细节的积累 ---字符串的常用方法总结-优快云博客

字符串的常用方法总结：

package cn.com.huawei.opensource.common.lang;

import java.io.*;

public class StringConverter {

public StringConverter() {
}

byte[] stringToFullByteArray(String s) {
int i = s.length();
byte abyte0[] = new byte[i * 2];
for (int j = 0; j < i; j++) {
char c = s.charAt(j);
abyte0[j * 2] = (byte) ((c & 0xff00) >>

;
abyte0[j * 2 + 1] = (byte) (c & 0xff);
}

return abyte0;
}

public static byte[] hexToByte(String s) throws IOException {
int i = s.length() / 2;
byte abyte0[] = new byte[i];
int j = 0;
if (s.length() % 2 != 0)
throw new IOException(
"hexadecimal string with odd number of characters");
for (int k = 0; k < i; k++) {
char c = s.charAt(j++);
int l = "0123456789abcdef0123456789ABCDEF".indexOf(c); if (l == -1) throw new IOException( "hexadecimal string contains non hex character"); int i1 = (l & 0xf) << 4; c = s.charAt(j++); l = "0123456789abcdef0123456789ABCDEF".indexOf(c); i1 += l & 0xf; abyte0[k] = (byte) i1; } return abyte0; } public static String byteToHex(byte abyte0[]) { int i = abyte0.length; char ac[] = new char[i * 2]; int j = 0; int k = 0; for (; j < i; j++) { int l = abyte0[j] & 0xff; ac[k++] = HEXCHAR[l >> 4 & 0xf]; ac[k++] = HEXCHAR[l & 0xf]; } return new String(ac); } public static int unicodeToAscii(OutputStream outputstream, String s, boolean flag) throws IOException { int i = 0; if (s == null || s.length() == 0) return 0; int j = s.length(); for (int k = 0; k < j; k++) { char c = s.charAt(k); if (c == '\\') { if (k < j - 1 && s.charAt(k + 1) == 'u') { outputstream.write(c); outputstream.write(117); outputstream.write(48); outputstream.write(48); outputstream.write(53); outputstream.write(99); i += 6; } else { outputstream.write(c); i++; } continue; } if (c >= ' ' && c <= '\177') { outputstream.write(c); i++; if (c == '\'' && flag) { outputstream.write(c); i++; } } else { outputstream.write(92); outputstream.write(117); outputstream.write(HEXCHAR[c >> 12 & 0xf]); outputstream.write(HEXCHAR[c >> 8 & 0xf]); outputstream.write(HEXCHAR[c >> 4 & 0xf]); outputstream.write(HEXCHAR[c & 0xf]); i += 6; } } return i; } public static String asciiToUnicode(byte abyte0[], int i, int j) { if (j == 0) return ""; char ac[] = new char[j]; int k = 0; for (int l = 0; l < j; l++) { byte byte0 = abyte0[i + l]; if (byte0 == 92 && l < j - 5) { byte byte1 = abyte0[i + l + 1]; if (byte1 == 117) { l++; int i1 = "0123456789abcdef0123456789ABCDEF" .indexOf(abyte0[i + ++l]) << 12; i1 += "0123456789abcdef0123456789ABCDEF".indexOf(abyte0[i + ++l]) << 8; i1 += "0123456789abcdef0123456789ABCDEF".indexOf(abyte0[i + ++l]) << 4; i1 += "0123456789abcdef0123456789ABCDEF".indexOf(abyte0[i + ++l]); ac[k++] = (char) i1; } else { ac[k++] = (char) byte0; } } else { ac[k++] = (char) byte0; } } return new String(ac, 0, k); } public static String asciiToUnicode(String s) { if (s == null || s.indexOf("\\u") == -1) return s; int i = s.length(); char ac[] = new char[i]; int j = 0; for (int k = 0; k < i; k++) { char c = s.charAt(k); if (c == '\\' && k char c1 = s.charAt(k + 1); if (c1 == 'u') { k++; int l = "0123456789abcdef0123456789ABCDEF".indexOf(s .charAt(++k)) << 12; l += "0123456789abcdef0123456789ABCDEF".indexOf(s .charAt(++k)) << 8; l += "0123456789abcdef0123456789ABCDEF".indexOf(s .charAt(++k)) << 4; l += "0123456789abcdef0123456789ABCDEF".indexOf(s .charAt(++k)); ac[j++] = (char) l; } else { ac[j++] = c; } } else { ac[j++] = c; } } return new String(ac, 0, j); } public static int writeUTF(String s, OutputStream outputstream) throws IOException { int i = s.length(); boolean flag = false; int j = 0; for (int k = 0; k < i; k++) { char c = s.charAt(k); if (c >= '\001' && c <= '\177') { outputstream.write(c); j++; continue; } if (c > '\u07FF') { outputstream.write(0xe0 | c >> 12 & 0xf); outputstream.write(0x80 | c >> 6 & 0x3f); outputstream.write(0x80 | c >> 0 & 0x3f); j += 3; } else { outputstream.write(0xc0 | c >> 6 & 0x1f); outputstream.write(0x80 | c >> 0 & 0x3f); j += 2; } } return j; } public static int getUTFSize(String s) { int i = s != null ? s.length() : 0; int j = 0; for (int k = 0; k < i; k++) { char c = s.charAt(k); if (c >= '\001' && c <= '\177') { j++; continue; } if (c > '\u07FF') j += 3; else j += 2; } return j; } public static String inputStreamToString(InputStream inputstream, int i) throws IOException { InputStreamReader inputstreamreader = new InputStreamReader(inputstream); StringWriter stringwriter = new StringWriter(); char c = '\u2000'; char ac[] = new char[c]; int j = i; do { if (j <= 0) break; int k = inputstreamreader.read(ac, 0, j <= c ? j : ((int) (c))); if (k == -1) break; stringwriter.write(ac, 0, k); j -= k; } while (true); stringwriter.close(); return stringwriter.toString(); } public static String toQuotedString(String s, char c, boolean flag) { if (s == null) return null; int i = flag ? count(s, c) : 0; int j = s.length(); char ac[] = new char[2 + i + j]; int k = 0; int l = 0; ac[l++] = c; for (; k < j; k++) { char c1 = s.charAt(k); ac[l++] = c1; if (flag && c1 == c) ac[l++] = c1; } ac[l] = c; return new String(ac); } static int count(String s, char c) { int i = 0; if (s != null) { int j = s.length(); do { if (--j < 0) break; char c1 = s.charAt(j); if (c1 == c) i++; } while (true); } return i; } private static final char HEXCHAR[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; private static final String HEXINDEX = "0123456789abcdef0123456789ABCDEF"; }