【Java】Illegal character in path

是写读url时报的错

源码和报错内容如下：

package exp3;
import java.io.*;
import java.net.*;
public class GetHtmlFile {
	public static void main(String[] s) throws IOException, URISyntaxException {
		URL url= new URL("http://www.swu.edu.cn");
		InputStream is = url.openStream();
		
		File file = new File(new URI("file:///E:\swu.txt"));
	
		FileOutputStream fos = new FileOutputStream(file); 
		BufferedOutputStream bos = new BufferedOutputStream(fos);
		int ch;
		while((ch=is.read())!=-1)
		{
			bos.write(ch);
			//bos.flush();
			System.out.print((char)ch);
		}
		bos.close();
	}
}

Exception in thread "main" java.net.URISyntaxException: Illegal character in path at index 10: file:///E: wu.txt
	at java.base/java.net.URI$Parser.fail(URI.java:2963)
	at java.base/java.net.URI$Parser.checkChars(URI.java:3134)
	at java.base/java.net.URI$Parser.parseHierarchical(URI.java:3216)
	at java.base/java.net.URI$Parser.parse(URI.java:3164)
	at java.base/java.net.URI.<init>(URI.java:623)
	at exp3/exp3.GetHtmlFile.main(GetHtmlFile.java:9)

字符串中 \ 是转义字符，所以要 \\ 才行

\s被识别成非法转义符了，报错里就没显示