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?
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
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.
其他回答
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();
}
}
Hello+World是浏览器为GET请求编码表单数据(application/x-www-form-urlencoded)的方式,这是URI查询部分的普遍接受的形式。
http://host/path/?message=Hello+World
如果将此请求发送到Java servlet, servlet将正确解码参数值。通常唯一出现问题的情况是编码不匹配。
严格来说,HTTP或URI规范中没有要求使用application/x-www-form- urlenencoded键-值对对查询部分进行编码;查询部分只需采用web服务器接受的形式即可。实际上,这不大可能成为一个问题。
对于URI的其他部分(例如路径)使用这种编码通常是不正确的。在这种情况下,您应该使用RFC 3986中描述的编码方案。
http://host/Hello%20World
更多的在这里。
如果你想编码URI路径组件,你也可以使用标准的JDK函数,例如:
public static String encodeURLPathComponent(String path) {
try {
return new URI(null, null, path, null).toASCIIString();
} catch (URISyntaxException e) {
// do some error handling
}
return "";
}
URI类还可以用于编码URI的不同部分或整个URI。
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();
查询参数
org.apache.commons.httpclient.util.URIUtil
URIUtil.encodeQuery(input);
如果你想转义URI中的字符
public static String escapeURIPathParam(String input) {
StringBuilder resultStr = new StringBuilder();
for (char ch : input.toCharArray()) {
if (isUnsafe(ch)) {
resultStr.append('%');
resultStr.append(toHex(ch / 16));
resultStr.append(toHex(ch % 16));
} else{
resultStr.append(ch);
}
}
return resultStr.toString();
}
private static char toHex(int ch) {
return (char) (ch < 10 ? '0' + ch : 'A' + ch - 10);
}
private static boolean isUnsafe(char ch) {
if (ch > 128 || ch < 0)
return true;
return " %$&+,/:;=?@<>#%".indexOf(ch) >= 0;
}