我在期待

System.out.println(java.net.URLEncoder.encode("Hello World", "UTF-8"));

输出:

你好%20世界

(20是ASCII十六进制空格码)

然而,我得到的是:

你好+世界

我用错方法了吗?我应该使用的正确方法是什么?


当前回答

使用MyUrlEncode。URLencoding(String url, String enc)来处理这个问题

    public class MyUrlEncode {
    static BitSet dontNeedEncoding = null;
    static final int caseDiff = ('a' - 'A');
    static {
        dontNeedEncoding = new BitSet(256);
        int i;
        for (i = 'a'; i <= 'z'; i++) {
            dontNeedEncoding.set(i);
        }
        for (i = 'A'; i <= 'Z'; i++) {
            dontNeedEncoding.set(i);
        }
        for (i = '0'; i <= '9'; i++) {
            dontNeedEncoding.set(i);
        }
        dontNeedEncoding.set('-');
        dontNeedEncoding.set('_');
        dontNeedEncoding.set('.');
        dontNeedEncoding.set('*');
        dontNeedEncoding.set('&');
        dontNeedEncoding.set('=');
    }
    public static String char2Unicode(char c) {
        if(dontNeedEncoding.get(c)) {
            return String.valueOf(c);
        }
        StringBuffer resultBuffer = new StringBuffer();
        resultBuffer.append("%");
        char ch = Character.forDigit((c >> 4) & 0xF, 16);
            if (Character.isLetter(ch)) {
            ch -= caseDiff;
        }
        resultBuffer.append(ch);
            ch = Character.forDigit(c & 0xF, 16);
            if (Character.isLetter(ch)) {
            ch -= caseDiff;
        }
         resultBuffer.append(ch);
        return resultBuffer.toString();
    }
    private static String URLEncoding(String url,String enc) throws UnsupportedEncodingException {
        StringBuffer stringBuffer = new StringBuffer();
        if(!dontNeedEncoding.get('/')) {
            dontNeedEncoding.set('/');
        }
        if(!dontNeedEncoding.get(':')) {
            dontNeedEncoding.set(':');
        }
        byte [] buff = url.getBytes(enc);
        for (int i = 0; i < buff.length; i++) {
            stringBuffer.append(char2Unicode((char)buff[i]));
        }
        return stringBuffer.toString();
    }
    private static String URIEncoding(String uri , String enc) throws UnsupportedEncodingException { //对请求参数进行编码
        StringBuffer stringBuffer = new StringBuffer();
        if(dontNeedEncoding.get('/')) {
            dontNeedEncoding.clear('/');
        }
        if(dontNeedEncoding.get(':')) {
            dontNeedEncoding.clear(':');
        }
        byte [] buff = uri.getBytes(enc);
        for (int i = 0; i < buff.length; i++) {
            stringBuffer.append(char2Unicode((char)buff[i]));
        }
        return stringBuffer.toString();
    }

    public static String URLencoding(String url , String enc) throws UnsupportedEncodingException {
        int index = url.indexOf('?');
        StringBuffer result = new StringBuffer();
        if(index == -1) {
            result.append(URLEncoding(url, enc));
        }else {
            result.append(URLEncoding(url.substring(0 , index),enc));
            result.append("?");
            result.append(URIEncoding(url.substring(index+1),enc));
        }
        return result.toString();
    }

}

其他回答

该类执行application/x-www-form- urlenencoded -type编码,而不是百分比编码,因此替换为+是正确的行为。

从javadoc:

When encoding a String, the following rules apply: The alphanumeric characters "a" through "z", "A" through "Z" and "0" through "9" remain the same. The special characters ".", "-", "*", and "_" remain the same. The space character " " is converted into a plus sign "+". All other characters are unsafe and are first converted into one or more bytes using some encoding scheme. Then each byte is represented by the 3-character string "%xy", where xy is the two-digit hexadecimal representation of the byte. The recommended encoding scheme to use is UTF-8. However, for compatibility reasons, if an encoding is not specified, then the default encoding of the platform is used.

虽然很老了,但还是迅速回应:

Spring提供了UriUtils -使用它你可以指定如何编码以及它与URI的哪个部分相关。

encodePathSegment
encodePort
encodeFragment
encodeUriVariables
....

我使用它们是因为我们已经在使用Spring,即不需要额外的库!

如果您正在使用jetty,那么org.eclipse.jetty.util.URIUtil将解决这个问题。

String encoded_string = URIUtil.encodePath(not_encoded_string).toString();

URLEncoder使用字符集“ISO-8859-1”

一个空格在url中被编码为%20,在表单提交的数据中被编码为+(内容类型为application/x-www-form-urlencoded)。你需要前者。

使用番石榴:

dependencies {
     compile 'com.google.guava:guava:23.0'
     // or, for Android:
     compile 'com.google.guava:guava:23.0-android'
}

你可以使用UrlEscapers:

String encodedString = UrlEscapers.urlFragmentEscaper().escape(inputString);

不要使用String。替换,这只会编码空间。使用库代替。