String里的split()函数的问题

Question

用一般的字符去拆分字符串都没有问题，可用"|"的时候就不行了，会把每个字符都拆开，怎么解决？

Answer 1

ch = peek();
            switch (ch) {
            case '(':
                // Because group handles its own closure,
                // we need to treat it differently
                node = group0();
                // Check for comment or flag group
                if (node == null)
                    continue;
                if (head == null)
                    head = node;
                else
                    tail.next = node;
                // Double return: Tail was returned in root
                tail = root;
                continue;
            case '[':
                node = clazz(true);
                break;
            case '\\':
                ch = nextEscaped();
                if (ch == 'p' || ch == 'P') {
                    boolean comp = (ch == 'P');
                    boolean oneLetter = true;
                    ch = next(); // Consume { if present
                    if (ch != '{') {
                        unread();
                    } else {
                        oneLetter = false;
                    }
                    node = family(comp, oneLetter);
                } else {
                    unread();
                    node = atom();
                }
                break;
            case '^':
                next();
                if (has(MULTILINE)) {
                    if (has(UNIX_LINES))
                        node = new UnixCaret();
                    else
                        node = new Caret();
                } else {
                    node = new Begin();
                }
                break;
            case '$':
                next();
                if (has(UNIX_LINES))
                    node = new UnixDollar(has(MULTILINE));
                else
                    node = new Dollar(has(MULTILINE));
                break;
            case '.':
                next();
                if (has(DOTALL)) {
                    node = new All();
                } else {
                    if (has(UNIX_LINES))
                        node = new UnixDot();
                    else {
                        node = new Dot();
                    }
                }
                break;
            case '|':
            case ')':
                break LOOP;
            case ']': // Now interpreting dangling ] and } as literals
            case '}':
                node = atom();
                break;
            case '?':
            case '*':
            case '+':
                next();
                return error("Dangling meta character '" + ((char)ch) + "'");
            case 0:
                if (cursor >= patternLength) {
                    break LOOP;
                }
                // Fall through
            default:
                node = atom();
                break;
            }这是处理时的一段代码，这里的这些字符都进行过一些处理的

Answer 2

用 StringTokenizer 就可以，这个可以区分关键字符，不需要转义，具体用法参见API吧。