如何在Java中進行URL解碼？

在Java中，我想將其轉換爲：

https%3A%2F%2Fmywebsite%2Fdocs%2Fenglish%2Fsite%2Fmybook.do%3Frequest_type

對此：

https://mywebsite/docs/english/site/mybook.do&request_type

這是我到目前爲止的內容：

class StringUTF 
{
    public static void main(String[] args) 
    {
        try{
            String url = 
               "https%3A%2F%2Fmywebsite%2Fdocs%2Fenglish%2Fsite%2Fmybook.do" +
               "%3Frequest_type%3D%26type%3Dprivate";

            System.out.println(url+"Hello World!------->" +
                new String(url.getBytes("UTF-8"),"ASCII"));
        }
        catch(Exception E){
        }
    }
}

但這行不通。 這些%3A和%2F格式叫什麼？如何轉換它們？

---

#1樓

這已經被回答過 （儘管這個問題是第一個！）：

「您應該使用java.net.URI來執行此操做，由於URLDecoder類會進行x-www-form-urlencoded解碼，這是錯誤的（儘管名稱，它用於表單數據）。」

基本上：

String url = "https%3A%2F%2Fmywebsite%2Fdocs%2Fenglish%2Fsite%2Fmybook.do%3Frequest_type";
System.out.println(new java.net.URI(url).getPath());

會給你：

https://mywebsite/docs/english/site/mybook.do?request_type

---

#2樓

import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;

public class URLDecoding { 

    String decoded = "";

    public String decodeMethod(String url) throws UnsupportedEncodingException
    {
        decoded = java.net.URLDecoder.decode(url, "UTF-8"); 
        return  decoded;
//"You should use java.net.URI to do this, as the URLDecoder class does x-www-form-urlencoded decoding which is wrong (despite the name, it's for form data)."
    }

    public String getPathMethod(String url) throws URISyntaxException 
    {
        decoded = new java.net.URI(url).getPath();  
        return  decoded; 
    }

    public static void main(String[] args) throws UnsupportedEncodingException, URISyntaxException 
    {
        System.out.println(" Here is your Decoded url with decode method : "+ new URLDecoding().decodeMethod("https%3A%2F%2Fmywebsite%2Fdocs%2Fenglish%2Fsite%2Fmybook.do%3Frequest_type")); 
        System.out.println("Here is your Decoded url with getPath method : "+ new URLDecoding().getPathMethod("https%3A%2F%2Fmywebsite%2Fdocs%2Fenglish%2Fsite%2Fmybook.do%3Frequest")); 

    } 

}

您能夠明智地選擇方法：）

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#3樓

我使用apache commons

String decodedUrl = new URLCodec().decode(url);

默認字符集爲UTF-8

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#4樓

try {
        String result = URLDecoder.decode(urlString, "UTF-8");
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

---

#5樓

public String decodeString(String URL)
    {

    String urlString="";
    try {
        urlString = URLDecoder.decode(URL,"UTF-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block

        }

        return urlString;

    }