
E8V6UD5UL9-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-KSqF8lSIqoNvDVsEjfbyuGgz6zUWoZOrI89FqeaWMlmEREDbWwWMxX/674LRYbnzxT5txoKFl1NtZvAvITGm1FqpJO9Lt4dPqHtRceW31y6uXkL74s3kWkC+R18X2pSVHHA9ZMBmH5Qdwvz42Ai0qJy8sUw7vC7QPQt3HvafUWbpJte+2FjjAq8aT9EPPVVDNBydSID8lPqvjRLvDn6m/Ey2k121RYxmBmqz0PWPJHQGjhPx6RI3ks0aaDSTLdyUseUTz+ULloa6wL+zhjOQVupIN0fhOlTwPUNf4SGxG7Rt50sockdJ8SmGxB0HAWDp2SLiNm/UnoXlfF5Xr0Elbg==-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
```

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