用java实现encodeURIComponent and decodeURIComponent

package com.util;

 

import java.io.UnsupportedEncodingException;

 

public class UrlDeal {

public static final String ALLOWED_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.!~*'()";

 

public static String encodeURIComponent(String input) {

if (input == null || "".equals(input)) {

return input;

}

 

int l = input.length();

StringBuilder o = new StringBuilder(l * 3);

try {

for (int i = 0; i < l; i++) {

String e = input.substring(i, i + 1);

if (ALLOWED_CHARS.indexOf(e) == -1) {

byte[] b = e.getBytes("utf-8");

o.append(getHex(b));

continue;

}

o.append(e);

}

return o.toString();

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

}

return input;

}

 

private static String getHex(byte buf[]) {

StringBuilder o = new StringBuilder(buf.length * 3);

for (int i = 0; i < buf.length; i++) {

int n = (int) buf[i] & 0xff;

o.append("%");

if (n < 0x10) {

o.append("0");

}

o.append(Long.toString(n, 16).toUpperCase());

}

return o.toString();

}

 

public static String decodeURIComponent(String encodedURI) {

char actualChar;

 

StringBuffer buffer = new StringBuffer();

 

int bytePattern, sumb = 0;

 

for (int i = 0, more = -1; i < encodedURI.length(); i++) {

actualChar = encodedURI.charAt(i);

 

switch (actualChar) {

case '%': {

actualChar = encodedURI.charAt(++i);

int hb = (Character.isDigit(actualChar) ? actualChar - '0'

: 10 + Character.toLowerCase(actualChar) - 'a') & 0xF;

actualChar = encodedURI.charAt(++i);

int lb = (Character.isDigit(actualChar) ? actualChar - '0'

: 10 + Character.toLowerCase(actualChar) - 'a') & 0xF;

bytePattern = (hb << 4) | lb;

break;

}

case '+': {

bytePattern = ' ';

break;

}

default: {

bytePattern = actualChar;

}

}

 

if ((bytePattern & 0xc0) == 0x80) { // 10xxxxxx

sumb = (sumb << 6) | (bytePattern & 0x3f);

if (--more == 0)

buffer.append((char) sumb);

} else if ((bytePattern & 0x80) == 0x00) { // 0xxxxxxx

buffer.append((char) bytePattern);

} else if ((bytePattern & 0xe0) == 0xc0) { // 110xxxxx

sumb = bytePattern & 0x1f;

more = 1;

} else if ((bytePattern & 0xf0) == 0xe0) { // 1110xxxx

sumb = bytePattern & 0x0f;

more = 2;

} else if ((bytePattern & 0xf8) == 0xf0) { // 11110xxx

sumb = bytePattern & 0x07;

more = 3;

} else if ((bytePattern & 0xfc) == 0xf8) { // 111110xx

sumb = bytePattern & 0x03;

more = 4;

} else { // 1111110x

sumb = bytePattern & 0x01;

more = 5;

}

}

return buffer.toString();

}

public static void main(String[] arges){

System.out.println(decodeURIComponent("%E4%BD%A0%E5%A5%BD%20%E7%9C%9F%E7%9A%84"));

System.out.println(encodeURIComponent("你好 真的"));

System.out.println("%E4%BD%A0%E5%A5%BD%20%E7%9C%9F%E7%9A%84");

}

}